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/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. 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. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.pdx;
/**
* The PdxSerializer interface allows domain classes to be
* serialized and deserialized as PDXs without modification
* of the domain class. It only requires that the domain class
* have a public zero-arg constructor and that it provides read and write access
* to the PDX serialized fields.
* GemFire allows a single PdxSerializer to be configured on a cache
* using {@link com.gemstone.gemfire.cache.CacheFactory#setPdxSerializer(PdxSerializer) setPdxSerializer}
* or {@link com.gemstone.gemfire.cache.client.ClientCacheFactory#setPdxSerializer(PdxSerializer) client setPdxSerializer}.
* It can also be configured in cache.xml using the pdx-serializer element.
* The same PdxSerializer should be configured on each member of a distributed
* system that can serialize or deserialize PDX data.
*
The {@link #toData toData} method is used for serialization; {@link #fromData fromData} is used for deserialization.
* The order in which fields are serialized and deserialized in these methods for the same class must match.
* For the same class toData and fromData must write the same fields each time they are called.
*
If you can modify your domain class then use {@link PdxSerializable} instead.
*
*
Simple example:
*
public class User {
final public String name;
final public int userId;
public User(String name, int userId) {
this.name = name;
this.userId = userId;
}
}
public class MyPdxSerializer implements PdxSerializer {
public boolean toData(Object o, PdxWriter out) {
if (o instanceof User) {
User u = (User)o;
out.writeString("name", u.name);
out.writeInt("userId", u.userId);
return true;
} else {
return false;
}
}
public Object fromData(Class clazz, PdxReader in) {
if (User.class.isAssignableFrom(clazz)) {
return new User(in.readString("name"), in.readInt("userId"));
} else {
return null;
}
}
}
*
*
* @author darrel
* @since 6.6
*/
public interface PdxSerializer {
/**
* This method is given an object to serialize as a PDX using the given writer.
* If it chooses to do the serialization then it must return true;
* otherwise it must return false in which case it will be serialized using
* standard serialization.
*
* @param o the object to consider serializing as a PDX
* @param out the {@link PdxWriter} to use to serialize the object
* @return true if the method serialized the object; otherwise false
*/
public boolean toData(Object o, PdxWriter out);
/**
* This method is given an class that should be
* instantiated and deserialized using the given reader.
* @param clazz the Class of the object that should be deserialized
* @param in the reader to use to obtain the field data
* @return the deserialized object. null indicates that this
* PdxSerializer does not know how to deserialize the given class.
*/
public Object fromData(Class clazz, PdxReader in);
}