/*
* $Id: ModuleUtils.java 471754 2006-11-06 14:55:09Z husted $
*
* 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.struts.util;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.Globals;
import org.apache.struts.action.RequestProcessor;
import org.apache.struts.config.MessageResourcesConfig;
import org.apache.struts.config.ModuleConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
/**
* General purpose utility methods related to module processing.
*
* @version $Rev: 471754 $
* @since Struts 1.2
*/
public class ModuleUtils {
/**
* The Singleton instance.
*/
private static final ModuleUtils instance = new ModuleUtils();
/**
* Commons logging instance.
*/
private static final Log log = LogFactory.getLog(ModuleUtils.class);
/**
* Constructor for ModuleUtils.
*/
protected ModuleUtils() {
super();
}
/**
* Returns the Singleton instance of TagUtils.
*/
public static ModuleUtils getInstance() {
return instance;
}
/**
* Return the current ModuleConfig object stored in request, if it exists,
* null otherwise. This method can be used by plugin to retrieve the
* current module config object. If no moduleConfig is found, this means
* that the request haven't hit the server throught the struts servlet.
* The appropriate module config can be set and found with <code>{@link
* ModuleUtils#selectModule(HttpServletRequest, ServletContext)} </code>.
*
* @param request The servlet request we are processing
* @return the ModuleConfig object from request, or null if none is set in
* the request.
*/
public ModuleConfig getModuleConfig(HttpServletRequest request) {
return (ModuleConfig) request.getAttribute(Globals.MODULE_KEY);
}
/**
* Return the desired ModuleConfig object stored in context, if it exists,
* null otherwise.
*
* @param prefix The module prefix of the desired module
* @param context The ServletContext for this web application
* @return the ModuleConfig object specified, or null if not found in the
* context.
*/
public ModuleConfig getModuleConfig(String prefix, ServletContext context) {
if ((prefix == null) || "/".equals(prefix)) {
return (ModuleConfig) context.getAttribute(Globals.MODULE_KEY);
} else {
return (ModuleConfig) context.getAttribute(Globals.MODULE_KEY
+ prefix);
}
}
/**
* Return the desired ModuleConfig object stored in context, if it exists,
* otherwise return the current ModuleConfig
*
* @param prefix The module prefix of the desired module
* @param request The servlet request we are processing
* @param context The ServletContext for this web application
* @return the ModuleConfig object specified, or null if not found in the
* context.
*/
public ModuleConfig getModuleConfig(String prefix,
HttpServletRequest request, ServletContext context) {
ModuleConfig moduleConfig = null;
if (prefix != null) {
//lookup module stored with the given prefix.
moduleConfig = this.getModuleConfig(prefix, context);
} else {
//return the current module if no prefix was supplied.
moduleConfig = this.getModuleConfig(request, context);
}
return moduleConfig;
}
/**
* Return the ModuleConfig object is it exists, null otherwise.
*
* @param request The servlet request we are processing
* @param context The ServletContext for this web application
* @return the ModuleConfig object
*/
public ModuleConfig getModuleConfig(HttpServletRequest request,
ServletContext context) {
ModuleConfig moduleConfig = this.getModuleConfig(request);
if (moduleConfig == null) {
moduleConfig = this.getModuleConfig("", context);
request.setAttribute(Globals.MODULE_KEY, moduleConfig);
}
return moduleConfig;
}
/**
* Get the module name to which the specified request belong.
*
* @param request The servlet request we are processing
* @param context The ServletContext for this web application
* @return The module prefix or ""
*/
public String getModuleName(HttpServletRequest request,
ServletContext context) {
// Acquire the path used to compute the module
String matchPath =
(String) request.getAttribute(RequestProcessor.INCLUDE_SERVLET_PATH);
if (matchPath == null) {
matchPath = request.getServletPath();
}
return this.getModuleName(matchPath, context);
}
/**
* Get the module name to which the specified uri belong.
*
* @param matchPath The uri from which we want the module name.
* @param context The ServletContext for this web application
* @return The module prefix or ""
*/
public String getModuleName(String matchPath, ServletContext context) {
if (log.isDebugEnabled()) {
log.debug("Get module name for path " + matchPath);
}
String prefix = ""; // Initialize prefix before we try lookup
String[] prefixes = getModulePrefixes(context);
// Get all other possible prefixes
int lastSlash = 0; // Initialize before loop
while (prefix.equals("")
&& ((lastSlash = matchPath.lastIndexOf("/")) > 0)) {
// We may be in a non-default module. Try to get it's prefix.
matchPath = matchPath.substring(0, lastSlash);
// Match against the list of module prefixes
for (int i = 0; i < prefixes.length; i++) {
if (matchPath.equals(prefixes[i])) {
prefix = prefixes[i];
break;
}
}
}
if (log.isDebugEnabled()) {
log.debug("Module name found: "
+ (prefix.equals("") ? "default" : prefix));
}
return prefix;
}
/**
* Return the list of module prefixes that are defined for this web
* application. <strong>NOTE</strong> - the "" prefix for the default
* module is not included in this list.
*
* @param context The ServletContext for this web application.
* @return An array of module prefixes.
*/
public String[] getModulePrefixes(ServletContext context) {
return (String[]) context.getAttribute(Globals.MODULE_PREFIXES_KEY);
}
/**
* Select the module to which the specified request belongs, and add
* corresponding request attributes to this request.
*
* @param request The servlet request we are processing
* @param context The ServletContext for this web application
*/
public void selectModule(HttpServletRequest request, ServletContext context) {
// Compute module name
String prefix = getModuleName(request, context);
// Expose the resources for this module
this.selectModule(prefix, request, context);
}
/**
* Select the module to which the specified request belongs, and add
* corresponding request attributes to this request.
*
* @param prefix The module prefix of the desired module
* @param request The servlet request we are processing
* @param context The ServletContext for this web application
*/
public void selectModule(String prefix, HttpServletRequest request,
ServletContext context) {
// Expose the resources for this module
ModuleConfig config = getModuleConfig(prefix, context);
if (config != null) {
request.setAttribute(Globals.MODULE_KEY, config);
MessageResourcesConfig[] mrConfig =
config.findMessageResourcesConfigs();
for (int i = 0; i < mrConfig.length; i++) {
String key = mrConfig[i].getKey();
MessageResources resources =
(MessageResources) context.getAttribute(key + prefix);
if (resources != null) {
request.setAttribute(key, resources);
} else {
request.removeAttribute(key);
}
}
} else {
request.removeAttribute(Globals.MODULE_KEY);
}
}
}