1929395 - replace the java webparts compression filter with an embedd…

…ed version based off of a tomcat example filter.

symmetric/src/main/java/org/jumpmind/symmetric/web/compression/CompressionServletResponseWrapper.java

@@ -0,0 +1,227 @@
+/*
+* 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 org.jumpmind.symmetric.web.compression;
+
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import javax.servlet.ServletOutputStream;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpServletResponseWrapper;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Implementation of <b>HttpServletResponseWrapper</b> that works with
+ * the CompressionServletResponseStream implementation..
+ *
+ * This package is derived from the Jakarta
+ * <a href="http://jakarta.apache.org/tomcat">Tomcat</a>
+ * examples compression filter and is distributed in SymmetricDS for convenience.
+ * 
+ * @author Amy Roh
+ * @author Dmitri Valdin
+ * @version $Revision: 496190 $, $Date: 2007-01-14 16:21:45 -0700 (Sun, 14 Jan 2007) $
+ */
+
+public class CompressionServletResponseWrapper extends HttpServletResponseWrapper {
+
+    static final Log logger = LogFactory.getLog(CompressionServletResponseWrapper.class);
+
+    /**
+     * Calls the parent constructor which creates a ServletResponse adaptor
+     * wrapping the given response object.
+     */
+
+    public CompressionServletResponseWrapper(HttpServletResponse response) {
+        super(response);
+        origResponse = response;
+        if (logger.isDebugEnabled()) {
+            logger.debug("CompressionServletResponseWrapper constructor gets called");
+        }
+    }
+
+    /**
+     * 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 threshold = 0;
+
+    /**
+     * Content type
+     */
+    protected String contentType = null;
+
+    // --------------------------------------------------------- Public Methods
+
+    /**
+     * Set content type
+     */
+    public void setContentType(String contentType) {
+        if (logger.isDebugEnabled()) {
+            logger.debug("setContentType to " + contentType);
+        }
+        this.contentType = contentType;
+        origResponse.setContentType(contentType);
+    }
+
+    /**
+     * Set threshold number
+     */
+    public void setCompressionThreshold(int threshold) {
+        if (logger.isDebugEnabled()) {
+            logger.debug("setCompressionThreshold to " + threshold);
+        }
+        this.threshold = threshold;
+    }
+
+    /**
+    * 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 (logger.isDebugEnabled()) {
+            logger.debug("createOutputStream gets called");
+        }
+
+        CompressionResponseStream stream = new CompressionResponseStream(origResponse);
+        stream.setBuffer(threshold);
+
+        return stream;
+
+    }
+
+    /**
+     * Finish a response.
+     */
+    public void finishResponse() {
+        try {
+            if (writer != null) {
+                writer.close();
+            } else {
+                if (stream != null)
+                    stream.close();
+            }
+        } catch (IOException e) {
+        }
+    }
+
+    // ------------------------------------------------ ServletResponse Methods
+
+    /**
+     * Flush the buffer and commit this response.
+     *
+     * @exception IOException if an input/output error occurs
+     */
+    public void flushBuffer() throws IOException {
+        if (logger.isDebugEnabled()) {
+            logger.debug("flush buffer @ CompressionServletResponseWrapper");
+        }
+        ((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
+     */
+    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 (logger.isDebugEnabled()) {
+            logger.debug("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
+     */
+    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 (logger.isDebugEnabled()) {
+            logger.debug("stream is set to " + stream + " in getWriter");
+        }
+        //String charset = getCharsetFromContentType(contentType);
+        String charEnc = origResponse.getCharacterEncoding();
+        if (logger.isDebugEnabled()) {
+            logger.debug("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);
+
+    }
+
+    public void setContentLength(int length) {
+    }
+
+}