struts标签+jstl标签之国际化实例

 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。