/*

  * 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.giraph.comm;

 import org.apache.giraph.graph.BspUtils;

 import org.apache.giraph.utils.ArrayListWritable;

 import org.apache.hadoop.io.Writable;

 /**

  * Wrapper around {@link ArrayListWritable} that allows the message class to

  * be set prior to calling readFields().

  *

  * @param <M> message type

  */

 public class MsgList<M extends Writable> extends ArrayListWritable<M> {

   /** Defining a layout version for a serializable class. */

   private static final long serialVersionUID = 100L;

   /**

    * Default constructor.

    */

   public MsgList() {

     super();

   }

   /**

    * Copy constructor.

    *

    * @param msgList List of messages for writing.

    */

   public MsgList(MsgList<M> msgList) {

     super(msgList);

   }

   @SuppressWarnings("unchecked")

   @Override

   public void setClass() {

     setClass((Class<M>) BspUtils.getMessageValueClass(getConf()));

   }

 }