1   /**
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
   10    *
   11    * Unless required by applicable law or agreed to in writing, software
   12    * distributed under the License is distributed on an "AS IS" BASIS,
   13    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   14    * See the License for the specific language governing permissions and
   15    * limitations under the License.
   16    */
   17   package org.apache.activemq.transport.nio;
   18   
   19   import java.io.IOException;
   20   import java.io.InputStream;
   21   import java.nio.BufferUnderflowException;
   22   import java.nio.ByteBuffer;
   23   
   24   /**
   25    * An optimized buffered input stream for Tcp
   26    * 
   27    * @version $Revision: 1.1.1.1 $
   28    */
   29   public class NIOInputStream extends InputStream {
   30   
   31       protected int count;
   32       protected int position;
   33       private final ByteBuffer in;
   34   
   35       public NIOInputStream(ByteBuffer in) {
   36           this.in = in;
   37       }
   38   
   39       public int read() throws IOException {
   40           try {
   41               int rc = in.get() & 0xff;
   42               return rc;
   43           } catch (BufferUnderflowException e) {
   44               return -1;
   45           }
   46       }
   47   
   48       public int read(byte b[], int off, int len) throws IOException {
   49           if (in.hasRemaining()) {
   50               int rc = Math.min(len, in.remaining());
   51               in.get(b, off, rc);
   52               return rc;
   53           } else {
   54               return len == 0 ? 0 : -1;
   55           }
   56       }
   57   
   58       public long skip(long n) throws IOException {
   59           int rc = Math.min((int)n, in.remaining());
   60           in.position(in.position() + rc);
   61           return rc;
   62       }
   63   
   64       public int available() throws IOException {
   65           return in.remaining();
   66       }
   67   
   68       public boolean markSupported() {
   69           return false;
   70       }
   71   
   72       public void close() throws IOException {
   73       }
   74   }