com.mongodb.DBRefCodec Maven / Gradle / Ivy
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/*
* Copyright 2008-present MongoDB, Inc.
*
* 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 com.mongodb;
import org.bson.BsonReader;
import org.bson.BsonWriter;
import org.bson.codecs.Codec;
import org.bson.codecs.DecoderContext;
import org.bson.codecs.EncoderContext;
import org.bson.codecs.configuration.CodecRegistry;
import static com.mongodb.assertions.Assertions.notNull;
/**
* A Codec for DBRef instances.
*
* @since 3.0
*/
public class DBRefCodec implements Codec {
private final CodecRegistry registry;
/**
* Construct an instance with the given registry, which is used to encode the id of the referenced document.
*
* @param registry the non-null codec registry
*/
public DBRefCodec(final CodecRegistry registry) {
this.registry = notNull("registry", registry);
}
@Override
@SuppressWarnings({"unchecked", "rawtypes"})
public void encode(final BsonWriter writer, final DBRef value, final EncoderContext encoderContext) {
writer.writeStartDocument();
writer.writeString("$ref", value.getCollectionName());
writer.writeName("$id");
Codec codec = registry.get(value.getId().getClass());
codec.encode(writer, value.getId(), encoderContext);
if (value.getDatabaseName() != null) {
writer.writeString("$db", value.getDatabaseName());
}
writer.writeEndDocument();
}
@Override
public Class getEncoderClass() {
return DBRef.class;
}
@Override
public DBRef decode(final BsonReader reader, final DecoderContext decoderContext) {
throw new UnsupportedOperationException("DBRefCodec does not support decoding");
}
}