/*
* Copyright (c) 2012, Paul Merlin. All Rights Reserved.
*
* Licensed 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.qi4j.valueserialization.jackson;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.MappingJsonFactory;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import java.io.InputStream;
import java.util.Collection;
import java.util.Map;
import org.qi4j.api.injection.scope.Service;
import org.qi4j.api.injection.scope.Structure;
import org.qi4j.api.service.ServiceReference;
import org.qi4j.api.structure.Application;
import org.qi4j.api.structure.Module;
import org.qi4j.api.type.ValueType;
import org.qi4j.api.value.ValueDeserializer;
import org.qi4j.api.value.ValueSerializationException;
import org.qi4j.functional.Function;
import org.qi4j.spi.value.ValueDeserializerAdapter;
/**
* ValueDeserializer reading Values from JSON documents using Jackson.
*/
public class JacksonValueDeserializer
extends ValueDeserializerAdapter<JsonParser, JsonNode>
{
private final JsonFactory jsonFactory = new MappingJsonFactory();
public JacksonValueDeserializer( @Structure Application application,
@Structure Module module,
@Service ServiceReference<ValueDeserializer> serviceRef )
{
super( application, module, serviceRef );
}
@Override
protected JsonParser adaptInput( InputStream input )
throws Exception
{
return jsonFactory.createParser( input );
}
@Override
protected void onDeserializationEnd( ValueType valueType, JsonParser input )
throws Exception
{
input.close();
}
@Override
protected Object readPlainValue( JsonParser input )
throws Exception
{
JsonNode jsonNode = input.readValueAsTree();
if( jsonNode.isArray() || jsonNode.isObject() )
{
throw new ValueSerializationException( "Asked for a Value but found an Object or an Array at "
+ input.getCurrentLocation().toString() );
}
if( jsonNode.isDouble() )
{
return jsonNode.asDouble();
}
if( jsonNode.isLong() )
{
return jsonNode.asLong();
}
if( jsonNode.isInt() )
{
return jsonNode.asInt();
}
if( jsonNode.isBoolean() )
{
return jsonNode.asBoolean();
}
if( jsonNode.isNull() )
{
return null;
}
return jsonNode.asText();
}
@Override
protected <T> Collection<T> readArrayInCollection( JsonParser input,
Function<JsonParser, T> deserializer,
Collection<T> collection )
throws Exception
{
JsonToken token = input.getCurrentToken();
if( token == JsonToken.VALUE_NULL )
{
return null;
}
if( token != JsonToken.START_ARRAY )
{
token = input.nextToken();
}
if( token == JsonToken.VALUE_NULL )
{
return null;
}
if( token != JsonToken.START_ARRAY )
{
throw new ValueSerializationException( "Expected an array start at "
+ input.getCurrentLocation().toString() );
}
while( input.nextToken() != JsonToken.END_ARRAY )
{
T element = deserializer.map( input );
collection.add( element );
}
return collection;
}
@Override
protected <K, V> Map<K, V> readMapInMap( JsonParser input,
Function<JsonParser, K> keyDeserializer,
Function<JsonParser, V> valueDeserializer,
Map<K, V> map )
throws Exception
{
JsonToken token = input.getCurrentToken();
if( token == JsonToken.VALUE_NULL )
{
return null;
}
if( token != JsonToken.START_ARRAY )
{
token = input.nextToken();
}
if( token == JsonToken.VALUE_NULL )
{
return null;
}
if( token != JsonToken.START_ARRAY )
{
throw new ValueSerializationException( "Expected an array start at "
+ input.getCurrentLocation().toString() );
}
JsonToken currentToken = input.nextToken();
while( currentToken != JsonToken.END_ARRAY )
{
if( currentToken != JsonToken.START_OBJECT )
{
throw new ValueSerializationException( "Expected an object start at "
+ input.getCurrentLocation().toString() );
}
currentToken = input.nextToken();
K key = null;
V value = null;
while( currentToken != JsonToken.END_OBJECT )
{
String objectKey = input.getCurrentName();
input.nextToken();
if( "key".equals( objectKey ) )
{
key = keyDeserializer.map( input );
}
else if( "value".equals( objectKey ) )
{
value = valueDeserializer.map( input );
}
else
{
//input.nextToken();
input.skipChildren();
}
currentToken = input.nextToken();
}
if( key != null )
{
map.put( key, value );
}
currentToken = input.nextToken();
}
return map;
}
@Override
protected ObjectNode readObjectTree( JsonParser input )
throws Exception
{
JsonToken token = input.getCurrentToken();
if( token == JsonToken.VALUE_NULL )
{
return null;
}
if( token != JsonToken.START_OBJECT )
{
token = input.nextToken();
}
if( token != JsonToken.START_OBJECT )
{
throw new ValueSerializationException( "Expected an object start at "
+ input.getCurrentLocation().toString() );
}
return (ObjectNode) input.readValueAsTree();
}
@Override
protected Object asSimpleValue( JsonNode inputNode )
throws Exception
{
if( isNullOrMissing( inputNode ) )
{
return null;
}
if( !inputNode.isValueNode() )
{
throw new ValueSerializationException( "Expected a value node but got a container node " + inputNode );
}
if( inputNode.isDouble() )
{
return inputNode.asDouble();
}
if( inputNode.isLong() )
{
return inputNode.asLong();
}
if( inputNode.isInt() )
{
return inputNode.asInt();
}
if( inputNode.isBoolean() )
{
return inputNode.asBoolean();
}
return inputNode.asText();
}
@Override
protected boolean isObjectValue( JsonNode inputNode )
throws Exception
{
if( isNullOrMissing( inputNode ) )
{
return false;
}
return inputNode.isObject();
}
@Override
protected boolean objectHasField( JsonNode inputNode, String key )
throws Exception
{
if( isNullOrMissing( inputNode ) )
{
return false;
}
if( !inputNode.isObject() )
{
throw new ValueSerializationException( "Expected an object but got " + inputNode );
}
return inputNode.has( key );
}
@Override
protected <T> T getObjectFieldValue( JsonNode inputNode, String key, Function<JsonNode, T> valueDeserializer )
throws Exception
{
JsonNode valueNode = inputNode.get( key );
if( isNullOrMissing( valueNode ) )
{
return null;
}
T value = valueDeserializer.map( valueNode );
return value;
}
@Override
protected <T> void putArrayNodeInCollection( JsonNode inputNode,
Function<JsonNode, T> deserializer,
Collection<T> collection )
throws Exception
{
if( isNullOrMissing( inputNode ) )
{
return;
}
if( !inputNode.isArray() )
{
throw new ValueSerializationException( "Expected an array but got " + inputNode );
}
ArrayNode array = (ArrayNode) inputNode;
for( JsonNode item : array )
{
T value = deserializer.map( item );
collection.add( value );
}
}
@Override
protected <K, V> void putArrayNodeInMap( JsonNode inputNode,
Function<JsonNode, K> keyDeserializer,
Function<JsonNode, V> valueDeserializer,
Map<K, V> map )
throws Exception
{
if( isNullOrMissing( inputNode ) )
{
return;
}
if( !inputNode.isArray() )
{
throw new ValueSerializationException( "Expected an array but got " + inputNode );
}
ArrayNode array = (ArrayNode) inputNode;
for( JsonNode item : array )
{
if( !item.isObject() )
{
throw new ValueSerializationException( "Expected an object but got " + inputNode );
}
JsonNode keyNode = item.get( "key" );
JsonNode valueNode = item.get( "value" );
K key = keyDeserializer.map( keyNode );
V value = valueDeserializer.map( valueNode );
if( key != null )
{
map.put( key, value );
}
}
}
private static boolean isNullOrMissing( JsonNode inputNode )
{
return inputNode == null || inputNode.isNull() || inputNode.isMissingNode();
}
}