image.png

demo1.0

思路

image.png

  1. 完成一个用户信息查询功能
  2. 1、数据库创建USER表
  3.     int id;
  4.     String name;
  5.     String gender;
  6.     int age;
  7.     String address;
  8.     String qq;
  9.     String email;
  11. 2、思路：
  12.     用户通过index.jsp点击查询所有用户信息，在list.jsp上面显示
  13.     index.jsp往servlet里面查询，servlet调用服务层的方法进行查询，然后返回信息到list.jsp
  14.     服务层：存在一个接口UserService和实现类UserServiceImpl,服务层调用dao层的方法进行发现用户数据
  15.     dao层：存在一个接口UserDao和实现类UserDaoImpl，dao层使用JDBC操作数据库，调用了util工具类中的jdbcutils类

配置文件

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0"
  3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  5.     <modelVersion>4.0.0</modelVersion>
  7.     <groupId>com.example</groupId>
  8.     <artifactId>zhongdiandemo1</artifactId>
  9.     <version>1.0-SNAPSHOT</version>
  10.     <name>zhongdiandemo1</name>
  11.     <packaging>war</packaging>
  13.     <properties>
  14.         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  15.         <maven.compiler.target>1.8</maven.compiler.target>
  16.         <maven.compiler.source>1.8</maven.compiler.source>
  17.         <junit.version>5.7.1</junit.version>
  18.     </properties>
  20.     <dependencies>
  21.         <dependency>
  22.             <groupId>javax.servlet</groupId>
  23.             <artifactId>javax.servlet-api</artifactId>
  24.             <version>4.0.1</version>
  25.             <scope>provided</scope>
  26.         </dependency>
  27.         <dependency>
  28.             <groupId>org.junit.jupiter</groupId>
  29.             <artifactId>junit-jupiter-api</artifactId>
  30.             <version>${junit.version}</version>
  31.             <scope>test</scope>
  32.         </dependency>
  33.         <dependency>
  34.             <groupId>org.junit.jupiter</groupId>
  35.             <artifactId>junit-jupiter-engine</artifactId>
  36.             <version>${junit.version}</version>
  37.             <scope>test</scope>
  38.         </dependency>
  42.         <dependency>
  43.             <groupId>com.alibaba</groupId>
  44.             <artifactId>druid</artifactId>
  45.             <version>1.2.6</version>
  46.         </dependency>
  48.         <dependency>
  49.             <groupId>mysql</groupId>
  50.             <artifactId>mysql-connector-java</artifactId>
  51.             <version>8.0.22</version>
  52.         </dependency>
  54.         <dependency>
  55.             <groupId>org.springframework</groupId>
  56.             <artifactId>spring-jdbc</artifactId>
  57.             <version>5.3.9</version>
  58.         </dependency>
  60.         <dependency>
  61.             <groupId>commons-beanutils</groupId>
  62.             <artifactId>commons-beanutils</artifactId>
  63.             <version>1.9.4</version>
  64.         </dependency>
  66.         <dependency>
  67.             <groupId>javax.servlet</groupId>
  68.             <artifactId>servlet-api</artifactId>
  69.             <version>2.5</version>
  70.             <scope>provided</scope>
  71.         </dependency>
  72.         <dependency>
  73.             <groupId>javax.servlet</groupId>
  74.             <artifactId>jsp-api</artifactId>
  75.             <version>2.0</version>
  76.             <scope>provided</scope>
  77.         </dependency>
  79.         <dependency>
  80.             <groupId>jstl</groupId>
  81.             <artifactId>jstl</artifactId>
  82.             <version>1.2</version>
  83.         </dependency>
  84.         <dependency>
  85.             <groupId>taglibs</groupId>
  86.             <artifactId>standard</artifactId>
  87.             <version>1.1.2</version>
  88.         </dependency>
  91.     </dependencies>
  93.     <build>
  94.         <plugins>
  95.             <plugin>
  96.                 <groupId>org.apache.maven.plugins</groupId>
  97.                 <artifactId>maven-war-plugin</artifactId>
  98.                 <version>3.3.1</version>
  99.             </plugin>
  100.         </plugins>
  101.     </build>
  102. </project>
  1. url=jdbc:mysql://ip:3306/lww?useUnicode=true&characterEncoding=utf8
  2. username=root
  3. password=xxxxxxx
  4. driver=com.mysql.cj.jdbc.Driver

jsp

  1. <%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
  2. <!doctype html>
  3. <html lang="zh-CN">
  4. <head>
  5.     <meta charset="utf-8">
  6.     <meta http-equiv="X-UA-Compatible" content="IE=edge">
  7.     <meta name="viewport" content="width=device-width, initial-scale=1">
  8.     <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
  9.     <title>Bootstrap helloworld</title>
  11.     <!-- Bootstrap
  12.     在zd项目中，如果不加上虚拟目录zd,查看网页会发现，引用的是http://localhost:8080/css/bootstrap.min.css
  13.     是没有办法访问到的，因为项目在tomcat中部署，在Tomcat的zd项目里面
  14.     -->
  15.     <link rel="stylesheet" href="/zd/css/bootstrap.min.css" integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
  18. </head>
  19. <body>
  20. <div align="center">
  21.     <a href="${pageContext.request.contextPath}/userListServlet" style="...">
  22.         查询所有用户信息
  23.     </a>
  24. </div>
  26. <!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
  27. <!--<script src="/js/jquery-3.6.0.min.js" integrity="sha384-nvAa0+6Qg9clwYCGGPpDQLVpLNn0fRaROjHqs13t4Ggj3Ez50XnGQqc/r8MhnRDZ" crossorigin="anonymous"></script>-->
  28. <script src="/zd/js/jquery-3.6.0.min.js" crossorigin="anonymous"></script>
  29. <!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
  30. <script src="/zd/js/bootstrap.min.js" integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd" crossorigin="anonymous"></script>
  31. </body>
  32. </html>
  1. <%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
  3. <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
  6. <!doctype html>
  7. <html lang="zh-CN">
  8. <head>
  9.     <meta charset="utf-8">
  10.     <meta http-equiv="X-UA-Compatible" content="IE=edge">
  11.     <meta name="viewport" content="width=device-width, initial-scale=1">
  12.     <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
  13.     <title>Bootstrap helloworld</title>
  15.     <!-- Bootstrap
  16.     在zd项目中，如果不加上虚拟目录zd,查看网页会发现，引用的是http://localhost:8080/css/bootstrap.min.css
  17.     是没有办法访问到的，因为项目在tomcat中部署，在Tomcat的zd项目里面
  18.     -->
  19.     <link rel="stylesheet" href="/zd/css/bootstrap.min.css" integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
  21.     <style type="text/css">
  22.         h3,td,th{
  23.             text-align: center;
  24.         }
  26.     </style>
  28. </head>
  29. <body>
  30. <div class="container">
  31.     <h3 style="...">用户信息列表</h3>
  32.     <table border="1" class="table table-bordered table-hover">
  33.         <tr class="success">
  34.             <th>编号</th>
  35.             <th>姓名</th>
  36.             <th>性别</th>
  37.             <th>年龄</th>
  38.             <th>籍贯</th>
  39.             <th>QQ</th>
  40.             <th>邮箱</th>
  41.             <th>操作</th>
  42.         </tr>
  44.         <c:forEach items="${users}" var="user" varStatus="s">
  45.             <tr>
  46.                 <td>${s.count}</td>
  47.                 <td>${user.name}</td>
  48.                 <td>${user.gender}</td>
  49.                 <td>${user.age}</td>
  50.                 <td>${user.address}</td>
  51.                 <td>${user.qq}</td>
  52.                 <td>${user.email}</td>
  53.                 <td><a class="btn btn-default btn-sm" href="update.html">修改</a>&nbsp;<a class="btn btn-default btn-sm" href="">删除</a></td>
  54.             </tr>
  56.         </c:forEach>
  59.         <tr>
  60.             <td colspan="8" align="center"><a class="btn btn-default" href="add.html">添加联系人</a></td>
  61.         </tr>
  62.     </table>
  63. </div>
  65. <!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
  66. <!--<script src="/js/jquery-3.6.0.min.js" integrity="sha384-nvAa0+6Qg9clwYCGGPpDQLVpLNn0fRaROjHqs13t4Ggj3Ez50XnGQqc/r8MhnRDZ" crossorigin="anonymous"></script>-->
  67. <script src="/zd/js/jquery-3.6.0.min.js" crossorigin="anonymous"></script>
  68. <!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
  69. <script src="/zd/js/bootstrap.min.js" integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd" crossorigin="anonymous"></script>
  70. </body>
  71. </html>

servlet

  1. package com.example.zhongdiandemo1.web.servlet;
  3. import com.example.zhongdiandemo1.domain.User;
  4. import com.example.zhongdiandemo1.service.UserService;
  5. import com.example.zhongdiandemo1.service.impl.UserServiceImpl;
  7. import javax.servlet.*;
  8. import javax.servlet.http.*;
  9. import javax.servlet.annotation.*;
  10. import java.io.IOException;
  11. import java.util.List;
  13. @WebServlet("/userListServlet")
  14. public class UserListServlet extends HttpServlet {
  15.     @Override
  16.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  17.         //调用UserService完成查询
  18.         UserService service = new UserServiceImpl();
  19.         List<User> users = service.findAll();
  20.         //将list存入request域
  21.         request.setAttribute("users",users);
  22.         //转发到list.jsp
  23.         request.getRequestDispatcher("list.jsp").forward(request,response);
  26.     }
  28.     @Override
  29.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  30.         this.doGet(request, response);
  31.     }
  32. }

util

  1. package com.example.zhongdiandemo1.util;
  3. import com.alibaba.druid.pool.DruidDataSourceFactory;
  5. import javax.sql.DataSource;
  6. import java.io.IOException;
  7. import java.io.InputStream;
  8. import java.sql.Connection;
  9. import java.sql.SQLException;
  10. import java.util.Properties;
  12. public class jdbcutils {
  13.     private static DataSource ds;
  15.     static {
  16.         try {
  17.             //加载配置文件
  18.             Properties pro = new Properties();
  19.             InputStream is = jdbcutils.class.getClassLoader().getResourceAsStream("druid.properties");
  20.             pro.load(is);
  22.             //初始化连接池对象
  23.             ds = DruidDataSourceFactory.createDataSource(pro);
  26.         } catch (IOException e) {
  27.             e.printStackTrace();
  28.         } catch (Exception e) {
  29.             e.printStackTrace();
  30.         }
  32.     }
  34.     /**
  35.      * 获取连接池对象
  36.      */
  37.     public static DataSource getDataSource(){
  38.         return ds;
  39.     }
  41.     /**
  42.      * 获取Connection对象
  43.      */
  44.     public static Connection getConnection() throws SQLException {
  45.         return ds.getConnection();
  46.     }
  50. }

服务层

  1. package com.example.zhongdiandemo1.service;
  3. import com.example.zhongdiandemo1.domain.User;
  5. import java.util.List;
  7. /**
  8.  * 用户管理的业务接口
  9.  */
  10. public interface UserService {
  11.     /**
  12.      * 查询所有用户信息
  13.      * @return
  14.      */
  15.     public List<User> findAll();
  16. }
  1. package com.example.zhongdiandemo1.service.impl;
  3. import com.example.zhongdiandemo1.dao.UserDao;
  4. import com.example.zhongdiandemo1.dao.impl.UserDaoImpl;
  5. import com.example.zhongdiandemo1.domain.User;
  6. import com.example.zhongdiandemo1.service.UserService;
  8. import java.util.List;
  10. public class UserServiceImpl implements UserService {
  11.     //实例化一个dao的使用对象，使用多态的形式
  12.     private UserDao dao = new UserDaoImpl();
  14.     @Override
  15.     public List<User> findAll() {
  16.         //调用Dao完成查询
  17.         return dao.findAll();
  18.     }
  19. }

domain-javabean存放get/set方法的类

  1. package com.example.zhongdiandemo1.domain;
  3. public class User {
  4.     private int id;
  5.     private String name;
  6.     private String gender;
  7.     private int age;
  8.     private String address;
  9.     private String qq;
  10.     private String email;
  12.     public int getId() {
  13.         return id;
  14.     }
  16.     public void setId(int id) {
  17.         this.id = id;
  18.     }
  20.     public String getName() {
  21.         return name;
  22.     }
  24.     public void setName(String name) {
  25.         this.name = name;
  26.     }
  28.     public String getGender() {
  29.         return gender;
  30.     }
  32.     public void setGender(String gender) {
  33.         this.gender = gender;
  34.     }
  36.     public int getAge() {
  37.         return age;
  38.     }
  40.     public void setAge(int age) {
  41.         this.age = age;
  42.     }
  44.     public String getAddress() {
  45.         return address;
  46.     }
  48.     public void setAddress(String address) {
  49.         this.address = address;
  50.     }
  52.     public String getQq() {
  53.         return qq;
  54.     }
  56.     public void setQq(String qq) {
  57.         this.qq = qq;
  58.     }
  60.     public String getEmail() {
  61.         return email;
  62.     }
  64.     public void setEmail(String email) {
  65.         this.email = email;
  66.     }
  68.     @Override
  69.     public String toString() {
  70.         return "User{" +
  71.                 "id=" + id +
  72.                 ", name='" + name + '\'' +
  73.                 ", gender='" + gender + '\'' +
  74.                 ", age=" + age +
  75.                 ", address='" + address + '\'' +
  76.                 ", qq='" + qq + '\'' +
  77.                 ", email='" + email + '\'' +
  78.                 '}';
  79.     }
  80. }

dao层

  1. package com.example.zhongdiandemo1.dao;
  3. import com.example.zhongdiandemo1.domain.User;
  5. import java.util.List;
  7. /**
  8.  * 用户操作的Dao
  9.  */
  10. public interface UserDao {
  11.     public List<User> findAll();
  12. }
  1. package com.example.zhongdiandemo1.dao.impl;
  3. import com.example.zhongdiandemo1.dao.UserDao;
  4. import com.example.zhongdiandemo1.domain.User;
  5. import com.example.zhongdiandemo1.util.jdbcutils;
  6. import org.springframework.jdbc.core.BeanPropertyRowMapper;
  7. import org.springframework.jdbc.core.JdbcTemplate;
  9. import java.util.List;
  11. public class UserDaoImpl implements UserDao {
  12.     private JdbcTemplate template = new JdbcTemplate(jdbcutils.getDataSource());
  14.     @Override
  15.     public List<User> findAll() {
  16.         //使用JDBC操作数据库
  17.         String sql = "select * from USER";
  18.         //使用BeanPropertyRowMapper时，是给query()方法传递一个BeanPropertyRowMapper对象，
  19.         // 让JdbcTemplate帮我们把查询结果集users的每一行结果都使用BeanPropertyRowMapper.mapRow()方法，转化成我们想要的Java类对象
  20.         List<User> users = template.query(sql, new BeanPropertyRowMapper<User>(User.class));
  21.         return users;
  22.     }
  23. }