Jsp/Struts国际化处理

Introduction:
For: Make web app internationalization.
Skill: Jsp Tag Library.
注: 本文讲解的是struts内部的国际化详细解析，从底层的tag搭建

1. Create Tag
src\com\taglibs\messageTag.java

package com.taglibs;import java.io.BufferedInputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.util.Enumeration;import java.util.Locale;import java.util.Properties;import java.util.ResourceBundle;import javax.servlet.jsp.JspException;import javax.servlet.jsp.JspTagException;import javax.servlet.jsp.JspWriter;import javax.servlet.jsp.tagext.TagSupport;public class messageTag extends TagSupport{private String key="";private ResourceBundle bundle;// default.propertiesprivate Locale locale=Locale.SIMPLIFIED_CHINESE;private String name="";private String property="";private String scope="";private String arg0="";private String arg1="";private String arg2="";private String arg3="";private String arg4="";private String arg5="";private static String ProfileName = "language";@Overridepublic int doStartTag() throws JspException{super.doStartTag();try{JspWriter out = pageContext.getOut();//Locale locale = new Locale("zh", "CN"); if(bundle==null)bundle  = ResourceBundle.getBundle(ProfileName, locale); String format = bundle.getString(key);String value = String.format(format, arg0, arg1, arg2, arg3, arg4, arg5 );if(value==null)out.print(key);elseout.print(value);}catch(IOException e){throw new JspTagException(e.getMessage());}return SKIP_BODY;}public static String getProfileName(){return ProfileName;}public static void setProfileName(String profileName){ProfileName = profileName;}public void setBundle(ResourceBundle bundle){this.bundle = bundle;}public ResourceBundle getBundle(){return bundle;}public void setBundle(String language){this.locale = new Locale(language);this.bundle = ResourceBundle.getBundle(ProfileName, locale); /* *  ResourceBundle bundle = ResourceBundle.getBundle(PROPERTIES_FILE_NAME, Locale.ENGLISH);这行代码初始化了一个ResourceBundle，Locale.ENGLISH用于指明本地化情况，因此会从"property_en.properties"中去读取配置项。如果是Locale.CHINA，则会从property_zh.properties中读取。这种机制使得程序的本地化变得简单。 */}public Locale getLocale(){return locale;}public void setLocale(Locale locale){this.locale = locale;}public String getKey(){return key;}public void setKey(String key){this.key = key;}public String getName(){return name;}public void setName(String name){this.name = name;}public String getProperty(){return property;}public void setProperty(String property){this.property = property;}public String getScope(){return scope;}public void setScope(String scope){this.scope = scope;}public String getArg0(){return arg0;}public void setArg0(String arg0){this.arg0 = arg0;}public String getArg1(){return arg1;}public void setArg1(String arg1){this.arg1 = arg1;}public String getArg2(){return arg2;}public void setArg2(String arg2){this.arg2 = arg2;}public String getArg3(){return arg3;}public void setArg3(String arg3){this.arg3 = arg3;}public String getArg4(){return arg4;}public void setArg4(String arg4){this.arg4 = arg4;}public String getArg5(){return arg5;}public void setArg5(String arg5){this.arg5 = arg5;}public static String readValue(String filePath,String key) {Properties props = new Properties();File f = new File(filePath);if(!f.exists()){System.out.println("file not exist!");return null;}try {InputStream in = new BufferedInputStream (new FileInputStream(filePath));props.load(in);String value = props.getProperty (key);System.out.println(key+"="+value);return value;} catch (Exception e) {e.printStackTrace();return null;}}//读取properties的全部信息public static void readProperties(String filePath) {Properties props = new Properties();try {InputStream in = new BufferedInputStream (new FileInputStream(filePath));props.load(in);Enumeration en = props.propertyNames();while (en.hasMoreElements()) {String key = (String) en.nextElement();String Property = props.getProperty (key);System.out.println(key+Property);}} catch (Exception e) {e.printStackTrace();}}//写入properties信息public static void writeProperties(String filePath,String parameterName,String parameterValue) {Properties prop = new Properties();try {InputStream fis = new FileInputStream(filePath);prop.load(fis);OutputStream fos = new FileOutputStream(filePath);prop.setProperty(parameterName, parameterValue);prop.store(fos, "Update '" + parameterName + "' value");} catch (IOException e) {System.err.println("Visit "+filePath+" for updating "+parameterName+" value error");}}}

2. Config tld file 
WEB-INF/struts-bean.tld

<?xml version="1.0" encoding="UTF-8" ?><taglib><tlib-version>1.0</tlib-version><jsp-version>1.2</jsp-version><shot-name>messageTag</shot-name><description>my struts lib!</description><tag><description></description><name>message</name><tag-class>com.taglibs.messageTab</tag-class><bodycontent>empty</bodycontent><attribute><name>arg0</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>arg1</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>arg2</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>arg3</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>arg4</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>bundle</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>key</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>locale</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>name</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>property</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute><attribute><name>scope</name><required>false</required><rtexprvalue>true</rtexprvalue></attribute></tag></taglib>

3. 定义资源文件
在/WEB-INF/classes下面添加UTF-8资源束文件。每一个资源文件是“键－值”对的集合。在JSP页面里面可以通过键来找到相应的数据值。本例子的文件名是ApplicationResources，所以相应的资源文件束是(包括e文，简体中文，繁体中文)
language.properties : 默认资源文件。当在其他资源文件里面找不到某个资源的时候，就使用该资源文件里面的定义。
language_zh_CN.properties：简体中文资源文件。
language_zh_TW.properties：繁体中文资源文件。
资源文件的格式为：默认资源文件名_语言_国别.properties。其中每个文件都是通过%JAVA_HONE%/BIN/native2ascii.exe工具转换而来。


1) 准备文件
//ApplicationResources.properties ；默认资源文件，通常里面的内容是英文的。
label.username=USERNAME :
label.password=PASSWORD :
label.login.submit=Submit


//ApplicationResources_zh_CN.bak ；简体中文的资源文件。里面的内容是中文的。它需要工具将其中的内容处理成UTF-8
label.username=用户名 :
label.password=密  码 :
label.login.submit=登录


//ApplicationResources_zh_TW.bak : 繁体中文的资源文件。里面的内容是中文的。它需要工具将其中的内容处理成UTF-8,下面的内容是繁体码。
label.username=ノめ?W :
label.password=ノめ?W :
label.login.submit=めノ?W 

2)准备完成以后，使用如下的命令创建UTF-8资源文件束
native2ascii -encoding gb2312 ApplicationResources_zh_CN.bak ApplicationResources_zh_CN.properties
native2ascii -encoding big5 Applica tionResources_zh_TW.bak ApplicationResources_zh_TW.properties

3. Test the taglib
index.jsp

<%@ page language="java" contentType="text/html;charset=GBK" %><%@ page isELIgnored="false" %><%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean"%><body><form name=myform action="test.do" ><bean:message key="label.username" bundle="en"/><input type="text" id="userName"> <br><bean:message key="label.password" bundle="en"/><input type="text" id="passWord"> <br><button onclick="myform.submit();"><bean:message key="label.login.submi" bundle="en"/></button></form><body>

4. Config for Web App1)定义web.xml的动ActionServlet的参数

<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>application</param-name>    <param-value>language</param-value> <!-- 默认资源文件名 -->  </init-param>  <load-on-startup>2</load-on-startup></servlet>

可以在IE的工具->Internet选项->语言的地方，来选择，定义IE的语言。

5. 表单的数据的处理。
对于表单数据的处理，我们是通过添加一个Filter来实现的。所有提交的请求，都需要做字符处理。然后在web.xml里面定义该Filter。这样我们就不需要在程序里面做任何的字符处理。
1) 定义Filter。下面是一个例子。

package com.webapps.commons;import java.io.*;import javax.servlet.*;public class CharsetEncodingFilter implements Filter{  private FilterConfig config = null;  private String defaultEncode = "UTF-8";  public void init(FilterConfig config) throws ServletException {    this.config = config;    if(config.getInitParameter("Charset")!=null){        defaultEncode=config.getInitParameter("Charset");    }  }  public void destroy() {    this.config = null;  }  public void doFilter(ServletRequest request, ServletResponse response,                       FilterChain chain) throws IOException, ServletException {    ServletRequest srequest=request;    srequest.setCharacterEncoding(defaultEncode);    chain.doFilter(srequest,response);  }}

2) 在web.xml里面声明使用该Filter

<filter>  <filter-name>Character Encoding</filter-name>  <filter-class>com.webapps.commons.CharsetEncodingFilter</filter-class></filter><filter-mapping>  <filter-name>Character Encoding</filter-name>  <url-pattern>/*</url-pattern></filter-mapping>