| /* |
| * 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; |
| |
| import java.io.DataInput; |
| import java.io.IOException; |
| |
| /** |
| * <code>CanonicalInstantiator</code> is much like its parent <code>Instantiator</code> except that |
| * instead of needing to implement <code>newInstance()</code> you now must implement |
| * <code>newInstance(DataInput)</code>. The addition of the <code>DataInput</code> parameter allows |
| * the instance creator to optionally read data from the data input stream and use it to decide the |
| * instance to create. This allows a value that represents a canonical instance to be written by a |
| * class's {@link DataSerializer#toData} and then be read by <code>newInstance(DataInput)</code> and |
| * map it back to a canonical instance. |
| * <p> |
| * Note that {@link DataSerializer#fromData} is always called on the instance returned from |
| * <code>newInstance(DataInput)</code>. |
| * |
| * @since GemFire 5.1 |
| */ |
| public abstract class CanonicalInstantiator extends Instantiator { |
| |
| /** |
| * Creates a new <code>CanonicalInstantiator</code> that instantiates a given class. |
| * |
| * @param c The <code>DataSerializable</code> class to register. This class must have a static |
| * initializer that registers this <code>Instantiator</code>. |
| * @param classId A unique id for class <code>c</code>. The <code>classId</code> must not be zero. |
| * This has been an <code>int</code> since dsPhase1. |
| * |
| * @throws IllegalArgumentException If <code>c</code> does not implement |
| * <code>DataSerializable</code>, <code>classId</code> is less than or equal to zero. |
| * @throws NullPointerException If <code>c</code> is <code>null</code> |
| */ |
| public CanonicalInstantiator(Class<? extends DataSerializable> c, int classId) { |
| super(c, classId); |
| } |
| |
| /** |
| * This method is not supported and if called will throw UnsupportedOperationException. Use |
| * {@link #newInstance(DataInput)} instead. |
| * |
| * @throws UnsupportedOperationException in all cases |
| */ |
| @Override |
| public DataSerializable newInstance() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Creates a new "empty" instance of a <Code>DataSerializable</code> class whose state will be |
| * filled in by invoking its {@link DataSerializable#fromData fromData} method. |
| * |
| * @param in the data input that can be read to decide what instance to create. |
| * @return the new "empty" instance. |
| * @throws IOException if a read from <code>in</code> fails. |
| * @since GemFire 5.1 |
| */ |
| public abstract DataSerializable newInstance(DataInput in) throws IOException; |
| } |