jstl是el表达式的扩展
使用jstl需要添加jar包
package com.test.servlet;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.test.pojo.Student;
/**
* Servlet implementation class TestJstlServlet
*/
@WebServlet("/TestJstlServlet")
public class TestJstlServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public TestJstlServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//response.getWriter().append("Served at: ").append(request.getContextPath());
request.setAttribute("store_num", 50);
request.setAttribute("price", 500);
List<Student> list=new ArrayList<Student>();
list.add(new Student(1,"daimenglaoshi","jisuanji","0101"));
list.add(new Student(2,"daimenglaoshi2","yingyu","0101"));
list.add(new Student(3,"zhangsan","jisuanji","0102"));
request.setAttribute("student_list", list);
Map<String, String> map=new HashMap<String,String>();
map.put("name", "zhangsan");
map.put("age","23");
request.setAttribute("map",map);
request.getRequestDispatcher("TestJstl.jsp").forward(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${store_num>10}">
库存充足
</c:if>
<c:if test="${store_num<=10}">
库存不足
</c:if>
<c:choose>
<c:when test="${price>1000}"> 太贵</c:when>
<c:when test="${price>500}"> 买得起</c:when>
<c:otherwise>太便宜了 不买了</c:otherwise>
</c:choose>
<c:forEach var="student" items="${student_list}" >
${student.sname}<br/>
</c:forEach>
<c:forEach var="item" items="${map}">
${item.key} ${item.value}<br/>
</c:forEach>
</body>
</html>
package com.test.pojo;
//琛ㄦ槧灏勭被
public class Student {
private int sid;
public int getSid() {
return sid;
}
public void setSid(int sid) {
this.sid = sid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
public String getStu_class() {
return stu_class;
}
public void setStu_class(String stu_class) {
this.stu_class = stu_class;
}
private String sname;
private String major;
private String stu_class;
public Student()
{
}
public Student(int sid,String sname,String major,String stu_class)
{
this.sid=sid;
this.sname=sname;
this.major=major;
this.stu_class=stu_class;
}
}