最简单的Struts程序（4）---Struts应用的国际化（参考孙卫琴的struts一书）

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国际化（简称I18N）指的是在软件设计阶段，就应该使该软件具有支持多种语言和地区的功能。这样，当需要在应用中添加对一种新的语言和国家的支持时，不需要对已经有的软件返工，无需修改应用的程序代码。

1．在Struts 应用中访问Local对象

java.util.Local类是最重要的JavaI18N类，在java语言中，几乎所有对国际化和本地化的支持都依赖于这个类。

多数WEB浏览器允许你配置Local。如，对于微软的IE浏览器，可以选择【工具】|【Internet选项】命令，单击【语言】按钮，进而就可以设置选择语言了。

我们不需要做什么，在处理每一个用户请求时，ReuestProcessor类都会调用它的processLocale（）方法，processLocale（）方法把Local对象存储在session范围中。

2. 一个简单的例子，根据用户Locale的不同，显示不同的问候语。

（1）创建视图部分内容，这里只有一个JSP页面。

hello.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>

<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>

<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>

<html:html locale="true">

<head>

<html:base/>

</head>

<html:errors/><p>

<logic:present name="personbean" scope="request">

<h2>

<bean:message key="hello.jsp.page.hello"/>

<bean:write name="personbean" property="userName" />!<p>

</h2>

</logic:present>

<html:form action="/HelloWorld.do" focus="userName" >

<bean:message key="hello.jsp.prompt.person"/>

<html:text property="userName" size="16" maxlength="16"/><br>

<html:submit property="submit" >

<bean:message key="hello.jsp.page.submit"/>

</html:submit>

<html:reset property="reset" >

<bean:message key="hello.jsp.page.reset"/>

</html:reset>

</html:form><br>

<html:img pageKey="hello.jsp.page.stutsimage" altKey="hello.jsp.page.struts"/>

</body>

</html:html>

（2）创建FORMBEAN文件，

HelloForm.java

package hello;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts.action.ActionMessage;

import org.apache.struts.action.ActionErrors;

import org.apache.struts.action.ActionForm;

import org.apache.struts.action.ActionMapping;

public final class HelloForm extends ActionForm {

private String userName = null;

public String getUserName() {

return (this.userName);

}

public void setUserName(String userName) {

this.userName = userName;

}

/**

* 重新设置userName为null

public void reset(ActionMapping mapping, HttpServletRequest request) {

this.userName = null;

}

/**

* 验证userName，不能为空

public ActionErrors validate(ActionMapping mapping,

HttpServletRequest request) {

ActionErrors errors = new ActionErrors();

if ((userName == null) || (userName.length() < 1))

errors.add("username", new ActionMessage("hello.no.username.error"));

return errors;

}

（3）创建ACTION文件，

HelloAction.java

package hello;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpSession;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;

import org.apache.struts.action.ActionMessage;

import org.apache.struts.action.ActionMessages;

import org.apache.struts.action.ActionForm;

import org.apache.struts.action.ActionForward;

import org.apache.struts.action.ActionMapping;

import org.apache.struts.util.MessageResources;

public final class HelloAction extends Action {

public ActionForward execute(ActionMapping mapping,

ActionForm form,

HttpServletRequest request,

HttpServletResponse response)

throws Exception {

MessageResources messages = getResources(request);

ActionMessages errors = new ActionMessages();

String userName = (String)((HelloForm) form).getUserName();

String badUserName = "Monster";

if (userName.equalsIgnoreCase(badUserName)) {

errors.add("username", new ActionMessage("hello.dont.talk.to.monster", badUserName ));

saveErrors(request, errors);

return (new ActionForward(mapping.getInput()));

}

* Having received and validated the data submitted

* from the View, we now update the model

PersonBean pb = new PersonBean();

pb.setUserName(userName);

pb.saveToPersistentStore();

request.setAttribute(“personbean”, pb);

// Remove the Form Bean - don't need to carry values forward

request.removeAttribute(mapping.getAttribute());

// Forward control to the specified success URI

return (mapping.findForward("SayHello"));

}

（4）创建获取用户输入的userName的BEAN文件

PersonBean.java

package hello;

public class PersonBean {

private String userName = null;

public String getUserName() {

return this.userName;

}

public void setUserName(String userName) {

this.userName = userName;

}

(5)创建英文资源文件：application_en.properties

#Application Resources for the "Hello" sample application

#Application Resources that are specific to the hello.jsp file

hello.jsp.title=Hello - A first Struts program

hello.jsp.page.heading=Hello World! A first Struts application

hello.jsp.prompt.person=Please enter a UserName to say hello to :

hello.jsp.page.hello=Hello

hello.jsp.page.submit=Submit

hello.jsp.page.reset=Reset

hello.jsp.page.stutsimage=/struts-power.gif

hello.jsp.page.stuts=Powered By Struts

#Validation and error messages for HelloForm.java and HelloAction.java

hello.dont.talk.to.monster=We don't want to say hello to Monster!!!

hello.no.username.error=Please enter a <i>UserName</i> to say hello to!

（6）创建中文资源文件：application_temp.properties

#Application Resources for the "Hello" sample application

#Application Resources that are specific to the hello.jsp file

hello.jsp.title=Hello - 第一个Struts应用

hello.jsp.page.heading=Hello World! 第一个Struts应用

hello.jsp.prompt.person=请输入你想打招呼的用户名:

hello.jsp.page.hello=你好

hello.jsp.page.submit=提交

hello.jsp.page.reset=复位

hello.jsp.page.stutsimage=/struts-power-ch.gif

hello.jsp.page.stuts=基于Struts技术

#Validation and error messages for HelloForm.java and HelloAction.java

hello.dont.talk.to.monster=我们不想对Monster打招呼!!!

hello.no.username.error=请输入你想打招呼的<i>用户名</i>!

接着对临时资源文件进行编码转换，使用encode.bat即可搞定。生成的文件名为：application_zh_CN.properties。

#Application Resources for the "Hello" sample application

#Application Resources that are specific to the hello.jsp file

hello.jsp.title=Hello - /u7b2c/u4e00/u4e2aStruts/u5e94/u7528

hello.jsp.page.heading=Hello World! /u7b2c/u4e00/u4e2aStruts/u5e94/u7528

hello.jsp.prompt.person=/u8bf7/u8f93/u5165/u4f60/u60f3/u6253/u62db/u547c/u7684/u7528/u6237/u540d:

hello.jsp.page.hello=/u4f60/u597d

hello.jsp.page.submit=/u63d0/u4ea4

hello.jsp.page.reset=/u590d/u4f4d

hello.jsp.page.stutsimage=/struts-power-ch.gif

hello.jsp.page.stuts=/u57fa/u4e8eStruts/u6280/u672f

#Validation and error messages for HelloForm.java and HelloAction.java

hello.dont.talk.to.monster=/u6211/u4eec/u4e0d/u60f3/u5bf9Monster/u6253/u62db/u547c!!!

hello.no.username.error=/u8bf7/u8f93/u5165/u4f60/u60f3/u6253/u62db/u547c/u7684<i>/u7528/u6237/u540d</i>!

3. 采用Servlet过滤器设置请求数据的字符编码

SetCharacterEncodingFilter.java

import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.UnavailableException;

public class SetCharacterEncodingFilter implements Filter {

/**

* Take this filter out of service.

public void destroy() {

}

/**

* Select and set (if specified) the character encoding to be used to

* interpret request parameters for this request.

public void doFilter(ServletRequest request, ServletResponse response,

FilterChain chain)throws IOException, ServletException {

request.setCharacterEncoding("UTF-8");

// 传递控制到下一个过滤器

chain.doFilter(request, response);

}

public void init(FilterConfig filterConfig) throws ServletException {

}

4. 设置struts-config.xml

<?xml version="1.0" encoding="ISO-8859-1" ?>

<!DOCTYPE struts-config PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 1.1//EN"

"http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">

<struts-config>

<form-beans>

<form-bean name="HelloForm" type="hello.HelloForm"/>

</form-beans>

<action-mappings>

<action path = "/HelloWorld"

type = "hello.HelloAction"

name = "HelloForm"

scope = "request"

validate = "true"

input = "/hello.jsp">

</action>

</action-mappings>

<message-resources parameter="hello.application_en"/>

</struts-config>

5. 设置web.xml文件

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE web-app

PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"

"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">

<web-app>

<display-name>HelloApp Struts Application</display-name>

<filter-name>Set Character Encoding</filter-name>

<filter-class>SetCharacterEncodingFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>Set Character Encoding</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

<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>

<load-on-startup>2</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>action</servlet-name>

<url-pattern>*.do</url-pattern>

</servlet-mapping>

<welcome-file-list>

<welcome-file>hello.jsp</welcome-file>

</welcome-file-list>

<taglib-uri>/WEB-INF/struts-bean.tld</taglib-uri>

<taglib-location>/WEB-INF/struts-bean.tld</taglib-location>

</taglib>

<taglib-uri>/WEB-INF/struts-html.tld</taglib-uri>

<taglib-location>/WEB-INF/struts-html.tld</taglib-location>

</taglib>

<taglib-uri>/WEB-INF/struts-logic.tld</taglib-uri>

<taglib-location>/WEB-INF/struts-logic.tld</taglib-location>

</taglib>

</web-app>