IDEA创建servlet+jstl+jdbc

右键Add Framework Support





pom.xml加入依赖包

<dependencies>
<!--servlet-api-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
<!--JSP标准标签库-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!--mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.6</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<!--json-->
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20171018</version>
</dependency>
</dependencies>

创建ListServlet.java

package com.servlet;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;

@WebServlet("/baidu")
public class ListServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException{
super.doGet(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException{
this.doPost(request,response);
}

}

运行，浏览器输入http://localhost:8080/baidu

自动会跳到www.baidu.com

上面是使用注解方式处理的，下面使用非注解方式

web目录下新增WEB-INF目录，WEB-INF目录新增web.xml文件



web.xml内容

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
<servlet>
<servlet-name>listServlet</servlet-name>
<servlet-class>com.servlet.ListServlet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>listServlet</servlet-name>
<url-pattern>/baidu</url-pattern>
</servlet-mapping>
</web-app>

使用jdbc

创建user表

CREATE TABLE `mybatis`.`user`  (
`id` int(10) NOT NULL AUTO_INCREMENT,
`name` varchar(40) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT '',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

insert into `user`(name)values("aa"),("bb"),("cc");

创建User.java

package com.model;

public class User {
private int ID;
private String Name;

public int getID(){
return ID;
}

public String getName() {
return Name;
}

public void setID(int ID) {
this.ID = ID;
}

public void setName(String name) {
Name = name;
}
}

ListServlet.java修改

package com.servlet;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.model.User;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.json.JSONObject;

//@WebServlet("/baidu")
public class ListServlet extends HttpServlet{
private static final Log logger =
LogFactory.getLog(ListServlet.class);
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException{
//super.doGet(request,response);
//response.sendRedirect("http://www.baidu.com");

String url = "jdbc:mysql://192.168.1.229:3306/mybatis?characterEncoding=utf8&useSSL=true";
String username = "root";
String pass = "jsyx2016!";
Connection conn = null;
try{
//加载驱动
Class.forName("com.mysql.jdbc.Driver");
// 建立连接
conn = DriverManager.getConnection(url,username,pass);
String sql = "SELECT id,name FROM user";
PreparedStatement statement = conn.prepareStatement(sql);
ResultSet rs = statement.executeQuery();
List<User> userList = new ArrayList<User>();
while(rs.next()){
User user = new User();
user.setID(rs.getInt("id"));
user.setName(rs.getString("name"));
userList.add(user);
}
//logger.info(userList);
JSONObject json = new JSONObject();
json.put("list",userList);
System.out.println(json);

request.setAttribute("list",userList);

}catch (ClassNotFoundException e){
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}
//关闭连接
finally{
if(conn!=null){
try{
conn.close();
}catch(SQLException e){
e.printStackTrace();
}
}
}
String jsp = "/WEB-INF/jsp/index.jsp";
request.getRequestDispatcher(jsp).forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException{
//this.doPost(request,response);
}

}

WEB-INF目录创建jsp目录，jsp目录新增index.jsp，内容如下

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>列表</title>
</head>
<body>
<table>
<tr>
<th>序号</th>
<th>ID</th>
<th>Name</th>
</tr>
<c:forEach items="${list}" var="user" varStatus="status">
<tr>
<td>${status.index + 1}</td>
<td>${user.ID}</td>
<td>${user.name}</td>
</tr>
</c:forEach>
</table>
</body>
</html>

其中的

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

是引入jstl的申明部分