/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.avro;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.avro.Schema.Field;
import org.apache.avro.generic.GenericData;
import org.apache.avro.generic.GenericRecord;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.io.JsonStringEncoder;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.node.TextNode;
/**
* <p>
* A fluent interface for building {@link Schema} instances. The flow of the API
* is designed to mimic the <a
* href="http://avro.apache.org/docs/current/spec.html#schemas">Avro Schema
* Specification</a>
* </p>
* For example, the below JSON schema and the fluent builder code to create it
* are very similar:
*
* <pre>
* {
* "type": "record",
* "name": "HandshakeRequest", "namespace":"org.apache.avro.ipc",
* "fields": [
* {"name": "clientHash",
* "type": {"type": "fixed", "name": "MD5", "size": 16}},
* {"name": "clientProtocol", "type": ["null", "string"]},
* {"name": "serverHash", "type": "MD5"},
* {"name": "meta", "type": ["null", {"type": "map", "values": "bytes"}]}
* ]
* }
* </pre>
*
* <pre>
* Schema schema = SchemaBuilder
* .record("HandshakeRequest").namespace("org.apache.avro.ipc)
* .fields()
* .name("clientHash").type().fixed("MD5").size(16).noDefault()
* .name("clientProtocol").type().nullable().stringType().noDefault()
* .name("serverHash").type("MD5")
* .name("meta").type().nullable().map().values().bytesType().noDefault()
* .endRecord();
* </pre>
* <p/>
*
* <h5>Usage Guide</h5>
* SchemaBuilder chains together many smaller builders and maintains nested
* context in order to mimic the Avro Schema specification. Every Avro type in
* JSON has required and optional JSON properties, as well as user-defined
* properties.
* <p/>
* <h6>Selecting and Building an Avro Type</h6>
* The API analogy for the right hand side of the Avro Schema JSON
* <pre>
* "type":
* </pre>
* is a {@link TypeBuilder}, {@link FieldTypeBuilder}, or
* {@link UnionFieldTypeBuilder}, depending on the context. These types all
* share a similar API for selecting and building types.
* <p/>
* <h5>Primitive Types</h5>
* All Avro primitive types are trivial to configure. A primitive type in
* Avro JSON can be declared two ways, one that supports custom properties
* and one that does not:
* <pre>
* {"type":"int"}
* {"type":{"name":"int"}}
* {"type":{"name":"int", "customProp":"val"}}
* </pre>
* The analogous code form for the above three JSON lines are the below
* three lines:
* <pre>
* .intType()
* .intBuilder().endInt()
* .intBuilder().prop("customProp", "val").endInt()
* </pre>
* Every primitive type has a shortcut to create the trivial type, and
* a builder when custom properties are required. The first line above is
* a shortcut for the second, analogous to the JSON case.
* <h6>Named Types</h6>
* Avro named types have names, namespace, aliases, and doc. In this API
* these share a common parent, {@link NamespacedBuilder}.
* The builders for named types require a name to be constructed, and optional
* configuration via:
* <li>{@link NamespacedBuilder#doc()}</li>
* <li>{@link NamespacedBuilder#namespace(String)}</li>
* <li>{@link NamespacedBuilder#aliases(String...)}</li>
* <li>{@link PropBuilder#prop(String, String)}</li>
* <p/>
* Each named type completes configuration of the optional properties
* with its own method:
* <li>{@link FixedBuilder#size(int)}</li>
* <li>{@link EnumBuilder#symbols(String...)}</li>
* <li>{@link RecordBuilder#fields()}</li>
* Example use of a named type with all optional parameters:
* <pre>
* .enumeration("Suit").namespace("org.apache.test")
* .aliases("org.apache.test.OldSuit")
* .doc("CardSuits")
* .prop("customProp", "val")
* .symbols("SPADES", "HEARTS", "DIAMONDS", "CLUBS")
* </pre>
* Which is equivalent to the JSON:
* <pre>
* { "type":"enum",
* "name":"Suit", "namespace":"org.apache.test",
* "aliases":["org.apache.test.OldSuit"],
* "doc":"Card Suits",
* "customProp":"val",
* "symbols":["SPADES", "HEARTS", "DIAMONDS", "CLUBS"]
* }
* </pre>
* <h6>Nested Types</h6>
* The Avro nested types, map and array, can have custom properties like
* all avro types, are not named, and must specify a nested type.
* After configuration of optional properties, an array or map
* builds or selects its nested type with {@link ArrayBuilder#items()}
* and {@link MapBuilder#values()}, respectively.
*
* <h6>Fields</h6>
* {@link RecordBuilder#fields()} returns a {@link FieldAssembler} for
* defining the fields of the record and completing it.
* Each field must have a name, specified via {@link FieldAssembler#name(String)},
* which returns a {@link FieldBuilder} for defining aliases, custom properties,
* and documentation of the field. After configuring these optional values for
* a field, the type is selected or built with {@link FieldBuilder#type()}.
* <p/>
* Fields have default values that must be specified to complete the field.
* {@link FieldDefault#noDefault()} is available for all field types, and
* a specific method is available for each type to use a default, for example
* {@link IntDefault#intDefault(int)}
* <p/>
* There are field shortcut methods on {@link FieldAssembler} for primitive types.
* These shortcuts create required, optional, and nullable fields, but do not
* support field aliases, doc, or custom properties.
*
* <h6>Unions</h6>
* Union types are built via {@link TypeBuilder#unionOf()} or
* {@link FieldTypeBuilder#unionOf()} in the context of type selection.
* This chains together multiple types, in union order. For example:
* <pre>
* .unionOf()
* .fixed("IPv4").size(4).and()
* .fixed("IPv6").size(16).and()
* .nullType().endUnion()
* </pre>
* is equivalent to the Avro schema JSON:
* <pre>
* [
* {"type":"fixed", "name":"IPv4", "size":4},
* {"type":"fixed", "name":"IPv6", "size":16},
* "null"
* ]
* </pre>
* In a field context, the first type of a union defines what default type
* is allowed.
* </p>
* Unions have two shortcuts for common cases. nullable()
* creates a union of a type and null. In a field type context, optional()
* is available and creates a union of null and a type, with a null default.
* The below two are equivalent:
* <pre>
* .unionOf().intType().and().nullType().endUnion()
* .nullable().intType()
* </pre>
* The below two field declarations are equivalent:
* <pre>
* .name("f").type().unionOf().nullType().and().longType().endUnion().nullDefault()
* .name("f").type().optional().longType()
* </pre>
*
* <h6>Explicit Types and Types by Name</h6>
* Types can also be specified explicitly by passing in a Schema, or by name:
* <pre>
* .type(Schema.create(Schema.Type.INT)) // explicitly specified
* .type("MD5") // reference by full name or short name
* .type("MD5", "org.apache.avro.test") // reference by name and namespace
* </pre>
* When a type is specified by name, and the namespace is absent or null, the
* namespace is inherited from the enclosing context. A namespace will
* propagate as a default to child fields, nested types, or later defined types
* in a union. To specify a name that has no namespace and ignore the inherited
* namespace, set the namespace to "".
* <p/>
* {@link SchemaBuilder#builder(String)} returns a type builder with a default
* namespace. {@link SchemaBuilder#builder()} returns a type builder with no
* default namespace.
*/
public class SchemaBuilder {
private SchemaBuilder() {
}
/**
* Create a builder for Avro schemas.
*/
public static TypeBuilder<Schema> builder() {
return new TypeBuilder<Schema>(new SchemaCompletion(), new NameContext());
}
/**
* Create a builder for Avro schemas with a default namespace. Types created
* without namespaces will inherit the namespace provided.
*/
public static TypeBuilder<Schema> builder(String namespace) {
return new TypeBuilder<Schema>(new SchemaCompletion(),
new NameContext().namespace(namespace));
}
/**
* Create a builder for an Avro record with the specified name.
* This is equivalent to:
* <pre>
* builder().record(name);
* </pre>
* @param name the record name
*/
public static RecordBuilder<Schema> record(String name) {
return builder().record(name);
}
/**
* Create a builder for an Avro enum with the specified name and symbols (values).
* This is equivalent to:
* <pre>
* builder().enumeration(name);
* </pre>
* @param name the enum name
*/
public static EnumBuilder<Schema> enumeration(String name) {
return builder().enumeration(name);
}
/**
* Create a builder for an Avro fixed type with the specified name and size.
* This is equivalent to:
* <pre>
* builder().fixed(name);
* </pre>
* @param name the fixed name
*/
public static FixedBuilder<Schema> fixed(String name) {
return builder().fixed(name);
}
/**
* Create a builder for an Avro array
* This is equivalent to:
* <pre>
* builder().array();
* </pre>
*/
public static ArrayBuilder<Schema> array() {
return builder().array();
}
/**
* Create a builder for an Avro map
* This is equivalent to:
* <pre>
* builder().map();
* </pre>
*/
public static MapBuilder<Schema> map() {
return builder().map();
}
/**
* Create a builder for an Avro union
* This is equivalent to:
* <pre>
* builder().unionOf();
* </pre>
*/
public static BaseTypeBuilder<UnionAccumulator<Schema>> unionOf() {
return builder().unionOf();
}
/**
* Create a builder for a union of a type and null.
* This is a shortcut for:
* <pre>
* builder().nullable();
* </pre>
* and the following two lines are equivalent:
* <pre>
* nullable().intType();
* </pre>
* <pre>
* unionOf().intType().and().nullType().endUnion();
* </pre>
*/
public static BaseTypeBuilder<Schema> nullable() {
return builder().nullable();
}
/**
* An abstract builder for all Avro types. All Avro types
* can have arbitrary string key-value properties.
*/
public static abstract class PropBuilder<S extends PropBuilder<S>> {
private Map<String, JsonNode> props = null;
protected PropBuilder() {
}
/**
* Set name-value pair properties for this type or field.
*/
public final S prop(String name, String val) {
return prop(name, TextNode.valueOf(val));
}
// for internal use by the Parser
final S prop(String name, JsonNode val) {
if(!hasProps()) {
props = new HashMap<String, JsonNode>();
}
props.put(name, val);
return self();
}
private boolean hasProps() {
return (props != null);
}
final <T extends JsonProperties> T addPropsTo(T jsonable) {
if (hasProps()) {
for(Map.Entry<String, JsonNode> prop : props.entrySet()) {
jsonable.addProp(prop.getKey(), prop.getValue());
}
}
return jsonable;
}
/** a self-type for chaining builder subclasses. Concrete subclasses
* must return 'this' **/
protected abstract S self();
}
/**
* An abstract type that provides builder methods for configuring the name,
* doc, and aliases of all Avro types that have names (fields, Fixed, Record,
* and Enum).
* <p/>
* All Avro named types and fields have 'doc', 'aliases', and 'name'
* components. 'name' is required, and provided to this builder. 'doc' and
* 'alises' are optional.
*/
public static abstract class NamedBuilder<S extends NamedBuilder<S>> extends
PropBuilder<S> {
private final String name;
private final NameContext names;
private String doc;
private String[] aliases;
protected NamedBuilder(NameContext names, String name) {
checkRequired(name, "Type must have a name");
this.names = names;
this.name = name;
}
/** configure this type's optional documentation string **/
public final S doc(String doc) {
this.doc = doc;
return self();
}
/** configure this type's optional name aliases **/
public final S aliases(String... aliases) {
this.aliases = aliases;
return self();
}
final String doc() {
return doc;
}
final String name() {
return name;
}
final NameContext names() {
return names;
}
final Schema addAliasesTo(Schema schema) {
if (null != aliases) {
for (String alias : aliases) {
schema.addAlias(alias);
}
}
return schema;
}
final Field addAliasesTo(Field field) {
if (null != aliases) {
for (String alias : aliases) {
field.addAlias(alias);
}
}
return field;
}
}
/**
* An abstract type that provides builder methods for configuring the
* namespace for all Avro types that have namespaces (Fixed, Record, and
* Enum).
*/
public static abstract class NamespacedBuilder<R, S extends NamespacedBuilder<R, S>>
extends NamedBuilder<S> {
private final Completion<R> context;
private String namespace;
protected NamespacedBuilder(Completion<R> context, NameContext names,
String name) {
super(names, name);
this.context = context;
}
/**
* Set the namespace of this type. To clear the namespace, set empty string.
* <p/>
* When the namespace is null or unset, the namespace of the type defaults
* to the namespace of the enclosing context.
**/
public final S namespace(String namespace) {
this.namespace = namespace;
return self();
}
final String space() {
if (null == namespace) {
return names().namespace;
}
return namespace;
}
final Schema completeSchema(Schema schema) {
addPropsTo(schema);
addAliasesTo(schema);
names().put(schema);
return schema;
}
final Completion<R> context() {
return context;
}
}
/**
* An abstraction for sharing code amongst all primitive type builders.
*/
private static abstract class PrimitiveBuilder<R, P extends PrimitiveBuilder<R, P>>
extends PropBuilder<P> {
private final Completion<R> context;
private final Schema immutable;
protected PrimitiveBuilder(Completion<R> context, NameContext names,
Schema.Type type) {
this.context = context;
this.immutable = names.getFullname(type.getName());
}
private R end() {
Schema schema = immutable;
if (super.hasProps()) {
schema = Schema.create(immutable.getType());
addPropsTo(schema);
}
return context.complete(schema);
}
}
/**
* Builds an Avro boolean type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endBoolean()}
**/
public static final class BooleanBuilder<R> extends
PrimitiveBuilder<R, BooleanBuilder<R>> {
private BooleanBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.BOOLEAN);
}
private static <R> BooleanBuilder<R> create(Completion<R> context,
NameContext names) {
return new BooleanBuilder<R>(context, names);
}
@Override
protected BooleanBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endBoolean() {
return super.end();
}
}
/**
* Builds an Avro int type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endInt()}
**/
public static final class IntBuilder<R> extends
PrimitiveBuilder<R, IntBuilder<R>> {
private IntBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.INT);
}
private static <R> IntBuilder<R> create(Completion<R> context,
NameContext names) {
return new IntBuilder<R>(context, names);
}
@Override
protected IntBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endInt() {
return super.end();
}
}
/**
* Builds an Avro long type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endLong()}
**/
public static final class LongBuilder<R> extends
PrimitiveBuilder<R, LongBuilder<R>> {
private LongBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.LONG);
}
private static <R> LongBuilder<R> create(Completion<R> context,
NameContext names) {
return new LongBuilder<R>(context, names);
}
@Override
protected LongBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endLong() {
return super.end();
}
}
/**
* Builds an Avro float type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endFloat()}
**/
public static final class FloatBuilder<R> extends
PrimitiveBuilder<R, FloatBuilder<R>> {
private FloatBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.FLOAT);
}
private static <R> FloatBuilder<R> create(Completion<R> context,
NameContext names) {
return new FloatBuilder<R>(context, names);
}
@Override
protected FloatBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endFloat() {
return super.end();
}
}
/**
* Builds an Avro double type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endDouble()}
**/
public static final class DoubleBuilder<R> extends
PrimitiveBuilder<R, DoubleBuilder<R>> {
private DoubleBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.DOUBLE);
}
private static <R> DoubleBuilder<R> create(Completion<R> context,
NameContext names) {
return new DoubleBuilder<R>(context, names);
}
@Override
protected DoubleBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endDouble() {
return super.end();
}
}
/**
* Builds an Avro string type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endString()}
**/
public static final class StringBldr<R> extends
PrimitiveBuilder<R, StringBldr<R>> {
private StringBldr(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.STRING);
}
private static <R> StringBldr<R> create(Completion<R> context,
NameContext names) {
return new StringBldr<R>(context, names);
}
@Override
protected StringBldr<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endString() {
return super.end();
}
}
/**
* Builds an Avro bytes type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endBytes()}
**/
public static final class BytesBuilder<R> extends
PrimitiveBuilder<R, BytesBuilder<R>> {
private BytesBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.BYTES);
}
private static <R> BytesBuilder<R> create(Completion<R> context,
NameContext names) {
return new BytesBuilder<R>(context, names);
}
@Override
protected BytesBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endBytes() {
return super.end();
}
}
/**
* Builds an Avro null type with optional properties. Set properties with
* {@link #prop(String, String)}, and finalize with {@link #endNull()}
**/
public static final class NullBuilder<R> extends
PrimitiveBuilder<R, NullBuilder<R>> {
private NullBuilder(Completion<R> context, NameContext names) {
super(context, names, Schema.Type.NULL);
}
private static <R> NullBuilder<R> create(Completion<R> context,
NameContext names) {
return new NullBuilder<R>(context, names);
}
@Override
protected NullBuilder<R> self() {
return this;
}
/** complete building this type, return control to context **/
public R endNull() {
return super.end();
}
}
/**
* Builds an Avro Fixed type with optional properties, namespace, doc, and
* aliases.
* <p/>
* Set properties with {@link #prop(String, String)}, namespace with
* {@link #namespace(String)}, doc with {@link #doc(String)}, and aliases with
* {@link #aliases(String[])}.
* <p/>
* The Fixed schema is finalized when its required size is set via
* {@link #size(int)}.
**/
public static final class FixedBuilder<R> extends
NamespacedBuilder<R, FixedBuilder<R>> {
private FixedBuilder(Completion<R> context, NameContext names, String name) {
super(context, names, name);
}
private static <R> FixedBuilder<R> create(Completion<R> context,
NameContext names, String name) {
return new FixedBuilder<R>(context, names, name);
}
@Override
protected FixedBuilder<R> self() {
return this;
}
/** Configure this fixed type's size, and end its configuration. **/
public R size(int size) {
Schema schema = Schema.createFixed(name(), super.doc(), space(), size);
completeSchema(schema);
return context().complete(schema);
}
}
/**
* Builds an Avro Enum type with optional properties, namespace, doc, and
* aliases.
* <p/>
* Set properties with {@link #prop(String, String)}, namespace with
* {@link #namespace(String)}, doc with {@link #doc(String)}, and aliases with
* {@link #aliases(String[])}.
* <p/>
* The Enum schema is finalized when its required symbols are set via
* {@link #symbols(String[])}.
**/
public static final class EnumBuilder<R> extends
NamespacedBuilder<R, EnumBuilder<R>> {
private EnumBuilder(Completion<R> context, NameContext names, String name) {
super(context, names, name);
}
private static <R> EnumBuilder<R> create(Completion<R> context,
NameContext names, String name) {
return new EnumBuilder<R>(context, names, name);
}
@Override
protected EnumBuilder<R> self() {
return this;
}
/** Configure this enum type's symbols, and end its configuration. **/
public R symbols(String... symbols) {
Schema schema = Schema.createEnum(name(), doc(), space(),
Arrays.asList(symbols));
completeSchema(schema);
return context().complete(schema);
}
}
/**
* Builds an Avro Map type with optional properties.
* <p/>
* Set properties with {@link #prop(String, String)}.
* <p/>
* The Map schema's properties are finalized when {@link #values()} or
* {@link #values(Schema)} is called.
**/
public static final class MapBuilder<R> extends PropBuilder<MapBuilder<R>> {
private final Completion<R> context;
private final NameContext names;
private MapBuilder(Completion<R> context, NameContext names) {
this.context = context;
this.names = names;
}
private static <R> MapBuilder<R> create(Completion<R> context,
NameContext names) {
return new MapBuilder<R>(context, names);
}
@Override
protected MapBuilder<R> self() {
return this;
}
/**
* Return a type builder for configuring the map's nested values schema.
* This builder will return control to the map's enclosing context when
* complete.
**/
public TypeBuilder<R> values() {
return new TypeBuilder<R>(new MapCompletion<R>(this, context), names);
}
/**
* Complete configuration of this map, setting the schema of the map values
* to the schema provided. Returns control to the enclosing context.
**/
public R values(Schema valueSchema) {
return new MapCompletion<R>(this, context).complete(valueSchema);
}
}
/**
* Builds an Avro Array type with optional properties.
* <p/>
* Set properties with {@link #prop(String, String)}.
* <p/>
* The Array schema's properties are finalized when {@link #items()} or
* {@link #items(Schema)} is called.
**/
public static final class ArrayBuilder<R> extends
PropBuilder<ArrayBuilder<R>> {
private final Completion<R> context;
private final NameContext names;
public ArrayBuilder(Completion<R> context, NameContext names) {
this.context = context;
this.names = names;
}
private static <R> ArrayBuilder<R> create(Completion<R> context,
NameContext names) {
return new ArrayBuilder<R>(context, names);
}
@Override
protected ArrayBuilder<R> self() {
return this;
}
/**
* Return a type builder for configuring the array's nested items schema.
* This builder will return control to the array's enclosing context when
* complete.
**/
public TypeBuilder<R> items() {
return new TypeBuilder<R>(new ArrayCompletion<R>(this, context), names);
}
/**
* Complete configuration of this array, setting the schema of the array
* items to the schema provided. Returns control to the enclosing context.
**/
public R items(Schema itemsSchema) {
return new ArrayCompletion<R>(this, context).complete(itemsSchema);
}
}
/**
* internal class for passing the naming context around. This allows for the
* following:
* <li>Cache and re-use primitive schemas when they do not set
* properties.</li>
* <li>Provide a default namespace for nested contexts (as
* the JSON Schema spec does).</li>
* <li>Allow previously defined named types or primitive types
* to be referenced by name.</li>
**/
private static class NameContext {
private static final Set<String> PRIMITIVES = new HashSet<String>();
{
PRIMITIVES.add("null");
PRIMITIVES.add("boolean");
PRIMITIVES.add("int");
PRIMITIVES.add("long");
PRIMITIVES.add("float");
PRIMITIVES.add("double");
PRIMITIVES.add("bytes");
PRIMITIVES.add("string");
}
private final HashMap<String, Schema> schemas;
private final String namespace;
private NameContext() {
this.schemas = new HashMap<String, Schema>();
this.namespace = null;
schemas.put("null", Schema.create(Schema.Type.NULL));
schemas.put("boolean", Schema.create(Schema.Type.BOOLEAN));
schemas.put("int", Schema.create(Schema.Type.INT));
schemas.put("long", Schema.create(Schema.Type.LONG));
schemas.put("float", Schema.create(Schema.Type.FLOAT));
schemas.put("double", Schema.create(Schema.Type.DOUBLE));
schemas.put("bytes", Schema.create(Schema.Type.BYTES));
schemas.put("string", Schema.create(Schema.Type.STRING));
}
private NameContext(HashMap<String, Schema> schemas, String namespace) {
this.schemas = schemas;
this.namespace = "".equals(namespace) ? null : namespace;
}
private NameContext namespace(String namespace) {
return new NameContext(schemas, namespace);
}
private Schema get(String name, String namespace) {
return getFullname(resolveName(name, namespace));
}
private Schema getFullname(String fullName) {
Schema schema = schemas.get(fullName);
if(schema == null) {
throw new SchemaParseException("Undefined name: " + fullName);
}
return schema;
}
private void put(Schema schema) {
String fullName = schema.getFullName();
if(schemas.containsKey(fullName)){
throw new SchemaParseException("Can't redefine: " + fullName);
}
schemas.put(fullName, schema);
}
private String resolveName(String name, String space) {
if (PRIMITIVES.contains(name) && space == null) {
return name;
}
int lastDot = name.lastIndexOf('.');
if (lastDot < 0) { // short name
if (space == null) {
space = namespace;
}
if (space != null && !"".equals(space)) {
return space + "." + name;
}
}
return name;
}
}
/**
* A common API for building types within a context. BaseTypeBuilder can build
* all types other than Unions. {@link TypeBuilder} can additionally build
* Unions.
* <p/>
* The builder has two contexts:
* <li>A naming context provides a default namespace and allows for previously
* defined named types to be referenced from {@link #type(String)}</li>
* <li>A completion context representing the scope that the builder was
* created in. A builder created in a nested context (for example,
* {@link MapBuilder#values()} will have a completion context assigned by the
* {@link MapBuilder}</li>
**/
public static class BaseTypeBuilder<R> {
private final Completion<R> context;
private final NameContext names;
private BaseTypeBuilder(Completion<R> context, NameContext names) {
this.context = context;
this.names = names;
}
/** Use the schema provided as the type. **/
public final R type(Schema schema) {
return context.complete(schema);
}
/**
* Look up the type by name. This type must be previously defined in the
* context of this builder.
* <p/>
* The name may be fully qualified or a short name. If it is a short name,
* the default namespace of the current context will additionally be
* searched.
**/
public final R type(String name) {
return type(name, null);
}
/**
* Look up the type by name and namespace. This type must be previously
* defined in the context of this builder.
* <p/>
* The name may be fully qualified or a short name. If it is a fully
* qualified name, the namespace provided is ignored. If it is a short name,
* the namespace provided is used if not null, else the default namespace of
* the current context will be used.
**/
public final R type(String name, String namespace) {
return type(names.get(name, namespace));
}
/**
* A plain boolean type without custom properties. This is equivalent to:
* <pre>
* booleanBuilder().endBoolean();
* </pre>
*/
public final R booleanType() {
return booleanBuilder().endBoolean();
}
/**
* Build a boolean type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #booleanType()}.
*/
public final BooleanBuilder<R> booleanBuilder() {
return BooleanBuilder.create(context, names);
}
/**
* A plain int type without custom properties. This is equivalent to:
* <pre>
* intBuilder().endInt();
* </pre>
*/
public final R intType() {
return intBuilder().endInt();
}
/**
* Build an int type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #intType()}.
*/
public final IntBuilder<R> intBuilder() {
return IntBuilder.create(context, names);
}
/**
* A plain long type without custom properties. This is equivalent to:
* <pre>
* longBuilder().endLong();
* </pre>
*/
public final R longType() {
return longBuilder().endLong();
}
/**
* Build a long type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #longType()}.
*/
public final LongBuilder<R> longBuilder() {
return LongBuilder.create(context, names);
}
/**
* A plain float type without custom properties. This is equivalent to:
* <pre>
* floatBuilder().endFloat();
* </pre>
*/
public final R floatType() {
return floatBuilder().endFloat();
}
/**
* Build a float type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #floatType()}.
*/
public final FloatBuilder<R> floatBuilder() {
return FloatBuilder.create(context, names);
}
/**
* A plain double type without custom properties. This is equivalent to:
* <pre>
* doubleBuilder().endDouble();
* </pre>
*/
public final R doubleType() {
return doubleBuilder().endDouble();
}
/**
* Build a double type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #doubleType()}.
*/
public final DoubleBuilder<R> doubleBuilder() {
return DoubleBuilder.create(context, names);
}
/**
* A plain string type without custom properties. This is equivalent to:
* <pre>
* stringBuilder().endString();
* </pre>
*/
public final R stringType() {
return stringBuilder().endString();
}
/**
* Build a string type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #stringType()}.
*/
public final StringBldr<R> stringBuilder() {
return StringBldr.create(context, names);
}
/**
* A plain bytes type without custom properties. This is equivalent to:
* <pre>
* bytesBuilder().endBytes();
* </pre>
*/
public final R bytesType() {
return bytesBuilder().endBytes();
}
/**
* Build a bytes type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #bytesType()}.
*/
public final BytesBuilder<R> bytesBuilder() {
return BytesBuilder.create(context, names);
}
/**
* A plain null type without custom properties. This is equivalent to:
* <pre>
* nullBuilder().endNull();
* </pre>
*/
public final R nullType() {
return nullBuilder().endNull();
}
/**
* Build a null type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #nullType()}.
*/
public final NullBuilder<R> nullBuilder() {
return NullBuilder.create(context, names);
}
/** Build an Avro map type Example usage:
* <pre>
* map().values().intType()
* </pre>
* Equivalent to Avro JSON Schema:
* <pre>
* {"type":"map", "values":"int"}
* </pre>
**/
public final MapBuilder<R> map() {
return MapBuilder.create(context, names);
}
/** Build an Avro array type Example usage:
* <pre>
* array().items().longType()
* </pre>
* Equivalent to Avro JSON Schema:
* <pre>
* {"type":"array", "values":"long"}
* </pre>
**/
public final ArrayBuilder<R> array() {
return ArrayBuilder.create(context, names);
}
/** Build an Avro fixed type. Example usage:
* <pre>
* fixed("com.foo.IPv4").size(4)
* </pre>
* Equivalent to Avro JSON Schema:
* <pre>
* {"type":"fixed", "name":"com.foo.IPv4", "size":4}
* </pre>
**/
public final FixedBuilder<R> fixed(String name) {
return FixedBuilder.create(context, names, name);
}
/** Build an Avro enum type. Example usage:
* <pre>
* enumeration("Suits").namespace("org.cards").doc("card suit names")
* .symbols("HEART", "SPADE", "DIAMOND", "CLUB")
* </pre>
* Equivalent to Avro JSON Schema:
* <pre>
* {"type":"enum", "name":"Suits", "namespace":"org.cards",
* "doc":"card suit names", "symbols":[
* "HEART", "SPADE", "DIAMOND", "CLUB"]}
* </pre>
**/
public final EnumBuilder<R> enumeration(String name) {
return EnumBuilder.create(context, names, name);
}
/** Build an Avro record type. Example usage:
* <pre>
* record("com.foo.Foo").fields()
* .name("field1").typeInt().intDefault(1)
* .name("field2").typeString().noDefault()
* .name("field3").optional().typeFixed("FooFixed").size(4)
* .endRecord()
* </pre>
* Equivalent to Avro JSON Schema:
* <pre>
* {"type":"record", "name":"com.foo.Foo", "fields": [
* {"name":"field1", "type":"int", "default":1},
* {"name":"field2", "type":"string"},
* {"name":"field3", "type":[
* null, {"type":"fixed", "name":"FooFixed", "size":4}
* ]}
* ]}
* </pre>
**/
public final RecordBuilder<R> record(String name) {
return RecordBuilder.create(context, names, name);
}
/** Build an Avro union schema type. Example usage:
* <pre>unionOf().stringType().and().bytesType().endUnion()</pre>
**/
protected BaseTypeBuilder<UnionAccumulator<R>> unionOf() {
return UnionBuilder.create(context, names);
}
/** A shortcut for building a union of a type and null.
* <p/>
* For example, the code snippets below are equivalent:
* <pre>nullable().booleanType()</pre>
* <pre>unionOf().booleanType().and().nullType().endUnion()</pre>
**/
protected BaseTypeBuilder<R> nullable() {
return new BaseTypeBuilder<R>(new NullableCompletion<R>(context), names);
}
}
/** A Builder for creating any Avro schema type.
**/
public static final class TypeBuilder<R> extends BaseTypeBuilder<R> {
private TypeBuilder(Completion<R> context, NameContext names) {
super(context, names);
}
@Override
public BaseTypeBuilder<UnionAccumulator<R>> unionOf() {
return super.unionOf();
}
@Override
public BaseTypeBuilder<R> nullable() {
return super.nullable();
}
}
/** A special builder for unions. Unions cannot nest unions directly **/
private static final class UnionBuilder<R> extends
BaseTypeBuilder<UnionAccumulator<R>> {
private UnionBuilder(Completion<R> context, NameContext names) {
this(context, names, new ArrayList<Schema>());
}
private static <R> UnionBuilder<R> create(Completion<R> context, NameContext names) {
return new UnionBuilder<R>(context, names);
}
private UnionBuilder(Completion<R> context, NameContext names, List<Schema> schemas) {
super(new UnionCompletion<R>(context, names, schemas), names);
}
}
/**
* A special Builder for Record fields. The API is very similar to
* {@link BaseTypeBuilder}. However, fields have their own names, properties,
* and default values.
* <p/>
* The methods on this class create builder instances that return their
* control to the {@link FieldAssembler} of the enclosing record context after
* configuring a default for the field.
* <p/>
* For example, an int field with default value 1:
* <pre>
* intSimple().withDefault(1);
* </pre>
* or an array with items that are optional int types:
* <pre>
* array().items().optional().intType();
* </pre>
*/
public static class BaseFieldTypeBuilder<R> {
protected final FieldBuilder<R> bldr;
protected final NameContext names;
private final CompletionWrapper wrapper;
protected BaseFieldTypeBuilder(FieldBuilder<R> bldr, CompletionWrapper wrapper) {
this.bldr = bldr;
this.names = bldr.names();
this.wrapper = wrapper;
}
/**
* A plain boolean type without custom properties. This is equivalent to:
* <pre>
* booleanBuilder().endBoolean();
* </pre>
*/
public final BooleanDefault<R> booleanType() {
return booleanBuilder().endBoolean();
}
/**
* Build a boolean type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #booleanType()}.
*/
public final BooleanBuilder<BooleanDefault<R>> booleanBuilder() {
return BooleanBuilder.create(wrap(new BooleanDefault<R>(bldr)), names);
}
/**
* A plain int type without custom properties. This is equivalent to:
* <pre>
* intBuilder().endInt();
* </pre>
*/
public final IntDefault<R> intType() {
return intBuilder().endInt();
}
/**
* Build an int type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #intType()}.
*/
public final IntBuilder<IntDefault<R>> intBuilder() {
return IntBuilder.create(wrap(new IntDefault<R>(bldr)), names);
}
/**
* A plain long type without custom properties. This is equivalent to:
* <pre>
* longBuilder().endLong();
* </pre>
*/
public final LongDefault<R> longType() {
return longBuilder().endLong();
}
/**
* Build a long type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #longType()}.
*/
public final LongBuilder<LongDefault<R>> longBuilder() {
return LongBuilder.create(wrap(new LongDefault<R>(bldr)), names);
}
/**
* A plain float type without custom properties. This is equivalent to:
* <pre>
* floatBuilder().endFloat();
* </pre>
*/
public final FloatDefault<R> floatType() {
return floatBuilder().endFloat();
}
/**
* Build a float type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #floatType()}.
*/
public final FloatBuilder<FloatDefault<R>> floatBuilder() {
return FloatBuilder.create(wrap(new FloatDefault<R>(bldr)), names);
}
/**
* A plain double type without custom properties. This is equivalent to:
* <pre>
* doubleBuilder().endDouble();
* </pre>
*/
public final DoubleDefault<R> doubleType() {
return doubleBuilder().endDouble();
}
/**
* Build a double type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #doubleType()}.
*/
public final DoubleBuilder<DoubleDefault<R>> doubleBuilder() {
return DoubleBuilder.create(wrap(new DoubleDefault<R>(bldr)), names);
}
/**
* A plain string type without custom properties. This is equivalent to:
* <pre>
* stringBuilder().endString();
* </pre>
*/
public final StringDefault<R> stringType() {
return stringBuilder().endString();
}
/**
* Build a string type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #stringType()}.
*/
public final StringBldr<StringDefault<R>> stringBuilder() {
return StringBldr.create(wrap(new StringDefault<R>(bldr)), names);
}
/**
* A plain bytes type without custom properties. This is equivalent to:
* <pre>
* bytesBuilder().endBytes();
* </pre>
*/
public final BytesDefault<R> bytesType() {
return bytesBuilder().endBytes();
}
/**
* Build a bytes type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #bytesType()}.
*/
public final BytesBuilder<BytesDefault<R>> bytesBuilder() {
return BytesBuilder.create(wrap(new BytesDefault<R>(bldr)), names);
}
/**
* A plain null type without custom properties. This is equivalent to:
* <pre>
* nullBuilder().endNull();
* </pre>
*/
public final NullDefault<R> nullType() {
return nullBuilder().endNull();
}
/**
* Build a null type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #nullType()}.
*/
public final NullBuilder<NullDefault<R>> nullBuilder() {
return NullBuilder.create(wrap(new NullDefault<R>(bldr)), names);
}
/** Build an Avro map type **/
public final MapBuilder<MapDefault<R>> map() {
return MapBuilder.create(wrap(new MapDefault<R>(bldr)), names);
}
/** Build an Avro array type **/
public final ArrayBuilder<ArrayDefault<R>> array() {
return ArrayBuilder.create(wrap(new ArrayDefault<R>(bldr)), names);
}
/** Build an Avro fixed type. **/
public final FixedBuilder<FixedDefault<R>> fixed(String name) {
return FixedBuilder.create(wrap(new FixedDefault<R>(bldr)), names, name);
}
/** Build an Avro enum type. **/
public final EnumBuilder<EnumDefault<R>> enumeration(String name) {
return EnumBuilder.create(wrap(new EnumDefault<R>(bldr)), names, name);
}
/** Build an Avro record type. **/
public final RecordBuilder<RecordDefault<R>> record(String name) {
return RecordBuilder.create(wrap(new RecordDefault<R>(bldr)), names, name);
}
private <C> Completion<C> wrap(
Completion<C> completion) {
if (wrapper != null) {
return wrapper.wrap(completion);
}
return completion;
}
}
/** FieldTypeBuilder adds {@link #unionOf()}, {@link #nullable()}, and {@link #optional()}
* to BaseFieldTypeBuilder. **/
public static final class FieldTypeBuilder<R> extends BaseFieldTypeBuilder<R> {
private FieldTypeBuilder(FieldBuilder<R> bldr) {
super(bldr, null);
}
/** Build an Avro union schema type. **/
public UnionFieldTypeBuilder<R> unionOf() {
return new UnionFieldTypeBuilder<R>(bldr);
}
/**
* A shortcut for building a union of a type and null, with an optional default
* value of the non-null type.
* <p/>
* For example, the two code snippets below are equivalent:
* <pre>nullable().booleanType().booleanDefault(true)</pre>
* <pre>unionOf().booleanType().and().nullType().endUnion().booleanDefault(true)</pre>
**/
public BaseFieldTypeBuilder<R> nullable() {
return new BaseFieldTypeBuilder<R>(bldr, new NullableCompletionWrapper());
}
/**
* A shortcut for building a union of null and a type, with a null default.
* <p/>
* For example, the two code snippets below are equivalent:
* <pre>optional().booleanType()</pre>
* <pre>unionOf().nullType().and().booleanType().endUnion().nullDefault()</pre>
*/
public BaseTypeBuilder<FieldAssembler<R>> optional() {
return new BaseTypeBuilder<FieldAssembler<R>>(
new OptionalCompletion<R>(bldr), names);
}
}
/** Builder for a union field. The first type in the union corresponds
* to the possible default value type.
*/
public static final class UnionFieldTypeBuilder<R> {
private final FieldBuilder<R> bldr;
private final NameContext names;
private UnionFieldTypeBuilder(FieldBuilder<R> bldr) {
this.bldr = bldr;
this.names = bldr.names();
}
/**
* A plain boolean type without custom properties. This is equivalent to:
* <pre>
* booleanBuilder().endBoolean();
* </pre>
*/
public UnionAccumulator<BooleanDefault<R>> booleanType() {
return booleanBuilder().endBoolean();
}
/**
* Build a boolean type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #booleanType()}.
*/
public BooleanBuilder<UnionAccumulator<BooleanDefault<R>>> booleanBuilder() {
return BooleanBuilder.create(completion(new BooleanDefault<R>(bldr)), names);
}
/**
* A plain int type without custom properties. This is equivalent to:
* <pre>
* intBuilder().endInt();
* </pre>
*/
public UnionAccumulator<IntDefault<R>> intType() {
return intBuilder().endInt();
}
/**
* Build an int type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #intType()}.
*/
public IntBuilder<UnionAccumulator<IntDefault<R>>> intBuilder() {
return IntBuilder.create(completion(new IntDefault<R>(bldr)), names);
}
/**
* A plain long type without custom properties. This is equivalent to:
* <pre>
* longBuilder().endLong();
* </pre>
*/
public UnionAccumulator<LongDefault<R>> longType() {
return longBuilder().endLong();
}
/**
* Build a long type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #longType()}.
*/
public LongBuilder<UnionAccumulator<LongDefault<R>>> longBuilder() {
return LongBuilder.create(completion(new LongDefault<R>(bldr)), names);
}
/**
* A plain float type without custom properties. This is equivalent to:
* <pre>
* floatBuilder().endFloat();
* </pre>
*/
public UnionAccumulator<FloatDefault<R>> floatType() {
return floatBuilder().endFloat();
}
/**
* Build a float type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #floatType()}.
*/
public FloatBuilder<UnionAccumulator<FloatDefault<R>>> floatBuilder() {
return FloatBuilder.create(completion(new FloatDefault<R>(bldr)), names);
}
/**
* A plain double type without custom properties. This is equivalent to:
* <pre>
* doubleBuilder().endDouble();
* </pre>
*/
public UnionAccumulator<DoubleDefault<R>> doubleType() {
return doubleBuilder().endDouble();
}
/**
* Build a double type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #doubleType()}.
*/
public DoubleBuilder<UnionAccumulator<DoubleDefault<R>>> doubleBuilder() {
return DoubleBuilder.create(completion(new DoubleDefault<R>(bldr)), names);
}
/**
* A plain string type without custom properties. This is equivalent to:
* <pre>
* stringBuilder().endString();
* </pre>
*/
public UnionAccumulator<StringDefault<R>> stringType() {
return stringBuilder().endString();
}
/**
* Build a string type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #stringType()}.
*/
public StringBldr<UnionAccumulator<StringDefault<R>>> stringBuilder() {
return StringBldr.create(completion(new StringDefault<R>(bldr)), names);
}
/**
* A plain bytes type without custom properties. This is equivalent to:
* <pre>
* bytesBuilder().endBytes();
* </pre>
*/
public UnionAccumulator<BytesDefault<R>> bytesType() {
return bytesBuilder().endBytes();
}
/**
* Build a bytes type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #bytesType()}.
*/
public BytesBuilder<UnionAccumulator<BytesDefault<R>>> bytesBuilder() {
return BytesBuilder.create(completion(new BytesDefault<R>(bldr)), names);
}
/**
* A plain null type without custom properties. This is equivalent to:
* <pre>
* nullBuilder().endNull();
* </pre>
*/
public UnionAccumulator<NullDefault<R>> nullType() {
return nullBuilder().endNull();
}
/**
* Build a null type that can set custom properties. If custom properties
* are not needed it is simpler to use {@link #nullType()}.
*/
public NullBuilder<UnionAccumulator<NullDefault<R>>> nullBuilder() {
return NullBuilder.create(completion(new NullDefault<R>(bldr)), names);
}
/** Build an Avro map type **/
public MapBuilder<UnionAccumulator<MapDefault<R>>> map() {
return MapBuilder.create(completion(new MapDefault<R>(bldr)), names);
}
/** Build an Avro array type **/
public ArrayBuilder<UnionAccumulator<ArrayDefault<R>>> array() {
return ArrayBuilder.create(completion(new ArrayDefault<R>(bldr)), names);
}
/** Build an Avro fixed type. **/
public FixedBuilder<UnionAccumulator<FixedDefault<R>>> fixed(String name) {
return FixedBuilder.create(completion(new FixedDefault<R>(bldr)), names, name);
}
/** Build an Avro enum type. **/
public EnumBuilder<UnionAccumulator<EnumDefault<R>>> enumeration(String name) {
return EnumBuilder.create(completion(new EnumDefault<R>(bldr)), names, name);
}
/** Build an Avro record type. **/
public RecordBuilder<UnionAccumulator<RecordDefault<R>>> record(String name) {
return RecordBuilder.create(completion(new RecordDefault<R>(bldr)), names, name);
}
private <C> UnionCompletion<C> completion(Completion<C> context) {
return new UnionCompletion<C>(context, names, new ArrayList<Schema>());
}
}
public final static class RecordBuilder<R> extends
NamespacedBuilder<R, RecordBuilder<R>> {
private RecordBuilder(Completion<R> context, NameContext names, String name) {
super(context, names, name);
}
private static <R> RecordBuilder<R> create(Completion<R> context,
NameContext names, String name) {
return new RecordBuilder<R>(context, names, name);
}
@Override
protected RecordBuilder<R> self() {
return this;
}
public FieldAssembler<R> fields() {
Schema record = Schema.createRecord(name(), doc(), space(), false);
// place the record in the name context, fields yet to be set.
completeSchema(record);
return new FieldAssembler<R>(
context(), names().namespace(record.getNamespace()), record);
}
}
public final static class FieldAssembler<R> {
private final List<Field> fields = new ArrayList<Field>();
private final Completion<R> context;
private final NameContext names;
private final Schema record;
private FieldAssembler(Completion<R> context, NameContext names, Schema record) {
this.context = context;
this.names = names;
this.record = record;
}
/**
* Add a field with the given name.
* @return A {@link FieldBuilder} for the given name.
*/
public FieldBuilder<R> name(String fieldName) {
return new FieldBuilder<R>(this, names, fieldName);
}
/**
* Shortcut for creating a boolean field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().booleanType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredBoolean(String fieldName) {
return name(fieldName).type().booleanType().noDefault();
}
/**
* Shortcut for creating an optional boolean field: a union of null and
* boolean with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().booleanType()
* </pre>
*/
public FieldAssembler<R> optionalBoolean(String fieldName) {
return name(fieldName).type().optional().booleanType();
}
/**
* Shortcut for creating a nullable boolean field: a union of boolean and
* null with an boolean default.
* <p/>
* This is equivalent to:
*
* <pre>
* name(fieldName).type().nullable().booleanType().booleanDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableBoolean(String fieldName, boolean defaultVal) {
return name(fieldName)
.type().nullable().booleanType().booleanDefault(defaultVal);
}
/**
* Shortcut for creating an int field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().intType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredInt(String fieldName) {
return name(fieldName).type().intType().noDefault();
}
/**
* Shortcut for creating an optional int field: a union of null and int
* with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().intType()
* </pre>
*/
public FieldAssembler<R> optionalInt(String fieldName) {
return name(fieldName).type().optional().intType();
}
/**
* Shortcut for creating a nullable int field: a union of int and null
* with an int default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().nullable().intType().intDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableInt(String fieldName, int defaultVal) {
return name(fieldName).type().nullable().intType().intDefault(defaultVal);
}
/**
* Shortcut for creating a long field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().longType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredLong(String fieldName) {
return name(fieldName).type().longType().noDefault();
}
/**
* Shortcut for creating an optional long field: a union of null and long
* with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().longType()
* </pre>
*/
public FieldAssembler<R> optionalLong(String fieldName) {
return name(fieldName).type().optional().longType();
}
/**
* Shortcut for creating a nullable long field: a union of long and null
* with a long default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().nullable().longType().longDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableLong(String fieldName, long defaultVal) {
return name(fieldName).type().nullable().longType().longDefault(defaultVal);
}
/**
* Shortcut for creating a float field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().floatType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredFloat(String fieldName) {
return name(fieldName).type().floatType().noDefault();
}
/**
* Shortcut for creating an optional float field: a union of null and float
* with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().floatType()
* </pre>
*/
public FieldAssembler<R> optionalFloat(String fieldName) {
return name(fieldName).type().optional().floatType();
}
/**
* Shortcut for creating a nullable float field: a union of float and null
* with a float default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().nullable().floatType().floatDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableFloat(String fieldName, float defaultVal) {
return name(fieldName).type().nullable().floatType().floatDefault(defaultVal);
}
/**
* Shortcut for creating a double field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().doubleType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredDouble(String fieldName) {
return name(fieldName).type().doubleType().noDefault();
}
/**
* Shortcut for creating an optional double field: a union of null and double
* with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().doubleType()
* </pre>
*/
public FieldAssembler<R> optionalDouble(String fieldName) {
return name(fieldName).type().optional().doubleType();
}
/**
* Shortcut for creating a nullable double field: a union of double and null
* with a double default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().nullable().doubleType().doubleDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableDouble(String fieldName, double defaultVal) {
return name(fieldName).type().nullable().doubleType().doubleDefault(defaultVal);
}
/**
* Shortcut for creating a string field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().stringType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredString(String fieldName) {
return name(fieldName).type().stringType().noDefault();
}
/**
* Shortcut for creating an optional string field: a union of null and string
* with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().stringType()
* </pre>
*/
public FieldAssembler<R> optionalString(String fieldName) {
return name(fieldName).type().optional().stringType();
}
/**
* Shortcut for creating a nullable string field: a union of string and null
* with a string default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().nullable().stringType().stringDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableString(String fieldName, String defaultVal) {
return name(fieldName).type().nullable().stringType().stringDefault(defaultVal);
}
/**
* Shortcut for creating a bytes field with the given name and no default.
* <p/>This is equivalent to:
* <pre>
* name(fieldName).type().bytesType().noDefault()
* </pre>
*/
public FieldAssembler<R> requiredBytes(String fieldName) {
return name(fieldName).type().bytesType().noDefault();
}
/**
* Shortcut for creating an optional bytes field: a union of null and bytes
* with null default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().optional().bytesType()
* </pre>
*/
public FieldAssembler<R> optionalBytes(String fieldName) {
return name(fieldName).type().optional().bytesType();
}
/**
* Shortcut for creating a nullable bytes field: a union of bytes and null
* with a bytes default.<p/>
* This is equivalent to:
* <pre>
* name(fieldName).type().nullable().bytesType().bytesDefault(defaultVal)
* </pre>
*/
public FieldAssembler<R> nullableBytes(String fieldName, byte[] defaultVal) {
return name(fieldName).type().nullable().bytesType().bytesDefault(defaultVal);
}
/**
* End adding fields to this record, returning control
* to the context that this record builder was created in.
*/
public R endRecord() {
record.setFields(fields);
return context.complete(record);
}
private FieldAssembler<R> addField(Field field) {
fields.add(field);
return this;
}
}
/**
* Builds a Field in the context of a {@link FieldAssembler}.
*
* Usage is to first configure any of the optional parameters and then to call one
* of the type methods to complete the field. For example
* <pre>
* .namespace("org.apache.example").orderDecending().type()
* </pre>
* Optional parameters for a field are namespace, doc, order, and aliases.
*/
public final static class FieldBuilder<R> extends
NamedBuilder<FieldBuilder<R>> {
private final FieldAssembler<R> fields;
private Schema.Field.Order order = Schema.Field.Order.ASCENDING;
private FieldBuilder(FieldAssembler<R> fields, NameContext names, String name) {
super(names, name);
this.fields = fields;
}
/** Set this field to have ascending order. Ascending is the default **/
public FieldBuilder<R> orderAscending() {
order = Schema.Field.Order.ASCENDING;
return self();
}
/** Set this field to have decending order. Decending is the default **/
public FieldBuilder<R> orderDescending() {
order = Schema.Field.Order.DESCENDING;
return self();
}
/** Set this field to ignore order. **/
public FieldBuilder<R> orderIgnore() {
order = Schema.Field.Order.IGNORE;
return self();
}
/**
* Final step in configuring this field, finalizing name, namespace, alias,
* and order.
* @return A builder for the field's type and default value.
*/
public FieldTypeBuilder<R> type() {
return new FieldTypeBuilder<R>(this);
}
/**
* Final step in configuring this field, finalizing name, namespace, alias,
* and order. Sets the field's type to the provided schema, returns a
* {@link GenericDefault}.
*/
public GenericDefault<R> type(Schema type) {
return new GenericDefault<R>(this, type);
}
/**
* Final step in configuring this field, finalizing name, namespace, alias,
* and order. Sets the field's type to the schema by name reference.
* <p/>
* The name must correspond with a named schema that has already been
* created in the context of this builder. The name may be a fully qualified
* name, or a short name. If it is a short name, the namespace context of
* this builder will be used.
* <p/>
* The name and namespace context rules are the same as the Avro schema JSON
* specification.
*/
public GenericDefault<R> type(String name) {
return type(name, null);
}
/**
* Final step in configuring this field, finalizing name, namespace, alias,
* and order. Sets the field's type to the schema by name reference.
* <p/>
* The name must correspond with a named schema that has already been
* created in the context of this builder. The name may be a fully qualified
* name, or a short name. If it is a full name, the namespace is ignored. If
* it is a short name, the namespace provided is used. If the namespace
* provided is null, the namespace context of this builder will be used.
* <p/>
* The name and namespace context rules are the same as the Avro schema JSON
* specification.
*/
public GenericDefault<R> type(String name, String namespace) {
Schema schema = names().get(name, namespace);
return type(schema);
}
private FieldAssembler<R> completeField(Schema schema, Object defaultVal) {
JsonNode defaultNode = toJsonNode(defaultVal);
return completeField(schema, defaultNode);
}
private FieldAssembler<R> completeField(Schema schema) {
return completeField(schema, null);
}
private FieldAssembler<R> completeField(Schema schema, JsonNode defaultVal) {
Field field = new Field(name(), schema, doc(), defaultVal, order);
addPropsTo(field);
addAliasesTo(field);
return fields.addField(field);
}
@Override
protected FieldBuilder<R> self() {
return this;
}
}
/** Abstract base class for field defaults. **/
public static abstract class FieldDefault<R, S extends FieldDefault<R, S>> extends Completion<S> {
private final FieldBuilder<R> field;
private Schema schema;
FieldDefault(FieldBuilder<R> field) {
this.field = field;
}
/** Completes this field with no default value **/
public final FieldAssembler<R> noDefault() {
return field.completeField(schema);
}
private FieldAssembler<R> usingDefault(Object defaultVal) {
return field.completeField(schema, defaultVal);
}
@Override
final S complete(Schema schema) {
this.schema = schema;
return self();
}
abstract S self();
}
/** Choose whether to use a default value for the field or not. **/
public static class BooleanDefault<R> extends FieldDefault<R, BooleanDefault<R>> {
private BooleanDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided **/
public final FieldAssembler<R> booleanDefault(boolean defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final BooleanDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class IntDefault<R> extends FieldDefault<R, IntDefault<R>> {
private IntDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided **/
public final FieldAssembler<R> intDefault(int defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final IntDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class LongDefault<R> extends FieldDefault<R, LongDefault<R>> {
private LongDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided **/
public final FieldAssembler<R> longDefault(long defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final LongDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class FloatDefault<R> extends FieldDefault<R, FloatDefault<R>> {
private FloatDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided **/
public final FieldAssembler<R> floatDefault(float defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final FloatDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class DoubleDefault<R> extends FieldDefault<R, DoubleDefault<R>> {
private DoubleDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided **/
public final FieldAssembler<R> doubleDefault(double defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final DoubleDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class StringDefault<R> extends FieldDefault<R, StringDefault<R>> {
private StringDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided. Cannot be null. **/
public final FieldAssembler<R> stringDefault(String defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final StringDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class BytesDefault<R> extends FieldDefault<R, BytesDefault<R>> {
private BytesDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided, cannot be null **/
public final FieldAssembler<R> bytesDefault(byte[] defaultVal) {
return super.usingDefault(ByteBuffer.wrap(defaultVal));
}
/** Completes this field with the default value provided, cannot be null **/
public final FieldAssembler<R> bytesDefault(ByteBuffer defaultVal) {
return super.usingDefault(defaultVal);
}
/** Completes this field with the default value provided, cannot be null.
* The string is interpreted as a byte[], with each character code point
* value equalling the byte value, as in the Avro spec JSON default. **/
public final FieldAssembler<R> bytesDefault(String defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final BytesDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class NullDefault<R> extends FieldDefault<R, NullDefault<R>> {
private NullDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with a default value of null **/
public final FieldAssembler<R> nullDefault() {
return super.usingDefault(null);
}
@Override
final NullDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class MapDefault<R> extends FieldDefault<R, MapDefault<R>> {
private MapDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided, cannot be null **/
public final <K, V> FieldAssembler<R> mapDefault(Map<K, V> defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final MapDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class ArrayDefault<R> extends FieldDefault<R, ArrayDefault<R>> {
private ArrayDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided, cannot be null **/
public final <V> FieldAssembler<R> arrayDefault(List<V> defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final ArrayDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class FixedDefault<R> extends FieldDefault<R, FixedDefault<R>> {
private FixedDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided, cannot be null **/
public final FieldAssembler<R> fixedDefault(byte[] defaultVal) {
return super.usingDefault(ByteBuffer.wrap(defaultVal));
}
/** Completes this field with the default value provided, cannot be null **/
public final FieldAssembler<R> fixedDefault(ByteBuffer defaultVal) {
return super.usingDefault(defaultVal);
}
/** Completes this field with the default value provided, cannot be null.
* The string is interpreted as a byte[], with each character code point
* value equalling the byte value, as in the Avro spec JSON default. **/
public final FieldAssembler<R> fixedDefault(String defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final FixedDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class EnumDefault<R> extends FieldDefault<R, EnumDefault<R>> {
private EnumDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided, cannot be null **/
public final FieldAssembler<R> enumDefault(String defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final EnumDefault<R> self() {
return this;
}
}
/** Choose whether to use a default value for the field or not. **/
public static class RecordDefault<R> extends FieldDefault<R, RecordDefault<R>> {
private RecordDefault(FieldBuilder<R> field) {
super(field);
}
/** Completes this field with the default value provided, cannot be null **/
public final FieldAssembler<R> recordDefault(GenericRecord defaultVal) {
return super.usingDefault(defaultVal);
}
@Override
final RecordDefault<R> self() {
return this;
}
}
public final static class GenericDefault<R> {
private final FieldBuilder<R> field;
private final Schema schema;
private GenericDefault(FieldBuilder<R> field, Schema schema) {
this.field = field;
this.schema = schema;
}
/** Do not use a default value for this field. **/
public FieldAssembler<R> noDefault() {
return field.completeField(schema);
}
/** Completes this field with the default value provided.
* The value must conform to the schema of the field. **/
public FieldAssembler<R> withDefault(Object defaultVal) {
return field.completeField(schema, defaultVal);
}
}
/**
* Completion<R> is for internal builder use, all subclasses are private.
*
* Completion is an object that takes a Schema and returns some result.
*/
private abstract static class Completion<R> {
abstract R complete(Schema schema);
}
private static class SchemaCompletion extends Completion<Schema> {
@Override
protected Schema complete(Schema schema) {
return schema;
}
}
private static final Schema NULL_SCHEMA = Schema.create(Schema.Type.NULL);
private static class NullableCompletion<R> extends Completion<R> {
private final Completion<R> context;
private NullableCompletion(Completion<R> context) {
this.context = context;
}
@Override
protected R complete(Schema schema) {
// wrap the schema as a union of the schema and null
Schema nullable = Schema.createUnion(Arrays.asList(schema, NULL_SCHEMA));
return context.complete(nullable);
}
}
private static class OptionalCompletion<R> extends Completion<FieldAssembler<R>> {
private final FieldBuilder<R> bldr;
public OptionalCompletion(FieldBuilder<R> bldr) {
this.bldr = bldr;
}
@Override
protected FieldAssembler<R> complete(Schema schema) {
// wrap the schema as a union of null and the schema
Schema optional = Schema.createUnion(Arrays.asList(NULL_SCHEMA, schema));
return bldr.completeField(optional, (Object)null);
}
}
private abstract static class CompletionWrapper {
abstract <R> Completion<R> wrap(Completion<R> completion);
}
private static final class NullableCompletionWrapper extends CompletionWrapper {
@Override
<R> Completion<R> wrap(Completion<R> completion) {
return new NullableCompletion<R>(completion);
}
}
private static abstract class NestedCompletion<R> extends Completion<R> {
private final Completion<R> context;
private final PropBuilder<?> assembler;
private NestedCompletion(PropBuilder<?> assembler, Completion<R> context) {
this.context = context;
this.assembler = assembler;
}
@Override
protected final R complete(Schema schema) {
Schema outer = outerSchema(schema);
assembler.addPropsTo(outer);
return context.complete(outer);
}
protected abstract Schema outerSchema(Schema inner);
}
private static class MapCompletion<R> extends NestedCompletion<R> {
private MapCompletion(MapBuilder<R> assembler, Completion<R> context) {
super(assembler, context);
}
@Override
protected Schema outerSchema(Schema inner) {
return Schema.createMap(inner);
}
}
private static class ArrayCompletion<R> extends NestedCompletion<R> {
private ArrayCompletion(ArrayBuilder<R> assembler, Completion<R> context) {
super(assembler, context);
}
@Override
protected Schema outerSchema(Schema inner) {
return Schema.createArray(inner);
}
}
private static class UnionCompletion<R> extends
Completion<UnionAccumulator<R>> {
private final Completion<R> context;
private final NameContext names;
private final List<Schema> schemas;
private UnionCompletion(Completion<R> context, NameContext names, List<Schema> schemas) {
this.context = context;
this.names = names;
this.schemas = schemas;
}
@Override
protected UnionAccumulator<R> complete(Schema schema) {
List<Schema> updated = new ArrayList<Schema>(this.schemas);
updated.add(schema);
return new UnionAccumulator<R>(context, names, updated);
}
}
/** Accumulates all of the types in a union. Add an additional type with
* {@link #and()}. Complete the union with {@link #endUnion()}
*/
public static final class UnionAccumulator<R> {
private final Completion<R> context;
private final NameContext names;
private final List<Schema> schemas;
private UnionAccumulator(Completion<R> context, NameContext names, List<Schema> schemas) {
this.context = context;
this.names = names;
this.schemas = schemas;
}
/** Add an additional type to this union **/
public BaseTypeBuilder<UnionAccumulator<R>> and() {
return new UnionBuilder<R>(context, names, schemas);
}
/** Complete this union **/
public R endUnion() {
Schema schema = Schema.createUnion(schemas);
return context.complete(schema);
}
}
private static void checkRequired(Object reference, String errorMessage) {
if (reference == null) {
throw new NullPointerException(errorMessage);
}
}
// create default value JsonNodes from objects
private static JsonNode toJsonNode(Object o) {
try {
String s;
if (o instanceof ByteBuffer) {
// special case since GenericData.toString() is incorrect for bytes
// note that this does not handle the case of a default value with nested bytes
ByteBuffer bytes = ((ByteBuffer) o);
bytes.mark();
byte[] data = new byte[bytes.remaining()];
bytes.get(data);
bytes.reset(); // put the buffer back the way we got it
s = new String(data, "ISO-8859-1");
char[] quoted = JsonStringEncoder.getInstance().quoteAsString(s);
s = "\"" + new String(quoted) + "\"";
} else {
s = GenericData.get().toString(o);
}
return new ObjectMapper().readTree(s);
} catch (IOException e) {
throw new SchemaBuilderException(e);
}
}
}