Quadcap Embeddable Server

com/quadcap/io/TeeWriter.java

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package com.quadcap.io;

/* Copyright 2002 - 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.IOException;
import java.io.Writer;

import java.util.HashMap;
import java.util.Iterator;

/**
 *
 * @author Stan Bailes
 */
public class TeeWriter extends Writer {
    class WriterBinding {
        Writer                  w;
        boolean                 passFlush       = true;
        boolean                 passClose       = true;
        boolean                 autoFlush       = false;
        boolean                 enabled         = true;
        WriterBinding(Writer w) { this.w = w; }
    }
    
    HashMap                     writers = new HashMap();

    /**
     * Public constructor
     */
    public TeeWriter() {}

    public TeeWriter(Writer w) { addWriter("", w); }

    /**
     * Write some characters to the buffer and the downstream writer
     */
    public void write(char[] buf, int off, int len) throws IOException {
        Iterator iter = writers.values().iterator();
        while (iter.hasNext()) {
            WriterBinding wb = (WriterBinding)iter.next();
            if (wb.enabled) {
                wb.w.write(buf, off, len);
                if (wb.autoFlush) {
                    wb.w.flush();
                }
            }
        }
    }

    /**
     * Flush (the downstream writer)
     */
    public void flush() throws IOException {
        Iterator iter = writers.values().iterator();
        while (iter.hasNext()) {
            WriterBinding wb = (WriterBinding)iter.next();
            if (wb.enabled && wb.passFlush) wb.w.flush();
        }
    }

    /**
     * Close (the downstream writer)
     */
    public void close() throws IOException {
        Iterator iter = writers.values().iterator();
        while (iter.hasNext()) {
            WriterBinding wb = (WriterBinding)iter.next();
            if (wb.enabled && wb.passClose) wb.w.close();
        } 
    }

    /**
     * Add a new writer
     */
    public void addWriter(String name, Writer w) {
        WriterBinding wb = new WriterBinding(w);
        writers.put(name, wb);
    }

    /**
     * Remove a writer
     */
    public void removeWriter(String name) {
        writers.remove(name);
    }

    public void setPassClose(String w, boolean b) throws IOException {
        getBinding(w).passClose = b;
    }

    public void setPassFlush(String w, boolean b) throws IOException {
        getBinding(w).passFlush = b;
    }
        
    public void setAutoFlush(String w, boolean b) throws IOException {
        getBinding(w).autoFlush = b;
    }

    public void setEnabled(String w, boolean b) throws IOException {
        getBinding(w).enabled = b;
    }

    final private WriterBinding getBinding(String w) throws IOException {
        WriterBinding wb = (WriterBinding)writers.get(w);
        if (wb == null) {
            throw new IOException("No writer: " + w);
        }
        return wb;
    }
            
}