ActiveMQ example source code file (TcpBufferedInputStream.java)

This example ActiveMQ source code file (TcpBufferedInputStream.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

buffer, default_buffer_size, default_buffer_size, filterinputstream, illegalargumentexception, indexoutofboundsexception, inputstream, inputstream, io, ioexception, ioexception, tcpbufferedinputstream, tcpbufferedinputstream

The ActiveMQ TcpBufferedInputStream.java source code

/**
 * 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.tcp;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * An optimized buffered input stream for Tcp
 * 
 * 
 */
public class TcpBufferedInputStream extends FilterInputStream {
    private static final int DEFAULT_BUFFER_SIZE = 8192;
    protected byte internalBuffer[];
    protected int count;
    protected int position;

    public TcpBufferedInputStream(InputStream in) {
        this(in, DEFAULT_BUFFER_SIZE);
    }

    public TcpBufferedInputStream(InputStream in, int size) {
        super(in);
        if (size <= 0) {
            throw new IllegalArgumentException("Buffer size <= 0");
        }
        internalBuffer = new byte[size];
    }

    protected void fill() throws IOException {
        byte[] buffer = internalBuffer;
        count = 0;
        position = 0;
        int n = in.read(buffer, position, buffer.length - position);
        if (n > 0) {
            count = n + position;
        }
    }

    public int read() throws IOException {
        if (position >= count) {
            fill();
            if (position >= count) {
                return -1;
            }
        }
        return internalBuffer[position++] & 0xff;
    }

    private int readStream(byte[] b, int off, int len) throws IOException {
        int avail = count - position;
        if (avail <= 0) {
            if (len >= internalBuffer.length) {
                return in.read(b, off, len);
            }
            fill();
            avail = count - position;
            if (avail <= 0) {
                return -1;
            }
        }
        int cnt = (avail < len) ? avail : len;
        System.arraycopy(internalBuffer, position, b, off, cnt);
        position += cnt;
        return cnt;
    }

    public int read(byte b[], int off, int len) throws IOException {
        if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
            throw new IndexOutOfBoundsException();
        } else if (len == 0) {
            return 0;
        }
        int n = 0;
        for (;;) {
            int nread = readStream(b, off + n, len - n);
            if (nread <= 0) {
                return (n == 0) ? nread : n;
            }
            n += nread;
            if (n >= len) {
                return n;
            }
            // if not closed but no bytes available, return
            InputStream input = in;
            if (input != null && input.available() <= 0) {
                return n;
            }
        }
    }

    public long skip(long n) throws IOException {
        if (n <= 0) {
            return 0;
        }
        long avail = count - position;
        if (avail <= 0) {
            return in.skip(n);
        }
        long skipped = (avail < n) ? avail : n;
        position += skipped;
        return skipped;
    }

    public int available() throws IOException {
        return in.available() + (count - position);
    }

    public boolean markSupported() {
        return false;
    }

    public void close() throws IOException {
        if (in != null) {
            in.close();
        }
    }
}