| /** |
| * |
| * 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.activemq.transport.nio; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.Channel; |
| import java.nio.channels.ClosedChannelException; |
| import java.nio.channels.ReadableByteChannel; |
| import java.nio.channels.SelectionKey; |
| import java.nio.channels.Selector; |
| import java.nio.channels.SocketChannel; |
| |
| /** |
| * Implementation of InputStream using Java NIO channel,direct buffer and |
| * Selector |
| */ |
| public class NIOBufferedInputStream extends InputStream { |
| |
| private final static int BUFFER_SIZE = 8192; |
| |
| private SocketChannel sc = null; |
| |
| private ByteBuffer bb = null; |
| |
| private Selector rs = null; |
| |
| public NIOBufferedInputStream(ReadableByteChannel channel, int size) |
| throws ClosedChannelException, IOException { |
| |
| if (size <= 0) { |
| throw new IllegalArgumentException("Buffer size <= 0"); |
| } |
| |
| this.bb = ByteBuffer.allocateDirect(size); |
| this.sc = (SocketChannel) channel; |
| |
| this.sc.configureBlocking(false); |
| |
| this.rs = Selector.open(); |
| |
| sc.register(rs, SelectionKey.OP_READ); |
| |
| bb.position(0); |
| bb.limit(0); |
| } |
| |
| public NIOBufferedInputStream(ReadableByteChannel channel) |
| throws ClosedChannelException, IOException { |
| this(channel, BUFFER_SIZE); |
| } |
| |
| public int available() throws IOException { |
| if (!rs.isOpen()) |
| throw new IOException("Input Stream Closed"); |
| |
| return bb.remaining(); |
| } |
| |
| public void close() throws IOException { |
| if (rs.isOpen()) { |
| rs.close(); |
| |
| if (sc.isOpen()) { |
| sc.socket().shutdownInput(); |
| sc.socket().close(); |
| } |
| |
| bb = null; |
| sc = null; |
| } |
| } |
| |
| public int read() throws IOException { |
| if (!rs.isOpen()) |
| throw new IOException("Input Stream Closed"); |
| |
| if (!bb.hasRemaining()) { |
| try { |
| fill(1); |
| } catch (ClosedChannelException e) { |
| close(); |
| return -1; |
| } |
| } |
| |
| return (bb.get() & 0xFF); |
| } |
| |
| public int read(byte[] b, int off, int len) throws IOException { |
| int bytesCopied = -1; |
| |
| if (!rs.isOpen()) |
| throw new IOException("Input Stream Closed"); |
| |
| while (bytesCopied == -1) { |
| if (bb.hasRemaining()) { |
| bytesCopied = (len < bb.remaining() ? len : bb.remaining()); |
| bb.get(b, off, bytesCopied); |
| } else { |
| try { |
| fill(1); |
| } catch (ClosedChannelException e) { |
| close(); |
| return -1; |
| } |
| } |
| } |
| |
| return bytesCopied; |
| } |
| |
| public long skip(long n) throws IOException { |
| long skiped = 0; |
| |
| if (!rs.isOpen()) |
| throw new IOException("Input Stream Closed"); |
| |
| while (n > 0) { |
| if (n <= bb.remaining()) { |
| skiped += n; |
| bb.position(bb.position() + (int) n); |
| n = 0; |
| } else { |
| skiped += bb.remaining(); |
| n -= bb.remaining(); |
| |
| bb.position(bb.limit()); |
| |
| try { |
| fill((int) n); |
| } catch (ClosedChannelException e) { |
| close(); |
| return skiped; |
| } |
| } |
| } |
| |
| return skiped; |
| } |
| |
| private void fill(int n) throws IOException, ClosedChannelException { |
| int bytesRead = -1; |
| |
| if ((n <= 0) || (n <= bb.remaining())) |
| return; |
| |
| bb.compact(); |
| |
| n = (bb.remaining() < n ? bb.remaining() : n); |
| |
| for (;;) { |
| bytesRead = sc.read(bb); |
| |
| if (bytesRead == -1) |
| throw new ClosedChannelException(); |
| |
| n -= bytesRead; |
| |
| if (n <= 0) |
| break; |
| |
| rs.select(0); |
| rs.selectedKeys().clear(); |
| } |
| |
| bb.flip(); |
| } |
| } |