今天搞一下el和jstl表达式

maven项目

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html >
<html>
    <head>
        <title>Insert title here</title>
    </head>
    <body>
        <a href="./DataServlet">链接</a>
    </body>
</html>

DataServlet

package com.jd.area.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jd.vo.Area;

public class DataServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setAttribute("age", 12);
        request.setAttribute("area", new Area("a","b","c","d"));
        request.setAttribute("names", new String[] {"1","2","3","4"});
        request.getRequestDispatcher("target.jsp").forward(request, response);
    }
}

Area类

package com.jd.vo;

public class Area {
    private String id;
    private String name;
    private String code;
    private String parentCode;


    public Area(String id, String name, String code, String parentCode) {
        this.id = id;
        this.name = name;
        this.code = code;
        this.parentCode = parentCode;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public String getParentCode() {
        return parentCode;
    }
    public void setParentCode(String parentCode) {
        this.parentCode = parentCode;
    }


}

target.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="zzu" %>
<!DOCTYPE html >
<html>
    <head>
        <title>Insert title here</title>
    </head>
    <body>
        <!--基本数据类型或String类型${key}  -->
        ${age}

        <!--自定义类型：${key.成员变量}  -->
        ${area.id} ${area.name} ${area.code} ${area.parentCode}

        <!--数组：${数组名[索引]}  -->
        ${names[0]}
        <!-- 数组遍历 -->  
        <zzu:forEach var="name" items="${names }">
            ${name }
        </zzu:forEach> 
    </body>
</html>

结果

12 a b c d 1 1 2 3 4

补充一下

web.xml文件还是需要2.5及以上版本
pom.xml里面加点东西

         <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>

One

今天搞一下el和jstl表达式

maven项目

index.jsp

DataServlet

Area类

target.jsp

结果

补充一下