软件国际化及监听器

 
 I18N:
  Locale代表本地环境
   Locale (String lang)
   Locale (String lang,String country)
   Locale (String lang,String country,String variant)
   
  ResourceBundle加载不同的的资源文件
  
  
   1.public class TestI18N {
   
    /**
     * @param args
     */
    public static void main(String[] args)
    {
     // TODO Auto-generated method stub
     Locale locale=new Locale("ad","da");
     ResourceBundle rb=ResourceBundle.getBundle("lang", locale);
     String userName=rb.getString("username");
     String userPassword=rb.getString("userPassword");
     System.out.println(userName+"             "+userPassword);
    }
   
    }
   2.file文件命名格式：lang_zh_CN.properties
                       lang.properties            //默认的
                       lang_zh_TW.properties
                      
   public class I18NTag extends TagSupport
   {
    private String key;
   
    public String getKey() {
     return key;
    }
   
    public void setKey(String key) {
     this.key = key;
    }
   
    @Override
    public int doEndTag() throws JspException {
     // TODO Auto-generated method stub
     return super.doEndTag();
    }
   
    @Override
    public int doStartTag() throws JspException {
     // TODO Auto-generated method stub
     Locale locale=((HttpServletRequest)this.pageContext.getRequest()).getLocale

();
     JspWriter out=this.pageContext.getOut();
     ResourceBundle rb=ResourceBundle.getBundle("lang", locale);
     String v=rb.getString(key);
     try
     {
      out.write(v);
     }
     catch (IOException e)
     {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }
   
   
     return this.SKIP_BODY;
    }
    
   }
            
    自定义标签 .tld文件；
     <?xml version="1.0" encoding="UTF-8" ?>

   <taglib xmlns="http://java.sun.com/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

http://java.sun.com/xml/ns/javaee/web-jsptaglibrary_2_1.xsd"
       version="2.1">
      
     <description>Hello I18N</description>
     <display-name>JSTL core</display-name>
     <tlib-version>1.1</tlib-version>
     <short-name>my</short-name>
     <uri>http://java.ming.com/my</uri>
   
   
   
     <tag>
       <description>
     I18N--International
       </description>
       <name>inal</name>
       <tag-class>com.xasxt.action.I18NTag</tag-class>
       <body-content>JSP</body-content>
       <attribute>
           <description>
      key
           </description>
           <name>key</name>
           <required>true</required>
           <rtexprvalue>true</rtexprvalue>
    <type>boolean</type>
       </attribute>
     </tag>
   
   
   
   
   </taglib>     
   
   
 监听器：
  对session监听的类需要实现HttpSessionListener接口，对session属性监听的类需要实现

HttpSessionAttributeListener接口
  相应的类必须在web.xml配置<Listener>
  
  对application监听的类需要实现ServletContextListener接口，对session属性监听的类需要实现

ServletContextAttributeListener接口
  相应的类必须在web.xml配置<Listener>
 获取application对象：
  ServletContext application=this.getServl