查看本类的 API文档回源码主页

   /*
    *  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.mina.filter.codec;
  
  import java.util.Queue;
  import java.util.concurrent.ConcurrentLinkedQueue;
  
  import org.apache.mina.core.buffer.IoBuffer;
  
  /**
   * A {@link ProtocolEncoderOutput} based on queue.
   *
   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
   */
  public abstract class AbstractProtocolEncoderOutput implements ProtocolEncoderOutput {
      private final Queue<Object> messageQueue = new ConcurrentLinkedQueue<Object>();
  
      private boolean buffersOnly = true;
  
      public AbstractProtocolEncoderOutput() {
          // Do nothing
      }
  
      public Queue<Object> getMessageQueue() {
          return messageQueue;
      }
  
      public void write(Object encodedMessage) {
          if (encodedMessage instanceof IoBuffer) {
              IoBuffer buf = (IoBuffer) encodedMessage;
              if (buf.hasRemaining()) {
                  messageQueue.offer(buf);
              } else {
                  throw new IllegalArgumentException("buf is empty. Forgot to call flip()?");
              }
          } else {
              messageQueue.offer(encodedMessage);
              buffersOnly = false;
          }
      }
  
      public void mergeAll() {
          if (!buffersOnly) {
              throw new IllegalStateException("the encoded message list contains a non-buffer.");
          }
  
          final int size = messageQueue.size();
  
          if (size < 2) {
              // no need to merge!
              return;
          }
  
          // Get the size of merged BB
          int sum = 0;
          for (Object b : messageQueue) {
              sum += ((IoBuffer) b).remaining();
          }
  
          // Allocate a new BB that will contain all fragments
          IoBuffer newBuf = IoBuffer.allocate(sum);
  
          // and merge all.
          for (;;) {
              IoBuffer buf = (IoBuffer) messageQueue.poll();
              if (buf == null) {
                  break;
              }
  
              newBuf.put(buf);
          }
  
          // Push the new buffer finally.
          newBuf.flip();
          messageQueue.add(newBuf);
      }
  }