Java tutorial
/* * Copyright 2011 VZ Netzwerke Ltd * Copyright 2014 devbliss GmbH * * 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.mongojack.internal; import java.io.IOException; import org.bson.types.ObjectId; import org.mongojack.DBRef; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.JsonSerializer; import com.fasterxml.jackson.databind.SerializerProvider; /** * Serializer for object ids, serialises strings or byte arrays to an ObjectId * class * * @author James Roper * @since 1.0 */ public class ObjectIdSerializer extends JsonSerializer { @Override public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException { if (value instanceof Iterable) { jgen.writeStartArray(); for (Object item : (Iterable) value) { jgen.writeObject(serialiseObject(item)); } jgen.writeEndArray(); } else { jgen.writeObject(serialiseObject(value)); } } private Object serialiseObject(Object value) throws JsonMappingException { if (value == null) { return null; } else if (value instanceof String) { return new ObjectId((String) value); } else if (value instanceof byte[]) { return new ObjectId((byte[]) value); } else if (value instanceof DBRef) { DBRef dbRef = (DBRef) value; Object id = serialiseObject(dbRef.getId()); if (id == null) { return null; } return new com.mongodb.DBRef(null, dbRef.getCollectionName(), id); } else if (value instanceof ObjectId) { return value; } else { throw new JsonMappingException( "Cannot deserialise object of type " + value.getClass() + " to ObjectId"); } } }