Quadcap Embeddable Server

com/quadcap/io/LogInputStream.java

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package com.quadcap.io;

/* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.*;

import com.quadcap.util.Debug;
import com.quadcap.util.Util;

/**
 * A filter input stream that tees off input into a log file, with an
 * optional prefix for each line (delimited by newline), which can be
 * used to identify the stream.
 *
 * @author Stan Bailes
 */

public class LogInputStream extends InputStream {
    InputStream         in;
    OutputStream        log;
    byte[]              prefix;
    boolean             bol = true;
    
    /**
     * Construct a new log input stream
     *
     * @param is the underlying input stream
     * @param log the log stream
     * @param prefix a string identifying this log stream to be prefixed
     *          to every line output by this filter.
     */
    public LogInputStream(InputStream is, OutputStream log, String prefix) {
        this.in = is;
        this.log = log;
        this.prefix = prefix.getBytes();
    }

    /**
     * Read (and log) a byte
     *
     * @exception IOException may be thrown
     */
    synchronized public int read() throws IOException {
        int b = in.read();
        if (bol) log.write(prefix);
        log.write(b);
        bol = (b == '\n');
        return b;
    }

    /**
     * Close the underlying stream and the log output stream
     *
     * @exception IOException may be thrown
     */
    public void close() throws IOException {
        in.close();
        log.close();
    }
}