java servlet练习测试

步骤：

0、首先创建web project，工程名：test_servlet

1、编写Servlet，TestServlet.java文件内容：

package com.ouyang.servlet;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 javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@SuppressWarnings("serial")
public class TestServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {req.setCharacterEncoding("utf-8");String url = "jdbc:mysql://localhost:3306/test01";String user = "root";String password = "xxx";Connection connection = null;PreparedStatement preparedStatement = null;ResultSet resultSet = null;String sql = "select id, name, age from individual_information";List<List<String>> record = new ArrayList<>();try {Class.forName("com.mysql.jdbc.Driver");connection = DriverManager.getConnection(url, user, password);preparedStatement = connection.prepareStatement(sql);resultSet = preparedStatement.executeQuery();List<String> tmp = new ArrayList<>();while (resultSet.next()) {tmp.add(resultSet.getString("id"));tmp.add(resultSet.getString("name"));tmp.add(resultSet.getString("age"));record.add(new ArrayList<String>(tmp));tmp.clear();}} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}req.setAttribute("individual_information", record);RequestDispatcher requestDispatcher = req.getRequestDispatcher("get_info.jsp");requestDispatcher.forward(req, resp);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {this.doGet(req, resp);}
}

2、将servlet添加到web.xml，添加后的文件内容

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"><display-name>test_web</display-name><welcome-file-list><welcome-file>index.jsp</welcome-file></welcome-file-list><servlet><servlet-name>testServlet</servlet-name><servlet-class>com.ouyang.servlet.TestServlet</servlet-class></servlet><servlet-mapping><servlet-name>testServlet</servlet-name><url-pattern>/testServlet</url-pattern></servlet-mapping>  </web-app>

3、编写跳转页面 get_info.jsp

<%@page import="java.util.List"%>
<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%>
<!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>get_info</title>
</head>
<body><%@SuppressWarnings("unchecked")List<List<String>> record = (List<List<String>>)request.getAttribute("individual_information");for(List<String> list : record){out.println("<li>" + list.toString() + "</li>");}%>
</body>
</html>

【测试】

访问：http://localhost/test_servlet/testServlet