org.tinygroup.jspengine.runtime.ServletResponseWrapperInclude Maven / Gradle / Ivy

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/**
 *  Copyright (c) 1997-2013, www.tinygroup.org ([email protected]).
 *
 *  Licensed under the GPL, Version 3.0 (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.gnu.org/licenses/gpl.html
 *
 *  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.tinygroup.jspengine.runtime;

import org.tinygroup.jspengine.enterprise.web.io.ByteWriter;

import javax.servlet.ServletOutputStream;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.jsp.JspWriter;
import java.io.IOException;
import java.io.PrintWriter;


/**
 * ServletResponseWrapper used by the JSP 'include' action.
 *
 * This wrapper response object is passed to RequestDispatcher.include(), so
 * that the output of the included resource is appended to that of the
 * including page.
 *
 * @author Pierre Delisle
 */

public class ServletResponseWrapperInclude extends HttpServletResponseWrapper {

    /**
     * PrintWriter which appends to the JspWriter of the including page.
     */
    private PrintWriter printWriter;

    private JspWriter jspWriter;

    // START CR 6466049
    /**
     * Indicates whether or not the wrapped JspWriter can be flushed.
     */
    private boolean canFlushWriter;
    // END CR 6466049


    public ServletResponseWrapperInclude(ServletResponse response, 
					 JspWriter jspWriter) {
	super((HttpServletResponse)response);

        this.jspWriter = jspWriter;
        if (jspWriter instanceof JspWriterImpl &&
                ((JspWriterImpl)jspWriter).shouldOutputBytes()) {
            this.printWriter = new PrintWriterWrapper((JspWriterImpl)jspWriter);
        } else {
            this.printWriter = new PrintWriter(jspWriter);
        }
            
        // START CR 6466049
        this.canFlushWriter = (jspWriter instanceof JspWriterImpl);
        // END CR 6466049
    }

    /**
     * Returns a wrapper around the JspWriter of the including page.
     */
    public PrintWriter getWriter() throws IOException {
	return printWriter;
    }

    public ServletOutputStream getOutputStream() throws IOException {
	throw new IllegalStateException();
    }

    /**
     * Clears the output buffer of the JspWriter associated with the including
     * page.
     */
    public void resetBuffer() {
	try {
	    jspWriter.clearBuffer();
	} catch (IOException ioe) {
	}
    }

    // START CR 6421712
    /**
     * Flush the wrapper around the JspWriter of the including page.
     */
    public void flushBuffer() throws IOException {
        printWriter.flush();
    }
    // END CR 6421712


    // START CR 6466049
    /**
     * Indicates whether or not the wrapped JspWriter can be flushed.
     * (BodyContent objects cannot be flushed)
     */
    public boolean canFlush() {
        return canFlushWriter;
    }
    // END CR 6466049


    // START PWC 6512276
    /** 
     * Are there any data to be flushed ?
     */
    public boolean hasData() {
        return !canFlushWriter || ((JspWriterImpl) jspWriter).hasData();

    }
    // END PWC 6512276

    static private class PrintWriterWrapper
            extends PrintWriter implements ByteWriter {

        private JspWriterImpl jspWriter;

        PrintWriterWrapper(JspWriterImpl jspWriter) {
            super(jspWriter);
            this.jspWriter = jspWriter;
        }

        public void write(byte[] buff, int off, int len, int strlen)
                throws IOException {
            jspWriter.write(buff, off, len, strlen);
        }
    }
}