geode-core/src/main/java/org/apache/geode/pdx/PdxSerializable.java

/*
 * 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.geode.pdx;

/**
 * When a domain class implements PdxSerializable it marks itself as a PDX. The implementation of
 * {@link #toData toData} provides the serialization code and {@link #fromData fromData} provides
 * the deserialization code. These methods also define each field name and field type of the PDX.
 * Domain classes should serialize and deserialize all its member fields in the same order in toData
 * and fromData method. Also fromData and toData must read and write the same fields each time they
 * are called. A domain class that implements this interface must also have a public zero-arg
 * constructor which is used during deserialization.
 *
 *
 * <p>
 * Simple example:
 *
 * <PRE>
 * public class User implements PdxSerializable {
 *   private String name;
 *   private int userId;
 *
 *   public User() {}
 *
 *   public void toData(PdxWriter out) {
 *     out.writeString("name", this.name);
 *     out.writeInt("userId", this.userId);
 *   }
 *
 *   public void fromData(PdxReader in) {
 *     this.name = in.readString("name");
 *     this.userId = in.readInt("userId");
 *   }
 * }
 * </PRE>
 *
 * @since GemFire 6.6
 */

public interface PdxSerializable {

  /**
   * Serializes the PDX fields using the given writer.
   *
   * @param writer the {@link PdxWriter} to use to write the PDX fields.
   */
  void toData(PdxWriter writer);

  /**
   * Deserializes the PDX fields using the given reader.
   *
   * @param reader the {@link PdxReader} to use to read the PDX fields.
   */
  void fromData(PdxReader reader);
}