org.apache.kafka.common.serialization.ExtendedDeserializer Maven / Gradle / Ivy

/*
 * 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.kafka.common.serialization;

import java.util.Map;

import org.apache.kafka.common.header.Headers;

/**
 * A Deserializer that has access to the headers associated with the record.
 *
 * Prefer {@link Deserializer} if access to the headers is not required. Once Kafka drops support for Java 7, the
 * {@code deserialize()} method introduced by this interface will be added to Deserializer with a default implementation
 * so that backwards compatibility is maintained. This interface may be deprecated once that happens.
 *
 * A class that implements this interface is expected to have a constructor with no parameters.
 * @param 
 * @deprecated This class has been deprecated and will be removed in a future release. Please use {@link Deserializer} instead.
 */
@Deprecated
public interface ExtendedDeserializer extends Deserializer {

    /**
     * Deserialize a record value from a byte array into a value or object.
     * @param topic topic associated with the data
     * @param headers headers associated with the record; may be empty.
     * @param data serialized bytes; may be null; implementations are recommended to handle null by returning a value or null rather than throwing an exception.
     * @return deserialized typed data; may be null
     */
    T deserialize(String topic, Headers headers, byte[] data);

    class Wrapper implements ExtendedDeserializer {

        private final Deserializer deserializer;

        public Wrapper(Deserializer deserializer) {
            this.deserializer = deserializer;
        }


        @Override
        public T deserialize(String topic, Headers headers, byte[] data) {
            return deserialize(topic, data);
        }

        @Override
        public void configure(Map configs, boolean isKey) {
            deserializer.configure(configs, isKey);
        }

        @Override
        public T deserialize(String topic, byte[] data) {
            return deserializer.deserialize(topic, data);
        }

        @Override
        public void close() {
            deserializer.close();
        }

        public static  ExtendedDeserializer ensureExtended(Deserializer deserializer) {
            return deserializer == null ?  null : deserializer instanceof ExtendedDeserializer ? (ExtendedDeserializer) deserializer : new ExtendedDeserializer.Wrapper<>(deserializer);
        }
    }
}