/*
* Copyright 2002-2006,2009 The Apache Software Foundation.
*
* Licensed 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 com.opensymphony.xwork2.interceptor;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.util.LocalizedTextUtil;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import java.util.Locale;
import java.util.Map;
/**
* <!-- START SNIPPET: description -->
* <p/>
* An interceptor that handles setting the locale specified in a session as the locale for the current action request.
* In addition, this interceptor will look for a specific HTTP request parameter and set the locale to whatever value is
* provided. This means that this interceptor can be used to allow for your application to dynamically change the locale
* for the user's session or, alternatively, only for the current request (since XWork 2.1.3).
* This is very useful for applications that require multi-lingual support and want the user to
* be able to set his or her language preference at any point. The locale parameter is removed during the execution of
* this interceptor, ensuring that properties aren't set on an action (such as request_locale) that have no typical
* corresponding setter in your action.
* <p/>
* <p/>For example, using the default parameter name, a request to <b>foo.action?request_locale=en_US</b>, then the
* locale for US English is saved in the user's session and will be used for all future requests.
* <p/>
if there is no locale set (for example with the first visit), the interceptor uses the browser locale.
* <p/>
* <!-- END SNIPPET: description -->
* <p/>
* <p/> <u>Interceptor parameters:</u>
* <p/>
* <!-- START SNIPPET: parameters -->
* <p/>
* <ul>
* <p/>
* <li>parameterName (optional) - the name of the HTTP request parameter that dictates the locale to switch to and save
* in the session. By default this is <b>request_locale</b></li>
* <p/>
* <li>requestOnlyParameterName (optional) - the name of the HTTP request parameter that dictates the locale to switch to
* for the current request only, without saving it in the session. By default this is <b>request_only_locale</b></li>
* <p/>
* <li>attributeName (optional) - the name of the session key to store the selected locale. By default this is
* <b>WW_TRANS_I18N_LOCALE</b></li>
* <p/>
* </ul>
* <p/>
* <!-- END SNIPPET: parameters -->
* <p/>
* <p/> <u>Extending the interceptor:</u>
* <p/>
* <p/>
* <p/>
* <!-- START SNIPPET: extending -->
* <p/>
* There are no known extensions points for this interceptor.
* <p/>
* <!-- END SNIPPET: extending -->
* <p/>
* <p/> <u>Example code:</u>
* <p/>
* <pre>
* <!-- START SNIPPET: example -->
* <action name="someAction" class="com.examples.SomeAction">
* <interceptor-ref name="i18n"/>
* <interceptor-ref name="basicStack"/>
* <result name="success">good_result.ftl</result>
* </action>
* <!-- END SNIPPET: example -->
* </pre>
*
* @author Aleksei Gopachenko
*/
public class I18nInterceptor extends AbstractInterceptor {
private static final long serialVersionUID = 2496830135246700300L;
protected static final Logger LOG = LoggerFactory.getLogger(I18nInterceptor.class);
public static final String DEFAULT_SESSION_ATTRIBUTE = "WW_TRANS_I18N_LOCALE";
public static final String DEFAULT_PARAMETER = "request_locale";
public static final String DEFAULT_REQUESTONLY_PARAMETER = "request_only_locale";
protected String parameterName = DEFAULT_PARAMETER;
protected String requestOnlyParameterName = DEFAULT_REQUESTONLY_PARAMETER;
protected String attributeName = DEFAULT_SESSION_ATTRIBUTE;
// Request-Only = None
protected enum Storage { SESSION, NONE }
public I18nInterceptor() {
if (LOG.isDebugEnabled()) {
LOG.debug("new I18nInterceptor()");
}
}
public void setParameterName(String parameterName) {
this.parameterName = parameterName;
}
public void setRequestOnlyParameterName(String requestOnlyParameterName) {
this.requestOnlyParameterName = requestOnlyParameterName;
}
public void setAttributeName(String attributeName) {
this.attributeName = attributeName;
}
@Override
public String intercept(ActionInvocation invocation) throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug("intercept '#0/#1' {",
invocation.getProxy().getNamespace(), invocation.getProxy().getActionName());
}
LocaleFinder localeFinder = new LocaleFinder(invocation);
Locale locale = getLocaleFromParam(localeFinder.getRequestedLocale());
locale = storeLocale(invocation, locale, localeFinder.getStorage());
saveLocale(invocation, locale);
if (LOG.isDebugEnabled()) {
LOG.debug("before Locale=#0", invocation.getStack().findValue("locale"));
}
final String result = invocation.invoke();
if (LOG.isDebugEnabled()) {
LOG.debug("after Locale=#0", invocation.getStack().findValue("locale"));
LOG.debug("intercept } ");
}
return result;
}
/**
* Store the locale to the chosen storage, like f. e. the session
*
* @param invocation the action invocation
* @param locale the locale to store
* @param storage the place to store this locale (like Storage.SESSSION.toString())
*/
protected Locale storeLocale(ActionInvocation invocation, Locale locale, String storage) {
//save it in session
Map<String, Object> session = invocation.getInvocationContext().getSession();
if (session != null) {
synchronized (session) {
if (locale == null) {
storage = Storage.NONE.toString();
locale = readStoredLocale(invocation, session);
}
if (Storage.SESSION.toString().equals(storage)) {
session.put(attributeName, locale);
}
}
}
return locale;
}
protected class LocaleFinder {
protected String storage = Storage.SESSION.toString();
protected Object requestedLocale = null;
protected ActionInvocation actionInvocation = null;
protected LocaleFinder(ActionInvocation invocation) {
actionInvocation = invocation;
find();
}
protected void find() {
//get requested locale
Map<String, Object> params = actionInvocation.getInvocationContext().getParameters();
storage = Storage.SESSION.toString();
requestedLocale = findLocaleParameter(params, parameterName);
if (requestedLocale != null) {
return;
}
requestedLocale = findLocaleParameter(params, requestOnlyParameterName);
if (requestedLocale != null) {
storage = Storage.NONE.toString();
}
}
public String getStorage() {
return storage;
}
public Object getRequestedLocale() {
return requestedLocale;
}
}
/**
* Creates a Locale object from the request param, which might
* be already a Local or a String
*
* @param requestedLocale the parameter from the request
* @return the Locale
*/
protected Locale getLocaleFromParam(Object requestedLocale) {
Locale locale = null;
if (requestedLocale != null) {
locale = (requestedLocale instanceof Locale) ?
(Locale) requestedLocale :
LocalizedTextUtil.localeFromString(requestedLocale.toString(), null);
if (locale != null && LOG.isDebugEnabled()) {
LOG.debug("applied request locale=#0", locale);
}
}
return locale;
}
/**
* Reads the locale from the session, and if not found from the
* current invocation (=browser)
*
* @param invocation the current invocation
* @param session the current session
* @return the read locale
*/
protected Locale readStoredLocale(ActionInvocation invocation, Map<String, Object> session) {
Locale locale = this.readStoredLocalFromSession(invocation, session);
if (locale != null) {
return locale;
}
return this.readStoredLocalFromCurrentInvocation(invocation);
}
protected Locale readStoredLocalFromSession(ActionInvocation invocation, Map<String, Object> session) {
// check session for saved locale
Object sessionLocale = session.get(attributeName);
if (sessionLocale != null && sessionLocale instanceof Locale) {
Locale locale = (Locale) sessionLocale;
if (LOG.isDebugEnabled()) {
LOG.debug("applied session locale=#0", locale);
}
return locale;
}
return null;
}
protected Locale readStoredLocalFromCurrentInvocation(ActionInvocation invocation) {
// no overriding locale definition found, stay with current invocation (=browser) locale
Locale locale = invocation.getInvocationContext().getLocale();
if (locale != null && LOG.isDebugEnabled()) {
LOG.debug("applied invocation context locale=#0", locale);
}
return locale;
}
protected Object findLocaleParameter(Map<String, Object> params, String parameterName) {
Object requestedLocale = params.remove(parameterName);
if (requestedLocale != null && requestedLocale.getClass().isArray()
&& ((Object[]) requestedLocale).length == 1) {
requestedLocale = ((Object[]) requestedLocale)[0];
if (LOG.isDebugEnabled()) {
LOG.debug("requested_locale=#0", requestedLocale);
}
}
return requestedLocale;
}
/**
* Save the given locale to the ActionInvocation.
*
* @param invocation The ActionInvocation.
* @param locale The locale to save.
*/
protected void saveLocale(ActionInvocation invocation, Locale locale) {
invocation.getInvocationContext().setLocale(locale);
}
}