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* $Id$
*
* 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.mapper;
import java.net.URLDecoder;
import java.util.HashMap;
import java.util.StringTokenizer;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts2.StrutsConstants;
import com.opensymphony.xwork2.config.ConfigurationManager;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
/**
* <!-- START SNIPPET: description -->
*
* Improved restful action mapper that adds several ReST-style improvements to
* action mapping, but supports fully-customized URL's via XML. The two primary
* ReST enhancements are:
* <ul>
* <li>If the method is not specified (via '!' or 'method:' prefix), the method is
* "guessed" at using ReST-style conventions that examine the URL and the HTTP
* method.</li>
* <li>Parameters are extracted from the action name, if parameter name/value pairs
* are specified using PARAM_NAME/PARAM_VALUE syntax.
* </ul>
* <p>
* These two improvements allow a GET request for 'category/action/movie/Thrillers' to
* be mapped to the action name 'movie' with an id of 'Thrillers' with an extra parameter
* named 'category' with a value of 'action'. A single action mapping can then handle
* all CRUD operations using wildcards, e.g.
* </p>
* <pre>
* <action name="movie/*" className="app.MovieAction">
* <param name="id">{0}</param>
* ...
* </action>
* </pre>
* <p>
* This mapper supports the following parameters:
* </p>
* <ul>
* <li><code>struts.mapper.idParameterName</code> - If set, this value will be the name
* of the parameter under which the id is stored. The id will then be removed
* from the action name. This allows restful actions to not require wildcards.
* </li>
* </ul>
* <p>
* The following URL's will invoke its methods:
* </p>
* <ul>
* <li><code>GET: /movie/ => method="index"</code></li>
* <li><code>GET: /movie/Thrillers => method="view", id="Thrillers"</code></li>
* <li><code>GET: /movie/Thrillers!edit => method="edit", id="Thrillers"</code></li>
* <li><code>GET: /movie/new => method="editNew"</code></li>
* <li><code>POST: /movie/ => method="create"</code></li>
* <li><code>PUT: /movie/Thrillers => method="update", id="Thrillers"</code></li>
* <li><code>DELETE: /movie/Thrillers => method="remove", id="Thrillers"</code></li>
* </ul>
* <p>
* To simulate the HTTP methods PUT and DELETE, since they aren't supported by HTML,
* the HTTP parameter "__http_method" will be used.
* </p>
* <p>
* The syntax and design for this feature was inspired by the ReST support in Ruby on Rails.
* See <a href="http://ryandaigle.com/articles/2006/08/01/whats-new-in-edge-rails-simply-restful-support-and-how-to-use-it">
* http://ryandaigle.com/articles/2006/08/01/whats-new-in-edge-rails-simply-restful-support-and-how-to-use-it
* </a>
* </p>
*
* <!-- END SNIPPET: description -->
*/
public class Restful2ActionMapper extends DefaultActionMapper {
protected static final Logger LOG = LoggerFactory.getLogger(Restful2ActionMapper.class);
public static final String HTTP_METHOD_PARAM = "__http_method";
private String idParameterName = null;
public Restful2ActionMapper() {
setSlashesInActionNames("true");
}
/*
* (non-Javadoc)
*
* @see org.apache.struts2.dispatcher.mapper.ActionMapper#getMapping(javax.servlet.http.HttpServletRequest)
*/
public ActionMapping getMapping(HttpServletRequest request, ConfigurationManager configManager) {
if (!isSlashesInActionNames()) {
throw new IllegalStateException("This action mapper requires the setting 'slashesInActionNames' to be set to 'true'");
}
ActionMapping mapping = super.getMapping(request, configManager);
if (mapping == null) {
return null;
}
String actionName = mapping.getName();
String id = null;
// Only try something if the action name is specified
if (actionName != null && actionName.length() > 0) {
int lastSlashPos = actionName.lastIndexOf('/');
if (lastSlashPos > -1) {
id = actionName.substring(lastSlashPos+1);
}
// If a method hasn't been explicitly named, try to guess using ReST-style patterns
if (mapping.getMethod() == null) {
if (lastSlashPos == actionName.length() -1) {
// Index e.g. foo/
if (isGet(request)) {
mapping.setMethod("index");
// Creating a new entry on POST e.g. foo/
} else if (isPost(request)) {
mapping.setMethod("create");
}
} else if (lastSlashPos > -1) {
// Viewing the form to create a new item e.g. foo/new
if (isGet(request) && "new".equals(id)) {
mapping.setMethod("editNew");
// Viewing an item e.g. foo/1
} else if (isGet(request)) {
mapping.setMethod("view");
// Removing an item e.g. foo/1
} else if (isDelete(request)) {
mapping.setMethod("remove");
// Updating an item e.g. foo/1
} else if (isPut(request)) {
mapping.setMethod("update");
}
}
if (idParameterName != null && lastSlashPos > -1) {
actionName = actionName.substring(0, lastSlashPos);
}
}
if (idParameterName != null && id != null) {
if (mapping.getParams() == null) {
mapping.setParams(new HashMap<String, Object>());
}
mapping.getParams().put(idParameterName, id);
}
// Try to determine parameters from the url before the action name
int actionSlashPos = actionName.lastIndexOf('/', lastSlashPos - 1);
if (actionSlashPos > 0 && actionSlashPos < lastSlashPos) {
String params = actionName.substring(0, actionSlashPos);
HashMap<String,String> parameters = new HashMap<String,String>();
try {
StringTokenizer st = new StringTokenizer(params, "/");
boolean isNameTok = true;
String paramName = null;
String paramValue;
while (st.hasMoreTokens()) {
if (isNameTok) {
paramName = URLDecoder.decode(st.nextToken(), "UTF-8");
isNameTok = false;
} else {
paramValue = URLDecoder.decode(st.nextToken(), "UTF-8");
if ((paramName != null) && (paramName.length() > 0)) {
parameters.put(paramName, paramValue);
}
isNameTok = true;
}
}
if (parameters.size() > 0) {
if (mapping.getParams() == null) {
mapping.setParams(new HashMap<String, Object>());
}
mapping.getParams().putAll(parameters);
}
} catch (Exception e) {
if (LOG.isWarnEnabled()) {
LOG.warn("Unable to determine parameters from the url", e);
}
}
mapping.setName(actionName.substring(actionSlashPos+1));
}
}
return mapping;
}
protected boolean isGet(HttpServletRequest request) {
return "get".equalsIgnoreCase(request.getMethod());
}
protected boolean isPost(HttpServletRequest request) {
return "post".equalsIgnoreCase(request.getMethod());
}
protected boolean isPut(HttpServletRequest request) {
if ("put".equalsIgnoreCase(request.getMethod())) {
return true;
} else {
return isPost(request) && "put".equalsIgnoreCase(request.getParameter(HTTP_METHOD_PARAM));
}
}
protected boolean isDelete(HttpServletRequest request) {
if ("delete".equalsIgnoreCase(request.getMethod())) {
return true;
} else {
return isPost(request) && "delete".equalsIgnoreCase(request.getParameter(HTTP_METHOD_PARAM));
}
}
public String getIdParameterName() {
return idParameterName;
}
@Inject(required=false,value=StrutsConstants.STRUTS_ID_PARAMETER_NAME)
public void setIdParameterName(String idParameterName) {
this.idParameterName = idParameterName;
}
}