First cut at a new filter strategy

WW-2193 git-svn-id: https://svn.apache.org/repos/asf/struts/struts2/trunk@670209 13f79535-47bb-0310-9956-ffa450edef68
2026-08-11 01:27:14 +00:00 · 2008-06-21 15:13:59 +00:00
parent 37371b3684
commit 8f5e79d987
8 changed files with 687 additions and 0 deletions
@@ -0,0 +1,69 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import org.apache.struts2.dispatcher.Dispatcher;
+import org.apache.struts2.StrutsException;
+import com.opensymphony.xwork2.ActionContext;
+
+/**
+ * Contains cleanup operations in all stages for filters
+ */
+public class CleanupOperations {
+
+    private Dispatcher dispatcher;
+
+    public CleanupOperations(Dispatcher dispatcher) {
+        this.dispatcher = dispatcher;
+    }
+
+    /**
+     * Cleans up the dispatcher instance
+     */
+    public void cleanupDispatcher() {
+        if (dispatcher == null) {
+            throw new StrutsException("something is seriously wrong, Dispatcher is not initialized (null) ");
+        } else {
+            try {
+                dispatcher.cleanup();
+            } finally {
+                ActionContext.setContext(null);
+            }
+        }
+    }
+
+    /**
+     * Cleans up a request of thread locals
+     */
+    public void cleanupRequest() {
+        // always dontClean up the thread request, even if an action hasn't been executed
+        ActionContext.setContext(null);
+        Dispatcher.setInstance(null);
+    }
+
+    /**
+     * Cleans up after the initialization process
+     */
+    public void cleanupInit() {
+        ActionContext.setContext(null);
+    }
+
+}
@@ -0,0 +1,79 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import org.apache.struts2.dispatcher.Dispatcher;
+import org.apache.struts2.dispatcher.StaticContentLoader;
+import org.apache.struts2.dispatcher.mapper.ActionMapping;
+import org.apache.struts2.RequestUtils;
+
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Contains execution operations for filters
+ */
+public class ExecuteOperations {
+    private ServletContext servletContext;
+    private Dispatcher dispatcher;
+
+    public ExecuteOperations(ServletContext servletContext, Dispatcher dispatcher) {
+        this.dispatcher = dispatcher;
+        this.servletContext = servletContext;
+    }
+
+    /**
+     * Tries to execute a request for a static resource
+     * @return True if it was handled, false if the filter should fall through
+     * @throws IOException
+     * @throws ServletException
+     */
+    public boolean executeStaticResourceRequest(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
+        // there is no action in this request, should we look for a static resource?
+        String resourcePath = RequestUtils.getServletPath(request);
+
+        if ("".equals(resourcePath) && null != request.getPathInfo()) {
+            resourcePath = request.getPathInfo();
+        }
+
+        StaticContentLoader staticResourceLoader = dispatcher.getContainer().getInstance(StaticContentLoader.class);
+        if (staticResourceLoader.canHandle(resourcePath)) {
+            staticResourceLoader.findStaticResource(resourcePath, request, response);
+            // The framework did its job here
+            return true;
+
+        } else {
+            // this is a normal request, let it pass through
+            return false;
+        }
+    }
+
+    /**
+     * Executes an action
+     * @throws ServletException
+     */
+    public void executeAction(HttpServletRequest request, HttpServletResponse response, ActionMapping mapping) throws ServletException {
+        dispatcher.serviceAction(request, response, servletContext, mapping);
+    }
+}
@@ -0,0 +1,106 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import com.opensymphony.xwork2.util.logging.LoggerFactory;
+import org.apache.struts2.dispatcher.Dispatcher;
+import org.apache.struts2.dispatcher.StaticContentLoader;
+import org.apache.struts2.util.ClassLoaderUtils;
+
+import javax.servlet.FilterConfig;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Contains initialization operations
+ */
+public class InitOperations {
+
+    public InitOperations() {
+    }
+
+    /**
+     * Initializes the internal Struts logging
+     */
+    public void initLogging(FilterConfig filterConfig) {
+        String factoryName = filterConfig.getInitParameter("loggerFactory");
+        if (factoryName != null) {
+            try {
+                Class cls = ClassLoaderUtils.loadClass(factoryName, this.getClass());
+                LoggerFactory fac = (LoggerFactory) cls.newInstance();
+                LoggerFactory.setLoggerFactory(fac);
+            } catch (InstantiationException e) {
+                System.err.println("Unable to instantiate logger factory: " + factoryName + ", using default");
+                e.printStackTrace();
+            } catch (IllegalAccessException e) {
+                System.err.println("Unable to access logger factory: " + factoryName + ", using default");
+                e.printStackTrace();
+            } catch (ClassNotFoundException e) {
+                System.err.println("Unable to locate logger factory class: " + factoryName + ", using default");
+                e.printStackTrace();
+            }
+        }
+    }
+
+    /**
+     * Creates and initializes the dispatcher
+     */
+    public Dispatcher initDispatcher(FilterConfig filterConfig) {
+        Dispatcher dispatcher = createDispatcher(filterConfig);
+        dispatcher.init();
+        return dispatcher;
+    }
+
+    /**
+     * Initializes the static content loader with the filter configuration
+     */
+    public StaticContentLoader initStaticContentLoader(FilterConfig filterConfig, Dispatcher dispatcher) {
+        StaticContentLoader loader = dispatcher.getContainer().getInstance(StaticContentLoader.class);
+        loader.setFilterConfig(filterConfig);
+        return loader;
+    }
+
+    /**
+     * @return The dispatcher on the thread.
+     * @throws IllegalStateException If there is no dispatcher available
+     */
+    public Dispatcher findDispatcherOnThread() {
+        Dispatcher dispatcher = Dispatcher.getInstance();
+        if (dispatcher == null) {
+            throw new IllegalStateException("Must have the StrutsPrepareFilter execute before this one");
+        }
+        return dispatcher;
+    }
+
+    /**
+     * Create a {@link Dispatcher} 
+     */
+    private Dispatcher createDispatcher(FilterConfig filterConfig) {
+        Map<String, String> params = new HashMap<String, String>();
+        for (Enumeration e = filterConfig.getInitParameterNames(); e.hasMoreElements();) {
+            String name = (String) e.nextElement();
+            String value = filterConfig.getInitParameter(name);
+            params.put(name, value);
+        }
+        return new Dispatcher(filterConfig.getServletContext(), params);
+    }
+}
@@ -0,0 +1,117 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import org.apache.struts2.dispatcher.Dispatcher;
+import org.apache.struts2.dispatcher.mapper.ActionMapping;
+import org.apache.struts2.dispatcher.mapper.ActionMapper;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import com.opensymphony.xwork2.ActionContext;
+import com.opensymphony.xwork2.util.ValueStack;
+import com.opensymphony.xwork2.util.ValueStackFactory;
+
+import java.io.IOException;
+
+/**
+ * Contains preparation operations for a request before execution
+ */
+public class PrepareOperations {
+
+    private ServletContext servletContext;
+    private Dispatcher dispatcher;
+    private static final String STRUTS_ACTION_MAPPING_KEY = "struts.actionMapping";
+
+    public PrepareOperations(ServletContext servletContext, Dispatcher dispatcher) {
+        this.dispatcher = dispatcher;
+        this.servletContext = servletContext;
+    }
+
+    /**
+     * Creates the action context and initializes the thread local
+     */
+    public ActionContext createActionContext() {
+        ValueStack stack = dispatcher.getContainer().getInstance(ValueStackFactory.class).createValueStack();
+        ActionContext ctx = new ActionContext(stack.getContext());
+        ActionContext.setContext(ctx);
+        return ctx;
+    }
+
+    /**
+     * Assigns the dispatcher to the dispatcher thread local
+     */
+    public void assignDispatcherToThread() {
+        Dispatcher.setInstance(dispatcher);
+    }
+
+    /**
+     * Sets the request encoding and locale on the response
+     */
+    public void setEncodingAndLocale(HttpServletRequest request, HttpServletResponse response) {
+        dispatcher.prepare(request, response);
+    }
+
+    /**
+     * Wraps the request with the Struts wrapper that handles multipart requests better
+     * @return The new request, if there is one
+     * @throws ServletException
+     */
+    public HttpServletRequest wrapRequest(HttpServletRequest oldRequest) throws ServletException {
+        HttpServletRequest request = oldRequest;
+        try {
+            // Wrap request first, just in case it is multipart/form-data
+            // parameters might not be accessible through before encoding (ww-1278)
+            request = dispatcher.wrapRequest(request, servletContext);
+        } catch (IOException e) {
+            String message = "Could not wrap servlet request with MultipartRequestWrapper!";
+            throw new ServletException(message, e);
+        }
+        return request;
+    }
+
+    /**
+     * Finds and optionally creates an {@link ActionMapping}.  It first looks in the current request to see if one
+     * has already been found, otherwise, it creates it and stores it in the request.  No mapping will be created in the
+     * case of static resource requests or unidentifiable requests for other servlets, for example.
+     */
+    public ActionMapping findActionMapping(HttpServletRequest request, HttpServletResponse response) {
+        ActionMapping mapping = (ActionMapping) request.getAttribute(STRUTS_ACTION_MAPPING_KEY);
+        if (mapping == null) {
+            try {
+                mapping = dispatcher.getContainer().getInstance(ActionMapper.class).getMapping(request, dispatcher.getConfigurationManager());
+                if (mapping != null) {
+                    request.setAttribute(STRUTS_ACTION_MAPPING_KEY, mapping);
+                }
+            } catch (Exception ex) {
+                dispatcher.sendError(request, response, servletContext, HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex);
+            }
+        }
+
+        return mapping;
+    }
+
+
+}
@@ -0,0 +1,89 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import org.apache.struts2.StrutsStatics;
+import org.apache.struts2.dispatcher.Dispatcher;
+import org.apache.struts2.dispatcher.mapper.ActionMapping;
+
+import javax.servlet.*;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Executes the discovered request information.  This filter requires the {@link StrutsPrepareFilter} to have already
+ * been executed in the current chain.
+ */
+public class StrutsExecuteFilter implements StrutsStatics, Filter {
+    private PrepareOperations prepare;
+    private CleanupOperations cleanup;
+    private ExecuteOperations execute;
+
+    private FilterConfig filterConfig;
+
+    public void init(FilterConfig filterConfig) throws ServletException {
+        this.filterConfig = filterConfig;
+    }
+
+    protected synchronized void lazyInit() {
+        if (execute == null) {
+            InitOperations init = new InitOperations();
+            try {
+                Dispatcher dispatcher = init.findDispatcherOnThread();
+                init.initStaticContentLoader(filterConfig, dispatcher);
+
+                prepare = new PrepareOperations(filterConfig.getServletContext(), dispatcher);
+                cleanup = new CleanupOperations(dispatcher);
+                execute = new ExecuteOperations(filterConfig.getServletContext(), dispatcher);
+            } finally {
+                cleanup.cleanupInit();
+            }
+        }
+
+    }
+
+    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
+
+        HttpServletRequest request = (HttpServletRequest) req;
+        HttpServletResponse response = (HttpServletResponse) res;
+
+        // This is necessary since we need the dispatcher instance, which was created by the prepare filter
+        lazyInit();
+
+        ActionMapping mapping = prepare.findActionMapping(request, response);
+        if (mapping == null) {
+            boolean handled = execute.executeStaticResourceRequest(request, response);
+            if (!handled) {
+                chain.doFilter(request, response);
+            }
+        } else {
+            execute.executeAction(request, response, mapping);
+        }
+    }
+
+    public void destroy() {
+        prepare = null;
+        execute = null;
+        cleanup = null;
+        filterConfig = null;
+    }
+}
@@ -0,0 +1,84 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import org.apache.struts2.StrutsStatics;
+import org.apache.struts2.dispatcher.Dispatcher;
+import org.apache.struts2.dispatcher.mapper.ActionMapping;
+
+import javax.servlet.*;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Handles both the preparation and execution phases of the Struts dispatching process.  This filter is better to use
+ * when you don't have another filter that needs access to action context information, such as Sitemesh.
+ */
+public class StrutsPrepareAndExecuteFilter implements StrutsStatics, Filter {
+    private PrepareOperations prepare;
+    private CleanupOperations cleanup;
+    private ExecuteOperations execute;
+
+    public void init(FilterConfig filterConfig) throws ServletException {
+        InitOperations init = new InitOperations();
+        try {
+            init.initLogging(filterConfig);
+            Dispatcher dispatcher = init.initDispatcher(filterConfig);
+            init.initStaticContentLoader(filterConfig, dispatcher);
+
+            prepare = new PrepareOperations(filterConfig.getServletContext(), dispatcher);
+            cleanup = new CleanupOperations(dispatcher);
+            execute = new ExecuteOperations(filterConfig.getServletContext(), dispatcher);
+        } finally {
+            cleanup.cleanupInit();
+        }
+
+    }
+
+    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
+
+        HttpServletRequest request = (HttpServletRequest) req;
+        HttpServletResponse response = (HttpServletResponse) res;
+
+        try {
+            prepare.createActionContext();
+            prepare.assignDispatcherToThread();
+            prepare.setEncodingAndLocale(request, response);
+            request = prepare.wrapRequest(request);
+            ActionMapping mapping = prepare.findActionMapping(request, response);
+            if (mapping == null) {
+                boolean handled = execute.executeStaticResourceRequest(request, response);
+                if (!handled) {
+                    chain.doFilter(request, response);
+                }
+            } else {
+                execute.executeAction(request, response, mapping);
+            }
+        } finally {
+            cleanup.cleanupRequest();
+        }
+    }
+
+    public void destroy() {
+        cleanup.cleanupDispatcher();
+    }
+}
@@ -0,0 +1,73 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.struts2.dispatcher.filter;
+
+import org.apache.struts2.StrutsStatics;
+import org.apache.struts2.dispatcher.Dispatcher;
+
+import javax.servlet.*;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Prepares the request for execution by a later {@link StrutsExecuteFilter} filter instance.
+ */
+public class StrutsPrepareFilter implements StrutsStatics, Filter {
+    private PrepareOperations prepare;
+    private CleanupOperations cleanup;
+
+    public void init(FilterConfig filterConfig) throws ServletException {
+        InitOperations init = new InitOperations();
+        try {
+            init.initLogging(filterConfig);
+            Dispatcher dispatcher = init.initDispatcher(filterConfig);
+
+            prepare = new PrepareOperations(filterConfig.getServletContext(), dispatcher);
+            cleanup = new CleanupOperations(dispatcher);
+        } finally {
+            cleanup.cleanupInit();
+        }
+
+    }
+
+    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
+
+        HttpServletRequest request = (HttpServletRequest) req;
+        HttpServletResponse response = (HttpServletResponse) res;
+
+        try {
+            prepare.createActionContext();
+            prepare.assignDispatcherToThread();
+            prepare.setEncodingAndLocale(request, response);
+            request = prepare.wrapRequest(request);
+            prepare.findActionMapping(request, response);
+
+            chain.doFilter(request, response);
+        } finally {
+            cleanup.cleanupRequest();
+        }
+    }
+
+    public void destroy() {
+        cleanup.cleanupDispatcher();
+    }
+}
@@ -0,0 +1,70 @@
+/*
+ * $Id: DefaultActionSupport.java 651946 2008-04-27 13:41:38Z apetrelli $
+ *
+ * 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.
+ */
+/**
+ * This package contains a reimagining of the traditional Struts filter dispatchers.  Each specific deployment has
+ * their own filters to prevent confusion.  In addition, the operations have been explicitly pulled into *Operations
+ * objects that try to document through method naming what is happening at every step.  Here are a few common use
+ * cases and how you would manage the Struts deployment:
+ *
+ * <h3>Simple Dispatcher</h3>
+ * <pre>
+ * &lt;filter&gt;
+ *     &lt;filter-name&gt;struts2&lt;/filter-name&gt;
+ *     &lt;filter-class&gt;org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter&lt;/filter-class&gt;
+ * &lt;/filter&gt;
+ *
+ * &lt;filter-mapping&gt;
+ *     &lt;filter-name&gt;struts2&lt;/filter-name&gt;
+ *     &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ * &lt;/filter-mapping&gt;
+ * </pre>
+ *
+ * <h3>Deployment with Sitemesh</h3>
+ * <pre>
+ * &lt;filter&gt;
+ *     &lt;filter-name&gt;struts2-prepare&lt;/filter-name&gt;
+ *     &lt;filter-class&gt;org.apache.struts2.dispatcher.filter.StrutsPrepareFilter&lt;/filter-class&gt;
+ * &lt;/filter&gt;
+ * &lt;filter&gt;
+ *     &lt;filter-name&gt;sitemesh&lt;/filter-name&gt;
+ *     &lt;filter-class&gt;com.opensymphony.module.sitemesh.filter.PageFilter&lt;/filter-class&gt;
+ * &lt;/filter&gt;
+ * &lt;filter&gt;
+ *     &lt;filter-name&gt;struts2-execute&lt;/filter-name&gt;
+ *     &lt;filter-class&gt;org.apache.struts2.dispatcher.filter.StrutsExecuteFilter&lt;/filter-class&gt;
+ * &lt;/filter&gt;
+ *
+ * &lt;filter-mapping&gt;
+ *     &lt;filter-name&gt;struts2-prepare&lt;/filter-name&gt;
+ *     &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ * &lt;/filter-mapping&gt;
+ * &lt;filter-mapping&gt;
+ *     &lt;filter-name&gt;sitemesh&lt;/filter-name&gt;
+ *     &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ * &lt;/filter-mapping&gt;
+ * &lt;filter-mapping&gt;
+ *     &lt;filter-name&gt;struts2-execute&lt;/filter-name&gt;
+ *     &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ * &lt;/filter-mapping&gt;
+ * </pre>
+ * 
+ */
+package org.apache.struts2.dispatcher.filter;