Initial Response output buffering support

impl-servlet/src/main/java/org/ocpsoft/rewrite/servlet/config/OutputBuffer.java

@@ -0,0 +1,20 @@
+package org.ocpsoft.rewrite.servlet.config;
+
+import java.io.InputStream;
+
+import javax.servlet.ServletResponse;
+
+/**
+ * A piece of work to be done on the fully buffered {@link ServletResponse#getOutputStream()} before flushing to the
+ * client, once the control of the application has been returned to Rewrite.
+ * 
+ * @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
+ * 
+ */
+public interface OutputBuffer
+{
+   /**
+    * Perform any manipulation of the fully buffered {@link ServletResponse#getOutputStream()} contents. 
+    */
+   InputStream execute(InputStream input);
+}

impl-servlet/src/main/java/org/ocpsoft/rewrite/servlet/config/Response.java

@@ -15,11 +15,14 @@
  */
 package org.ocpsoft.rewrite.servlet.config;
 
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServletResponse;
 
 import org.ocpsoft.rewrite.context.EvaluationContext;
 import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
+import org.ocpsoft.rewrite.servlet.impl.HttpRewriteWrappedResponse;
 
 /**
  * Responsible for adding various properties such as headers and cookies to the {@link HttpServletResponse}
@@ -28,6 +31,28 @@
  */
 public abstract class Response extends HttpOperation
 {
+   /**
+    * Add the given {@link OutputBuffer} instances to the current {@link ServletResponse}. This will activate response
+    * buffering on the current {@link ServletRequest} - meaning that generated output will not be sent to the client
+    * until the entire request has completed and all registered {@link OutputBuffer} instances have been executed.
+    * 
+    * @param bufferedResponseToLowercase2
+    * 
+    * @throws IllegalStateException When output has already been written to the client.
+    */
+   public static Response withOutputBufferedBy(final OutputBuffer... buffers) throws IllegalStateException
+   {
+      return new Response() {
+         @Override
+         public void performHttp(HttpServletRewrite event, EvaluationContext context)
+         {
+            for (OutputBuffer buffer : buffers) {
+               HttpRewriteWrappedResponse.getInstance(event.getRequest()).addBufferStage(buffer);
+            }
+         }
+      };
+   }
+
    /**
     * Create an {@link org.ocpsoft.rewrite.config.Operation} that adds a header to the {@link HttpServletResponse}
     */
@@ -71,7 +96,8 @@ public void performHttp(final HttpServletRewrite event, final EvaluationContext
    }
 
    /**
-    * Create an {@link org.ocpsoft.rewrite.config.Operation} that adds a {@link Cookie} to the {@link HttpServletResponse}
+    * Create an {@link org.ocpsoft.rewrite.config.Operation} that adds a {@link Cookie} to the
+    * {@link HttpServletResponse}
     */
    public static Response addCookie(final Cookie cookie)
    {
@@ -100,7 +126,5 @@ public String toString()
    {
       return "Response";
    }
-
-
 
 }

impl-servlet/src/main/java/org/ocpsoft/rewrite/servlet/impl/DefaultRewriteLifecycleListener.java

@@ -0,0 +1,48 @@
+package org.ocpsoft.rewrite.servlet.impl;
+
+import org.ocpsoft.rewrite.event.Rewrite;
+import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
+import org.ocpsoft.rewrite.servlet.spi.RewriteLifecycleListener;
+
+public class DefaultRewriteLifecycleListener implements RewriteLifecycleListener<HttpServletRewrite>
+{
+
+   @Override
+   public boolean handles(Rewrite payload)
+   {
+      return payload instanceof HttpServletRewrite;
+   }
+
+   @Override
+   public int priority()
+   {
+      return Integer.MAX_VALUE;
+   }
+
+   @Override
+   public void afterInboundLifecycle(HttpServletRewrite event)
+   {
+      HttpRewriteWrappedResponse.getInstance(event.getRequest()).flushBufferedStreams();
+   }
+
+   @Override
+   public void beforeInboundLifecycle(HttpServletRewrite event)
+   {}
+
+   @Override
+   public void beforeInboundRewrite(HttpServletRewrite event)
+   {}
+
+   @Override
+   public void afterInboundRewrite(HttpServletRewrite event)
+   {}
+
+   @Override
+   public void beforeOutboundRewrite(HttpServletRewrite event)
+   {}
+
+   @Override
+   public void afterOutboundRewrite(HttpServletRewrite event)
+   {}
+
+}

impl-servlet/src/main/java/org/ocpsoft/rewrite/servlet/impl/HttpRewriteWrappedResponse.java

@@ -16,9 +16,17 @@
 
 package org.ocpsoft.rewrite.servlet.impl;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
+import java.io.UnsupportedEncodingException;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 import java.util.Locale;
 
 import javax.servlet.ServletContext;
@@ -29,11 +37,16 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpServletResponseWrapper;
 
+import org.ocpsoft.common.util.Streams;
 import org.ocpsoft.rewrite.event.Rewrite;
+import org.ocpsoft.rewrite.exception.RewriteException;
 import org.ocpsoft.rewrite.servlet.RewriteLifecycleContext;
+import org.ocpsoft.rewrite.servlet.config.OutputBuffer;
 import org.ocpsoft.rewrite.servlet.event.BaseRewrite.Flow;
 import org.ocpsoft.rewrite.servlet.http.event.HttpOutboundServletRewrite;
 import org.ocpsoft.rewrite.servlet.spi.RewriteLifecycleListener;
+import org.ocpsoft.rewrite.servlet.wrapper.BufferedResponseToLowercase1;
+import org.ocpsoft.rewrite.servlet.wrapper.BufferedResponseToLowercase2;
 import org.ocpsoft.rewrite.spi.RewriteProvider;
 
 /**
@@ -42,13 +55,157 @@
 public class HttpRewriteWrappedResponse extends HttpServletResponseWrapper
 {
    private final HttpServletRequest request;
+   private final static String INSTANCE_KEY = HttpRewriteWrappedResponse.class.getName() + "_instance";
+
+   public static HttpRewriteWrappedResponse getInstance(HttpServletRequest request)
+   {
+      return (HttpRewriteWrappedResponse) request.getAttribute(INSTANCE_KEY);
+   }
 
    public HttpRewriteWrappedResponse(final HttpServletRequest request, final HttpServletResponse response)
    {
       super(response);
       this.request = request;
+
+      if (getInstance(request) == null) {
+         request.setAttribute(INSTANCE_KEY, this);
+      }
+   }
+
+   /*
+    * Buffering Facilities
+    */
+   private ByteArrayOutputStream stream = new ByteArrayOutputStream();
+   private PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(stream,
+            Charset.forName(getCharacterEncoding())), true);
+   private List<OutputBuffer> bufferedStages = new ArrayList<OutputBuffer>();
+
+   public boolean isBufferingActive()
+   {
+      return !bufferedStages.isEmpty();
+   }
+
+   public void addBufferStage(OutputBuffer stage)
+   {
+      this.bufferedStages.add(stage);
+   }
+
+   public void flushBufferedStreams()
+   {
+      if (isBufferingActive())
+      {
+         try {
+            InputStream result = new ByteArrayInputStream(stream.toByteArray());
+            for (OutputBuffer stage : bufferedStages) {
+               result = stage.execute(result);
+            }
+            Streams.copy(result, getResponse().getOutputStream());
+            if (printWriter != null) {
+               printWriter.close();
+            }
+            if (stream != null) {
+               stream.close();
+            }
+         }
+         catch (IOException e) {
+            // TODO what should we really do here?
+            e.printStackTrace();
+         }
+      }
+   }
+
+   @Override
+   public String toString()
+   {
+      if (isBufferingActive())
+      {
+         try {
+            return stream.toString(getCharacterEncoding());
+         }
+         catch (UnsupportedEncodingException e) {
+            throw new RewriteException("Response accepted invalid character encoding " + getCharacterEncoding(), e);
+         }
+      }
+      else
+         return super.toString();
    }
 
+   @Override
+   public PrintWriter getWriter()
+   {
+      if (isBufferingActive())
+         return printWriter;
+      else
+         try {
+            return super.getWriter();
+         }
+         catch (IOException e) {
+            throw new RewriteException(e);
+         }
+   }
+
+   @Override
+   public ServletOutputStream getOutputStream()
+   {
+      if (isBufferingActive())
+         return new ByteArrayServletOutputStream(stream);
+      else
+         try {
+            return super.getOutputStream();
+         }
+         catch (IOException e) {
+            throw new RewriteException(e);
+         }
+   }
+
+   @Override
+   public void setContentLength(int contentLength)
+   {
+      /*
+       * Prevent content-length being set as the page might be modified.
+       */
+      if (!isBufferingActive())
+         super.setContentLength(contentLength);
+   }
+
+   @Override
+   public void flushBuffer() throws IOException
+   {
+      if (isBufferingActive())
+         stream.flush();
+      else
+         super.flushBuffer();
+   }
+
+   private class ByteArrayServletOutputStream extends ServletOutputStream
+   {
+      private ByteArrayOutputStream outputStream;
+
+      public ByteArrayServletOutputStream(ByteArrayOutputStream outputStream)
+      {
+         this.outputStream = outputStream;
+      }
+
+      public void write(int b)
+      {
+         outputStream.write(b);
+      }
+
+      public void write(byte[] bytes) throws IOException
+      {
+         outputStream.write(bytes);
+      }
+
+      public void write(byte[] bytes, int off, int len)
+      {
+         outputStream.write(bytes, off, len);
+      }
+   }
+
+   /*
+    * End buffering facilities
+    */
+
    public HttpServletRequest getRequest()
    {
       return request;
@@ -269,41 +426,6 @@ public String getCharacterEncoding()
       return super.getCharacterEncoding();
    }
 
-   @Override
-   public ServletOutputStream getOutputStream() throws IOException
-   {
-      // TODO Auto-generated method stub
-      return super.getOutputStream();
-   }
-
-   @Override
-   public PrintWriter getWriter() throws IOException
-   {
-      // TODO Auto-generated method stub
-      return super.getWriter();
-   }
-
-   @Override
-   public void setContentLength(int len)
-   {
-      // TODO Auto-generated method stub
-      super.setContentLength(len);
-   }
-
-   @Override
-   public void setContentType(String type)
-   {
-      // TODO Auto-generated method stub
-      super.setContentType(type);
-   }
-
-   @Override
-   public String getContentType()
-   {
-      // TODO Auto-generated method stub
-      return super.getContentType();
-   }
-
    @Override
    public void setBufferSize(int size)
    {
@@ -318,13 +440,6 @@ public int getBufferSize()
       return super.getBufferSize();
    }
 
-   @Override
-   public void flushBuffer() throws IOException
-   {
-      // TODO Auto-generated method stub
-      super.flushBuffer();
-   }
-
    @Override
    public boolean isCommitted()
    {
@@ -374,5 +489,4 @@ public boolean isWrapperFor(Class wrappedType)
       return super.isWrapperFor(wrappedType);
    }
 
-
 }

impl-servlet/src/main/resources/META-INF/services/org.ocpsoft.rewrite.servlet.spi.RewriteLifecycleListener

@@ -0,0 +1 @@
+org.ocpsoft.rewrite.servlet.impl.DefaultRewriteLifecycleListener