/**
* Copyright (C) cedarsoft GmbH.
*
* Licensed under the GNU General Public License version 3 (the "License")
* with Classpath Exception; you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.cedarsoft.org/gpl3ce
* (GPL 3 with Classpath Exception)
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 only, as
* published by the Free Software Foundation. cedarsoft GmbH designates this
* particular file as subject to the "Classpath" exception as provided
* by cedarsoft GmbH in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 3 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 3 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact cedarsoft GmbH, 72810 Gomaringen, Germany,
* or visit www.cedarsoft.com if you need additional information or
* have any questions.
*/
package com.cedarsoft.serialization.jackson;
import com.cedarsoft.serialization.AbstractStreamSerializer;
import com.cedarsoft.version.Version;
import com.cedarsoft.version.VersionException;
import com.cedarsoft.version.VersionRange;
import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.JsonToken;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.WillNotClose;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
/**
* @param <T> the type
* @author Johannes Schneider (<a href="mailto:js@cedarsoft.com">js@cedarsoft.com</a>)
*/
public abstract class AbstractJacksonSerializer<T> extends AbstractStreamSerializer<T, JsonGenerator, JsonParser, JsonProcessingException> implements JacksonSerializer<T> {
public static final String FIELD_NAME_DEFAULT_TEXT = "$";
public static final String PROPERTY_TYPE = "@type";
public static final String PROPERTY_VERSION = "@version";
public static final String PROPERTY_SUB_TYPE = "@subtype";
@Nonnull
private final String type; //$NON-NLS-1$
protected AbstractJacksonSerializer( @Nonnull String type, @Nonnull VersionRange formatVersionRange ) {
super( formatVersionRange );
this.type = type;
}
@Nonnull
@Override
public String getType() {
return type;
}
@Override
public void verifyType( @Nullable String type ) throws InvalidTypeException {
if ( !this.type.equals( type ) ) {//$NON-NLS-1$
throw new InvalidTypeException( type, this.type );
}
}
@Override
public void serialize( @Nonnull T object, @WillNotClose @Nonnull OutputStream out ) throws IOException {
JsonFactory jsonFactory = JacksonSupport.getJsonFactory();
JsonGenerator generator = jsonFactory.createGenerator( out, JsonEncoding.UTF8 );
serialize( object, generator );
generator.flush();
}
/**
* Serializes the object to the given serializeTo.
* <p>
* The serializer is responsible for writing start/close object/array brackets if necessary.
* This method also writes the @type property.
*
* @param object the object that is serialized
* @param generator the serialize to object
* @throws java.io.IOException if there is an io problem
*/
@Override
public void serialize( @Nonnull T object, @Nonnull JsonGenerator generator ) throws IOException {
if ( isObjectType() ) {
generator.writeStartObject();
beforeTypeAndVersion( object, generator );
writeTypeAndVersion( generator );
}
serialize( generator, object, getFormatVersion() );
if ( isObjectType() ) {
generator.writeEndObject();
}
}
protected void writeTypeAndVersion( @Nonnull JsonGenerator generator ) throws IOException {
generator.writeStringField( PROPERTY_TYPE, type );
generator.writeStringField( PROPERTY_VERSION, getFormatVersion().format() );
}
protected void beforeTypeAndVersion( @Nonnull T object, @Nonnull JsonGenerator serializeTo ) throws IOException {
}
@Nonnull
@Override
public T deserialize( @Nonnull InputStream in ) throws IOException, VersionException {
return deserialize( in, null );
}
@Override
@Nonnull
public T deserialize( @Nonnull JsonParser parser ) throws IOException, JsonProcessingException, InvalidTypeException {
return deserializeInternal( parser, null );
}
@Nonnull
public T deserialize( @Nonnull InputStream in, @Nullable Version version ) throws IOException, VersionException {
try {
JsonFactory jsonFactory = JacksonSupport.getJsonFactory();
JsonParser parser = createJsonParser( jsonFactory, in );
T deserialized = deserializeInternal( parser, version );
JacksonParserWrapper parserWrapper = new JacksonParserWrapper( parser );
if ( parserWrapper.nextToken() != null ) {
throw new JsonParseException( "No consumed everything " + parserWrapper.getCurrentToken(), parserWrapper.getCurrentLocation() );
}
parserWrapper.close();
return deserialized;
} catch ( InvalidTypeException e ) {
throw new IOException( "Could not parse due to " + e.getMessage(), e );
}
}
/**
* This method creates the parser. This method may be overridden to create a FilteringJsonParser or something like that
* @param jsonFactory the json factory
* @param in the input stream
* @return the created json parser
* @throws java.io.IOException if there is an io problem
*/
@Nonnull
protected JsonParser createJsonParser( @Nonnull JsonFactory jsonFactory, @Nonnull InputStream in ) throws IOException {
return jsonFactory.createParser( in );
}
/**
* If the format version override is not null, the type and version field are skipped
* @param parser the parser
* @param formatVersionOverride the format version override (usually "null")
* @return the deserialized object
* @throws java.io.IOException if there is an io problem
* @throws com.cedarsoft.serialization.jackson.InvalidTypeException if the type is invalid
*/
@Nonnull
protected T deserializeInternal( @Nonnull JsonParser parser, @Nullable Version formatVersionOverride ) throws IOException, JsonProcessingException, InvalidTypeException {
JacksonParserWrapper parserWrapper = new JacksonParserWrapper( parser );
Version version = prepareDeserialization( parserWrapper, formatVersionOverride );
T deserialized = deserialize( parser, version );
if ( isObjectType() ) {
if ( parserWrapper.getCurrentToken() != JsonToken.END_OBJECT ) {
throw new JsonParseException( "No consumed everything " + parserWrapper.getCurrentToken(), parserWrapper.getCurrentLocation() );
}
}
return deserialized;
}
/**
* Prepares the deserialization.
*
* If the format version is set - the type and version properties are *not* read!
* This can be useful for cases where this information is not available...
*
* @param wrapper the wrapper
* @param formatVersionOverride the format version
* @return the format version
* @throws java.io.IOException if there is an io problem
* @throws com.cedarsoft.serialization.jackson.InvalidTypeException if the type is invalid
*/
@Nonnull
protected Version prepareDeserialization( @Nonnull JacksonParserWrapper wrapper, @Nullable Version formatVersionOverride ) throws IOException, InvalidTypeException {
if ( isObjectType() ) {
wrapper.nextToken( JsonToken.START_OBJECT );
beforeTypeAndVersion( wrapper );
if ( formatVersionOverride == null ) {
wrapper.nextFieldValue( PROPERTY_TYPE );
String readType = wrapper.getText();
verifyType( readType );
wrapper.nextFieldValue( PROPERTY_VERSION );
Version version = Version.parse( wrapper.getText() );
verifyVersionReadable( version );
return version;
} else {
verifyVersionReadable( formatVersionOverride );
return formatVersionOverride;
}
} else {
//Not an object type
wrapper.nextToken();
return getFormatVersion();
}
}
/**
* Callback method that is called before the type and version are parsed
*
* @param wrapper the wrapper
* @throws java.io.IOException if there is an io exception
* @throws com.cedarsoft.serialization.jackson.InvalidTypeException if the type is invalid
*/
protected void beforeTypeAndVersion( @Nonnull JacksonParserWrapper wrapper ) throws IOException, JsonProcessingException, InvalidTypeException {
}
protected <T> void serializeArray( @Nonnull Iterable<? extends T> elements, @Nonnull Class<T> type, @Nonnull JsonGenerator serializeTo, @Nonnull Version formatVersion ) throws IOException {
serializeArray( elements, type, null, serializeTo, formatVersion );
}
protected <T> void serializeArray( @Nonnull Iterable<? extends T> elements, @Nonnull Class<T> type, @Nullable String propertyName, @Nonnull JsonGenerator serializeTo, @Nonnull Version formatVersion ) throws IOException {
JacksonSerializer<? super T> serializer = getSerializer( type );
Version delegateVersion = delegatesMappings.getVersionMappings().resolveVersion( type, formatVersion );
if ( propertyName == null ) {
serializeTo.writeStartArray();
} else {
serializeTo.writeArrayFieldStart( propertyName );
}
for ( T element : elements ) {
if ( serializer.isObjectType() ) {
serializeTo.writeStartObject();
}
serializer.serialize( serializeTo, element, delegateVersion );
if ( serializer.isObjectType() ) {
serializeTo.writeEndObject();
}
}
serializeTo.writeEndArray();
}
@Nonnull
protected <T> List<? extends T> deserializeArray( @Nonnull Class<T> type, @Nonnull JsonParser deserializeFrom, @Nonnull Version formatVersion ) throws IOException {
return deserializeArray( type, null, deserializeFrom, formatVersion );
}
@Nonnull
protected <T> List<? extends T> deserializeArray( @Nonnull Class<T> type, @Nullable String propertyName, @Nonnull JsonParser deserializeFrom, @Nonnull Version formatVersion ) throws IOException {
JacksonParserWrapper parserWrapper = new JacksonParserWrapper( deserializeFrom );
if ( propertyName == null ) {
parserWrapper.verifyCurrentToken( JsonToken.START_ARRAY );
} else {
parserWrapper.nextToken();
parserWrapper.verifyCurrentToken( JsonToken.FIELD_NAME );
String currentName = parserWrapper.getCurrentName();
if ( !propertyName.equals( currentName ) ) {
throw new JsonParseException( "Invalid field. Expected <" + propertyName + "> but was <" + currentName + ">", parserWrapper.getCurrentLocation() );
}
parserWrapper.nextToken();
}
List<T> deserialized = new ArrayList<T>();
while ( deserializeFrom.nextToken() != JsonToken.END_ARRAY ) {
deserialized.add( deserialize( type, formatVersion, deserializeFrom ) );
}
return deserialized;
}
public <T> void serialize( @Nullable T object, @Nonnull Class<T> type, @Nonnull String propertyName, @Nonnull JsonGenerator serializeTo, @Nonnull Version formatVersion ) throws JsonProcessingException, IOException {
serializeTo.writeFieldName( propertyName );
//Fast exit if the value is null
if ( object == null ) {
serializeTo.writeNull();
return;
}
JacksonSerializer<? super T> serializer = getSerializer( type );
Version delegateVersion = delegatesMappings.getVersionMappings().resolveVersion( type, formatVersion );
if ( serializer.isObjectType() ) {
serializeTo.writeStartObject();
}
serializer.serialize( serializeTo, object, delegateVersion );
if ( serializer.isObjectType() ) {
serializeTo.writeEndObject();
}
}
@Nullable
protected <T> T deserializeNullable( @Nonnull Class<T> type, @Nonnull String propertyName, @Nonnull Version formatVersion, @Nonnull JsonParser deserializeFrom ) throws IOException, JsonProcessingException {
JacksonParserWrapper parserWrapper = new JacksonParserWrapper( deserializeFrom );
parserWrapper.nextFieldValue( propertyName );
if ( parserWrapper.getCurrentToken() == JsonToken.VALUE_NULL ) {
return null;
}
return deserialize( type, formatVersion, deserializeFrom );
}
@Nonnull
protected <T> T deserialize( @Nonnull Class<T> type, @Nonnull String propertyName, @Nonnull Version formatVersion, @Nonnull JsonParser deserializeFrom ) throws IOException, JsonProcessingException {
JacksonParserWrapper parserWrapper = new JacksonParserWrapper( deserializeFrom );
parserWrapper.nextToken();
parserWrapper.verifyCurrentToken( JsonToken.FIELD_NAME );
String currentName = parserWrapper.getCurrentName();
if ( !propertyName.equals( currentName ) ) {
throw new JsonParseException( "Invalid field. Expected <" + propertyName + "> but was <" + currentName + ">", parserWrapper.getCurrentLocation() );
}
parserWrapper.nextToken();
return deserialize( type, formatVersion, deserializeFrom );
}
@Nonnull
@Override
public <T> JacksonSerializer<? super T> getSerializer( @Nonnull Class<T> type ) {
return ( JacksonSerializer<? super T> ) super.getSerializer( type );
}
@Override
public boolean isObjectType() {
return true;
}
public void serializeEnum( @Nonnull Enum<?> enumValue, @Nonnull String propertyName, @Nonnull JsonGenerator serializeTo ) throws IOException {
serializeTo.writeStringField( propertyName, enumValue.name() );
}
@Nonnull
public <T extends Enum<T>> T deserializeEnum( @Nonnull Class<T> enumClass, @Nonnull String propertyName, @Nonnull JacksonParserWrapper parser ) throws IOException {
parser.nextFieldValue( propertyName );
return Enum.valueOf( enumClass, parser.getText() );
}
}