菜鸟教程　　

　　JSTL　　

　　JSTL【】：（JavaServer Pages Standard Tag Library，JSP标准标签库)是一个不断完善的开放源代码的JSP标签库

 

JSP页面使用JSTL标签

　　（一）引入JSTL的jar包

　　（二）引入JSTL的标签库

<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

　　

 

使用JSTL标签做简单数据存储

 

<%@ page language="java" contentType="text/html; charset=utf-8"    pageEncoding="utf-8"%>
      <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
      <%-- <%request.setAttribute("username","Gary"); %> --%>
      
      
      
      
      
      
      
      
      
      

 

输出

Gary 123

 

 

JSTL中条件标签和循环标签

 

<%@ page language="java" contentType="text/html; charset=utf-8"    pageEncoding="utf-8"%>
      <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><%@page import="java.util.ArrayList"%><%@page import="java.util.List"%><%@page import="java.util.HashMap"%><%@page import="java.util.Map"%><%@page import="com.Gary.model.User"%>
      
      
      
       成年人
       
      
      
          
       
            这是成年人        
        
    
       
       
            这是未成年人    
        
       
      
      
      
       这是第${i}次
       
      <%List
      
        list = new ArrayList
       
        ();list.add(new User("Gary0","0",10,"男",false));list.add(new User("Gary1","1",20,"男",false));list.add(new User("Gary2","2",30,"男",false));list.add(new User("Gary3","3",40,"男",false));list.add(new User("Gary4","4",50,"男",false));request.setAttribute("list", list);%>
        
        
             ${u.username}
         
        
       
      

 

package com.Gary.model;public class User {    private String username;    private String password;    private int age;    private String sex;    private boolean isAdmin=false;    //判断是否是管理员账号        public User(String username, String password, int age, String sex, boolean isAdmin) {        super();        this.username = username;        this.password = password;        this.age = age;        this.sex = sex;        this.isAdmin = isAdmin;    }    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;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    public boolean isAdmin() {        return isAdmin;    }    public void setAdmin(boolean isAdmin) {        this.isAdmin = isAdmin;    }    }

 

输出

成年人 这是成年人  这是第1次 这是第2次 这是第3次 这是第4次 这是第5次 这是第6次 这是第7次 这是第8次 这是第9次 这是第10次 Gary0 Gary1 Gary2 Gary3 Gary4

 

　　JSTL的if else语句

 

　　JSTL循环取出复杂数据时需要通过el表达式

<%List
     
       list = new ArrayList
      
       ();list.add(new User("Gary0","0",10,"男",false));list.add(new User("Gary1","1",20,"男",false));list.add(new User("Gary2","2",30,"男",false));list.add(new User("Gary3","3",40,"男",false));list.add(new User("Gary4","4",50,"男",false));request.setAttribute("list", list);%>
       
       
            ${u.username}