Author: fmeschbe
Date: Thu Dec 10 19:50:45 2009
New Revision: 889389
URL: http://svn.apache.org/viewvc?rev=889389&view=rev
Log:
SLING-1180 Add default HEAD servlet simulating HEAD by doing a GET droppping
any output
Added:
sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java
(with props)
Added:
sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java
URL:
http://svn.apache.org/viewvc/sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java?rev=889389&view=auto
==============================================================================
---
sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java
(added)
+++
sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java
Thu Dec 10 19:50:45 2009
@@ -0,0 +1,197 @@
+/*
+ * 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.apache.sling.servlets.get.impl;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.Writer;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletException;
+import javax.servlet.ServletOutputStream;
+
+import org.apache.sling.api.SlingConstants;
+import org.apache.sling.api.SlingHttpServletRequest;
+import org.apache.sling.api.SlingHttpServletResponse;
+import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
+import org.apache.sling.api.wrappers.SlingHttpServletRequestWrapper;
+import org.apache.sling.api.wrappers.SlingHttpServletResponseWrapper;
+
+/**
+ * The <code>DefaultHeadServlet</code> class implements default support for the
+ * HTTP <i>HEAD</i> request method. It basically wraps the response to provide
+ * output which does not really write to the client and the forwards to the
same
+ * requested URL (resource actually) acting as if the request was placed with a
+ * <i>GET</i> method.
+ *
+ * @scr.component immediate="true" metatype="no" policy="ignore"
+ * @scr.service interface="javax.servlet.Servlet"
+ * @scr.property name="service.description" value="Default HEAD Servlet"
+ * @scr.property name="service.vendor" value="The Apache Software Foundation"
+ * Use this as a default servlet for Sling
+ * @scr.property name="sling.servlet.resourceTypes"
+ * value="sling/servlet/default"
+ * @scr.property name="sling.servlet.prefix" value="-1" type="Integer" Generic
+ * handler for all get requests
+ * @scr.property name="sling.servlet.methods" value="HEAD"
+ */
+public class DefaultHeadServlet extends SlingSafeMethodsServlet {
+
+ private static final long serialVersionUID = 7416222678552027044L;
+
+ @Override
+ protected void doHead(SlingHttpServletRequest request,
+ SlingHttpServletResponse response) throws ServletException,
+ IOException {
+
+ // don't do nothing if the request has already been committed
+ // or this servlet is called for a servlet include
+ if (response.isCommitted()
+ || request.getAttribute(SlingConstants.ATTR_REQUEST_SERVLET) !=
null) {
+ return;
+ }
+
+ request = new HeadServletRequest(request);
+ response = new HeadServletResponse(response);
+
+ RequestDispatcher dispatcher =
request.getRequestDispatcher(request.getResource());
+ if (dispatcher != null) {
+ dispatcher.forward(request, response);
+ }
+ }
+
+ /**
+ * The <code>HeadServletRequest</code> is a Sling request wrapper which
+ * simulates a GET request to the included servlets/scripts such that the
+ * HEAD request acts as if a GET request is being processed without any
+ * response data being sent back.
+ */
+ private static class HeadServletRequest extends
+ SlingHttpServletRequestWrapper {
+
+ public HeadServletRequest(SlingHttpServletRequest wrappedRequest) {
+ super(wrappedRequest);
+ }
+
+ @Override
+ public String getMethod() {
+ return "GET";
+ }
+ }
+
+ /**
+ * The <code>HeadServletResponse</code> is a Sling response wrapper which
+ * ensures that nothing will ever be written by return null writers or
+ * output streams.
+ */
+ private static class HeadServletResponse extends
+ SlingHttpServletResponseWrapper {
+
+ private ServletOutputStream stream;
+
+ private PrintWriter writer;
+
+ public HeadServletResponse(SlingHttpServletResponse wrappedResponse) {
+ super(wrappedResponse);
+ }
+
+ @Override
+ public ServletOutputStream getOutputStream() {
+ if (writer != null) {
+ throw new IllegalStateException("Writer already obtained");
+ }
+
+ if (stream == null) {
+ stream = new NullServletOutputStream();
+ }
+
+ return stream;
+ }
+
+ @Override
+ public PrintWriter getWriter() {
+ if (stream != null) {
+ throw new IllegalStateException("OutputStream already
obtained");
+ }
+
+ if (writer == null) {
+ writer = new PrintWriter(new NullWriter());
+ }
+
+ return writer;
+ }
+ }
+
+ /**
+ * The <code>NullServletOutputStream</code> is a
+ * <code>ServletOutputStream</code> which simply does not write out
+ * anything.
+ *
+ * @see HeadServletResponse#getOutputStream()
+ */
+ private static class NullServletOutputStream extends ServletOutputStream {
+ @Override
+ public void write(int b) {
+ }
+
+ @Override
+ public void write(byte[] b) {
+ }
+
+ @Override
+ public void write(byte[] b, int off, int len) {
+ }
+ }
+
+ /**
+ * The <code>NullWriter</code> is a <code>Writer</code> which simply does
+ * not write out anything.
+ *
+ * @see HeadServletResponse#getWriter()
+ */
+ private static class NullWriter extends Writer {
+ @Override
+ public void write(char[] cbuf, int off, int len) {
+ }
+
+ @Override
+ public void write(char[] cbuf) {
+ }
+
+ @Override
+ public void write(int c) {
+ }
+
+ @Override
+ public void write(String str) {
+ }
+
+ @Override
+ public void write(String str, int off, int len) {
+ }
+
+ @Override
+ public void flush() {
+ }
+
+ @Override
+ public void close() {
+ }
+ }
+}
Propchange:
sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java
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svn:eol-style = native
Propchange:
sling/trunk/bundles/servlets/get/src/main/java/org/apache/sling/servlets/get/impl/DefaultHeadServlet.java
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svn:keywords = Author Date Id Revision Rev Url
