/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
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 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
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 */

package com.sun.appserv.web.cache.filter;

import java.io.IOException;
import java.io.ByteArrayOutputStream;

import javax.servlet.ServletOutputStream;

/**
 * an output stream wrapper to cache response bytes
 */
public class CachingOutputStreamWrapper extends ServletOutputStream {

    ByteArrayOutputStream baos;

    public CachingOutputStreamWrapper() {
        this.baos = new ByteArrayOutputStream(4096);
    }

    /**
     * Write the specified byte to our output stream.
     *
     * @param b The byte to be written
     *
     * @exception IOException if an input/output error occurs
     */
    public void write(int b) throws IOException {
        baos.write(b);
    }

    /**
     * Write <code>b.length</code> bytes from the specified byte array
     * to our output stream.
     *
     * @param b The byte array to be written
     *
     * @exception IOException if an input/output error occurs
     */
    public void write(byte b[]) throws IOException {
        baos.write(b, 0, b.length);
    }

    /**
     * Write <code>len</code> bytes from the specified byte array, starting
     * at the specified offset, to our output stream.
     *
     * @param b The byte array containing the bytes to be written
     * @param off Zero-relative starting offset of the bytes to be written
     * @param len The number of bytes to be written
     *
     * @exception IOException if an input/output error occurs
     */
    public void write(byte b[], int off, int len) throws IOException {
        baos.write(b, off, len);
    }

    /**
     * Flush any buffered data for this output stream, which also causes the
     * response to be committed.
     */
    public void flush() throws IOException {
        // nothing to do with cached bytes
    }

    /**
     * Close this output stream, causing any buffered data to be flushed and
     * any further output data to throw an IOException.
     */
    public void close() throws IOException {
        // nothing to do with cached bytes
    }

    /**
     * return the cached bytes
     */
    public byte[] getBytes() {
        return baos.toByteArray();
    }
}