/*
* 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 compressionFilters;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
/**
* Implementation of <b>HttpServletResponseWrapper</b> that works with
* the CompressionServletResponseStream implementation..
*
* @author Amy Roh
* @author Dmitri Valdin
*/
public class CompressionServletResponseWrapper
extends HttpServletResponseWrapper {
// ----------------------------------------------------- Constructor
/**
* Calls the parent constructor which creates a ServletResponse adaptor
* wrapping the given response object.
*/
public CompressionServletResponseWrapper(HttpServletResponse response) {
super(response);
origResponse = response;
if (debug > 1) {
System.out.println("CompressionServletResponseWrapper constructor gets called");
}
}
// ----------------------------------------------------- Instance Variables
/**
* Original response
*/
protected HttpServletResponse origResponse = null;
/**
* Descriptive information about this Response implementation.
*/
protected static final String info = "CompressionServletResponseWrapper";
/**
* The ServletOutputStream that has been returned by
* <code>getOutputStream()</code>, if any.
*/
protected ServletOutputStream stream = null;
/**
* The PrintWriter that has been returned by
* <code>getWriter()</code>, if any.
*/
protected PrintWriter writer = null;
/**
* The threshold number to compress
*/
protected int compressionThreshold = 0;
/**
* The compression buffer size
*/
protected int compressionBuffer = 8192; // 8KB default
/**
* The mime types to compress
*/
protected String[] compressionMimeTypes = {"text/html", "text/xml", "text/plain"};
/**
* Debug level
*/
protected int debug = 0;
/**
* keeps a copy of all headers set
*/
private Map<String,String> headerCopies = new HashMap<String,String>();
// --------------------------------------------------------- Public Methods
/**
* Set threshold number
*/
public void setCompressionThreshold(int threshold) {
if (debug > 1) {
System.out.println("setCompressionThreshold to " + threshold);
}
this.compressionThreshold = threshold;
}
/**
* Set compression buffer
*/
public void setCompressionBuffer(int buffer) {
if (debug > 1) {
System.out.println("setCompressionBuffer to " + buffer);
}
this.compressionBuffer = buffer;
}
/**
* Set compressible mime types
*/
public void setCompressionMimeTypes(String[] mimeTypes) {
if (debug > 1) {
System.out.println("setCompressionMimeTypes to " + mimeTypes);
}
this.compressionMimeTypes = mimeTypes;
}
/**
* Set debug level
*/
public void setDebugLevel(int debug) {
this.debug = debug;
}
/**
* Create and return a ServletOutputStream to write the content
* associated with this Response.
*
* @exception IOException if an input/output error occurs
*/
public ServletOutputStream createOutputStream() throws IOException {
if (debug > 1) {
System.out.println("createOutputStream gets called");
}
CompressionResponseStream stream = new CompressionResponseStream(
this, origResponse.getOutputStream());
stream.setDebugLevel(debug);
stream.setCompressionThreshold(compressionThreshold);
stream.setCompressionBuffer(compressionBuffer);
stream.setCompressionMimeTypes(compressionMimeTypes);
return stream;
}
/**
* Finish a response.
*/
public void finishResponse() {
try {
if (writer != null) {
writer.close();
} else {
if (stream != null)
stream.close();
}
} catch (IOException e) {
// Ignore
}
}
// ------------------------------------------------ ServletResponse Methods
/**
* Flush the buffer and commit this response.
*
* @exception IOException if an input/output error occurs
*/
@Override
public void flushBuffer() throws IOException {
if (debug > 1) {
System.out.println("flush buffer @ GZipServletResponseWrapper");
}
((CompressionResponseStream)stream).flush();
}
/**
* Return the servlet output stream associated with this Response.
*
* @exception IllegalStateException if <code>getWriter</code> has
* already been called for this response
* @exception IOException if an input/output error occurs
*/
@Override
public ServletOutputStream getOutputStream() throws IOException {
if (writer != null)
throw new IllegalStateException("getWriter() has already been called for this response");
if (stream == null)
stream = createOutputStream();
if (debug > 1) {
System.out.println("stream is set to "+stream+" in getOutputStream");
}
return (stream);
}
/**
* Return the writer associated with this Response.
*
* @exception IllegalStateException if <code>getOutputStream</code> has
* already been called for this response
* @exception IOException if an input/output error occurs
*/
@Override
public PrintWriter getWriter() throws IOException {
if (writer != null)
return (writer);
if (stream != null)
throw new IllegalStateException("getOutputStream() has already been called for this response");
stream = createOutputStream();
if (debug > 1) {
System.out.println("stream is set to "+stream+" in getWriter");
}
String charEnc = origResponse.getCharacterEncoding();
if (debug > 1) {
System.out.println("character encoding is " + charEnc);
}
// HttpServletResponse.getCharacterEncoding() shouldn't return null
// according the spec, so feel free to remove that "if"
if (charEnc != null) {
writer = new PrintWriter(new OutputStreamWriter(stream, charEnc));
} else {
writer = new PrintWriter(stream);
}
return (writer);
}
@Override
public String getHeader(String name) {
return headerCopies.get(name);
}
@Override
public void addHeader(String name, String value) {
if (headerCopies.containsKey(name)) {
String existingValue = headerCopies.get(name);
if ((existingValue != null) && (existingValue.length() > 0)) headerCopies.put(name, existingValue + "," + value);
else headerCopies.put(name, value);
} else headerCopies.put(name, value);
super.addHeader(name, value);
}
@Override
public void setHeader(String name, String value) {
headerCopies.put(name, value);
super.setHeader(name, value);
}
}