Struts提供了国际化的功能，对于一个面向各国的系统来说，是非常有帮助的。只需要提供每个国家的语言资源包，配置后即可使用。
下面来用一个登录实例来演示一下Struts的国际化配置和显示。
创建一个login_i18n_exception的javaweb项目，引入Struts的所有jar包以及jstl.jar和standard.jar。登录界面无非就是输入用户名，密码，所以ActionForm中只需要设置2个属性即可。
package com.bjpowernode.struts;
import org.apache.struts.action.ActionForm;
/**
* 登录ActionForm，负责收集表单数据
* 表单的数据必须和ActionForm的get,set一致
* @author Longxuan
*
*/
@SuppressWarnings("serial")
public class LoginActionForm extends ActionForm {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
登录时会验证密码是否正确，需要提供异常处理，本实例显示2个异常：用户名未找到，密码错误。
package com.bjpowernode.struts;
/**
* 密码错误异常
* @author Longxuan
*
*/
@SuppressWarnings("serial")
public class PasswordErrorException extends RuntimeException {
public PasswordErrorException() {
// TODO Auto-generated constructor stub
}
public PasswordErrorException(String message) {
super(message);
// TODO Auto-generated constructor stub
}
public PasswordErrorException(Throwable cause) {
super(cause);
// TODO Auto-generated constructor stub
}
public PasswordErrorException(String message, Throwable cause) {
super(message, cause);
// TODO Auto-generated constructor stub
}
public PasswordErrorException(String message, Throwable cause,
boolean enableSuppression, boolean writableStackTrace) {
super(message, cause, enableSuppression, writableStackTrace);
// TODO Auto-generated constructor stub
}
}
package com.bjpowernode.struts;
/**
* 用户未找到异常
* @author Longxuan
*
*/
@SuppressWarnings("serial")
public class UserNotFoundException extends RuntimeException {
public UserNotFoundException() {
// TODO Auto-generated constructor stub
}
public UserNotFoundException(String message) {
super(message);
// TODO Auto-generated constructor stub
}
public UserNotFoundException(Throwable cause) {
super(cause);
// TODO Auto-generated constructor stub
}
public UserNotFoundException(String message, Throwable cause) {
super(message, cause);
// TODO Auto-generated constructor stub
}
public UserNotFoundException(String message, Throwable cause,
boolean enableSuppression, boolean writableStackTrace) {
super(message, cause, enableSuppression, writableStackTrace);
// TODO Auto-generated constructor stub
}
}
提供用户管理类，处理用户的相关操作，这里主要处理用户登录：
package com.bjpowernode.struts;
/**
* 用户管理类
* @author Longxuan
*
*/
public class UserManager {
/**
* 简单处理登录逻辑
* @param username 用户名
* @param password 密码
*/
public void login(String username,String password){
if(!"admin".equals(username)){
throw new UserNotFoundException();
}
if(! "admin".equals(password)){
throw new PasswordErrorException();
}
}
}
现在写LoginAction的处理：
package com.bjpowernode.struts;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;
/**
* 登录Action 负责取得表单数据，调用业务逻辑，返回转向信息
*
* @author Longxuan
*
*/
public class LoginAction extends Action {
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
//获取数据
LoginActionForm laf = (LoginActionForm) form;
String username = laf.getUsername();
String password = laf.getPassword();
UserManager userManager = new UserManager();
ActionMessages messages = new ActionMessages();
try {
//用户登录
userManager.login(username, password);
//获取登录成功的国际化消息
ActionMessage success= new ActionMessage("login.success",username);
messages.add("login_success_1",success);
//传递消息
this.saveMessages(request, messages);
return mapping.findForward("success");
} catch (UserNotFoundException e) {
e.printStackTrace();
//获取登录成功的国际化消息
ActionMessage error = new ActionMessage("login.user.not.found",username);
messages.add("login_error_1",error);
//传递消息
this.saveErrors(request, messages);
} catch (PasswordErrorException e) {
e.printStackTrace();
//获取登录成功的国际化消息
ActionMessage error = new ActionMessage("login.user.password.error");
messages.add("login_error_2",error);
//传递消息
this.saveErrors(request, messages);
}
return mapping.findForward("error");
}
}
来一个手动切换语言的类，方便演示：
package com.bjpowernode.struts;
import java.util.Locale;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
/**
* 完成语言的手动切换
* @author Longxuan
*
*/
public class ChangeLanguageAction extends Action {
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
//获取语言
String lang = request.getParameter("lang");
String[] split = lang.split("-");
//设置语言
Locale locale = new Locale(split[0],split[1]);
this.setLocale(request, locale);
return mapping.findForward("login");
}
}
新建国际化信息文件：创建resource包，创建 英文语言包MessageBundle_en_US.properties，中文语言包MessageBundle_zh_CN.properties，默认语言包MessageBundle.properties 这3个语言包。具体内容如下：
英文语言包和默认语言包设置成一样的：
# -- standard errors --
errors.header=<UL>
errors.prefix=<font color="red"><LI>
errors.suffix=</LI></font>
errors.footer=</UL>
login.form.field.username=User Name
login.form.field.password=Password
login.form.button.login=Login
login.success={0},Login Succedd!!
login.user.not.found=Use cant be found! Username=[{0}]
login.user.password.error=Password Error!
中文语言包：
# -- standard errors --
errors.header=<UL>
errors.prefix=<font color="red"><LI>
errors.suffix=</LI></font>
errors.footer=</UL>
login.form.field.username=\u7528\u6237\u540D
login.form.field.password=\u5BC6\u7801
login.form.button.login=\u767B\u5F55
login.success={0}\uFF0C\u767B\u5F55\u6210\u529F\uFF01
login.user.not.found=\u7528\u6237\u672A\u627E\u5230\uFF0C\u7528\u6237\u540D\uFF1A\u3010{0}\u3011
login.user.password.error=\u5BC6\u7801\u9519\u8BEF
把login.jsp源码也贴出来：
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>
<!-- ${sessionScope['org.apache.struts.action.LOCALE']}可以获取到当前设置的语言 -->
<fmt:setLocale value="${sessionScope['org.apache.struts.action.LOCALE']}" />
<fmt:setBundle basename="resource.MessageBundle" />
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>Struts登录</title>
</head>
<body>
<a href="changelang.do?lang=zh-cn">中文登录</a>|
<%--<a href="changelang.do?lang=en-us">English Login</a><br>
<html:link action="changelang.do?lang=zh-cn">中文登录</html:link>|--%>
<html:link action="changelang.do?lang=en-us">English Login</html:link>
<hr>
<html:errors />
<hr>
<h3>
struts标签读取国际化文件
</h3>
<form action="login.do" method="post">
<bean:message key="login.form.field.username" />
：
<input type="text" name="username" />
<br />
<bean:message key="login.form.field.password" />
：
<input type="text" name="password" />
<br />
<input type="submit"
value="<bean:message key="login.form.button.login"/>" />
</form>
<hr>
<h3>
jstl读取国际化文件
</h3>
<form action="login.do" method="post">
<fmt:message key="login.form.field.username" />
：
<input type="text" name="username" />
<br />
<fmt:message key="login.form.field.password" />
：
<input type="text" name="password" />
<br />
<input type="submit"
value="<fmt:message key="login.form.button.login"/>" />
</form>
</body>
</html>
login_success.jsp:
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>Insert title here</title>
</head>
<body>
<!-- message 属性设置为true，则读取message中的消息，false，则读取error中的消息。 saveMessages/saveErrors-->
<html:messages id="msg" message="true">
<bean:write name="msg"/>
</html:messages>
</body>
</html>
最后的最后，在web.xml中配置一下struts：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<init-param>
<param-name>debug</param-name>
<param-value>2</param-value>
</init-param>
<init-param>
<param-name>detail</param-name>
<param-value>2</param-value>
</init-param>
<load-on-startup>2</load-on-startup>
</servlet>
<!-- Standard Action Servlet Mapping -->
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
</web-app>
在Struts-config.xml中配置action，actionform等信息：
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
"http://jakarta.apache.org/struts/dtds/struts-config_1_2.dtd">
<struts-config>
<form-beans>
<form-bean name="loginForm" type="com.bjpowernode.struts.LoginActionForm"></form-bean>
</form-beans>
<action-mappings>
<action path="/login"
type="com.bjpowernode.struts.LoginAction"
name="loginForm"
scope="request" >
<forward name="success" path="/login_success.jsp"></forward>
<!--<forward name="error" path="/login_error.jsp"></forward>-->
<forward name="error" path="/login.jsp"></forward>
</action>
<action path="/changelang"
type="com.bjpowernode.struts.ChangeLanguageAction"
>
<forward name="login" path="/login.jsp" redirect="true"></forward>
</action>
</action-mappings>
<message-resources parameter="resource.MessageBundle"></message-resources>
</struts-config>
到此实例结束。点击这里查看效果。也可以下载源码。最后来2张效果图吧。
