1、整合JDBC

1.1、搭建项目环境

1.1.1、创建表
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CREATE TABLE `test`.`user` (
  `userid` INT NOT NULL AUTO_INCREMENT,
  `username` VARCHAR(30) NULL,
  `usersex` VARCHAR(10) NULL,
  PRIMARY KEY (`userid`));
1.1.2、创建项目

在这里插入图片描述

1.1.3、修改POM文件
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.xiezhenyu</groupId>
    <artifactId>springbootjdbc</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springbootjdbc</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Thymeleaf启动器坐标 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!-- jdbc启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!-- mysql数据库驱动坐标 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.18</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

1.2、配置数据源

1.2.1、通过自定义配置文件方式配置数据源信息
1.2.1.1、通过@PropertySource注解读取配置信息

  • 添加Druid数据源依赖

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    <!-- Druid数据源依赖 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.12</version>
    </dependency>

  • 创建Properties文件

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    jdbc.driverClassName=com.mysql.cj.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/test?userUnicode=true&characterEncoding=UTF-8&userSSL=false&serverTimezone=Asia/Shanghai
    jdbc.username=root
    jdbc.password=p123456

  • 创建配置类

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    package com.xiezhenyu.springbootjdbc.config;
    import com.alibaba.druid.pool.DruidDataSource;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    import javax.sql.DataSource;
    /**
     * 数据源jdbc的配置类
     */
    @Configuration
    @PropertySource("classpath:/jdbc.properties")//加载指定的properties配置文件
    public class JdbcConfiguration {
        @Value("${jdbc.driverClassName}")
        private String driverClassName;
        @Value("${jdbc.url}")
        private String url;
        @Value("${jdbc.username}")
        private String username;
        @Value("${jdbc.password}")
        private String password;
        /**
         * 实例化Druid
         */
        @Bean
        public DataSource getDatasource(){
            DruidDataSource source = new DruidDataSource();
            source.setUsername(this.username);
            source.setPassword(this.password);
            source.setUrl(this.url);
            source.setDriverClassName(this.driverClassName);
            return source;
        }
    }
1.2.1.2、通过@ConfigurationProperties注解读取配置信息

  • 创建配置信息实体类

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    /**
     * JDBC配置信息属性类
     */
    @ConfigurationProperties(prefix = "jdbc") //是SpringBoot的注解，不能读取其他的配置文件，只能读取SpringBoot的application配置文件
    public class JdbcProperties {
        private String driverClassName;
        private String url;
        private String username;
        private String password;
        public String getDriverClassName() {
            return driverClassName;
        }
        public void setDriverClassName(String driverClassName) {
            this.driverClassName = driverClassName;
        }
        public String getUrl() {
            return url;
        }
        public void setUrl(String url) {
            this.url = url;
        }
        public String getUsername() {
            return username;
        }
        public void setUsername(String username) {
            this.username = username;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
    }

  • 修改配置类

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    /**
     * 数据源jdbc的配置类
     */
    @Configuration
    @EnableConfigurationProperties(JdbcProperties.class)//指定加载哪个配置信息属性类
    public class JdbcConfiguration {
        @Autowired
        private JdbcProperties jdbcProperties;
        /**
         * 实例化Druid
         */
        @Bean
        public DataSource getDatasource(){
            DruidDataSource source = new DruidDataSource();
            source.setUsername(this.jdbcProperties.getUsername());
            source.setPassword(this.jdbcProperties.getPassword());
            source.setUrl(this.jdbcProperties.getUrl());
            source.setDriverClassName(this.jdbcProperties.getDriverClassName());
            return source;
        }
    }
1.2.1.3、@ConfigurationProperties注解的优雅使用方式

  在上面使用@ConfigurationProperties的时候，需要通过@ConfigurationProperties配置信息的实体类，进而在数据源配置类中通过注入的方式读取配置信息实体类，来获取信息。
  其实@ConfigurationProperties还可以在方法中使用当实例化Druid的时候可以直接在方法上添加@ConfigurationProperties注解，来获取配置信息。而这个注解就会自动把配置信息中的uername、password等数据自动调用DruidDataSource 的setUsername、setPassword等方法来设置信息。

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/**
 * 数据源jdbc的配置类
 */
@Configuration
public class JdbcConfiguration {
    /**
     * 实例化Druid
     */
    @Bean
    @ConfigurationProperties(prefix = "jdbc")
    public DataSource getDatasource(){
        DruidDataSource source = new DruidDataSource();
        return source;
    }
}
1.2.2、通过Spring Boot配置文件配置数据源信息

  在Spring Boot1.x版本中的spring-boot-starter-jdbc启动器中默认使用的是org.apache.tomcat.jdbc.pool.DataSource作为数据源。
  在Spring Boot2.x版本中的spring-boot-starter-jdbc启动器默认使用的是com.zaxxer.hikariDataSource作为数据源。

1.2.2.1、使用Spring Boot默认的HikariDataSource数据源

  在application.properties中配置以下信息之后，在需要到数据源的时候直接注入即可。

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spring.datasource.url=jdbc:mysql://localhost:3306/test?userUnicode=true&characterEncoding=UTF-8&userSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=p123456

测试代码

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@Controller
public class UsersController {
    @Autowired
    private DataSource dataSource;
    @GetMapping("/showInfo")
    public String showInfo(){
        return "OK";
    }
}
1.2.2.2、使用第三方的Druid数据源

  在application.properties配置文件中配置spring.datasource.type就可以更换数据源了。

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spring.datasource.url=jdbc:mysql://localhost:3306/test?userUnicode=true&characterEncoding=UTF-8&userSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=p123456
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

1.3、实现添加用户功能

1.3.1、创建POJO
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public class Users {
    private Integer userid;
    private String username;
    private String usersex;
    public Integer getUserid() {
        return userid;
    }
    public void setUserid(Integer userid) {
        this.userid = userid;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getUsersex() {
        return usersex;
    }
    public void setUsersex(String usersex) {
        this.usersex = usersex;
    }
}
1.3.2、创建页面
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Title</title>
</head>
<body>
    <from th:action="@{/user/addUser}" method="post">
        <input type="text" name="username"/><br/>
        <input type="text" name="usersex"/><br/>
        <input type="submit" value="ok"/>
    </from>
</body>
</html>
1.3.3、创建Controller

  • PageController

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    /**
     * 页面跳转Controller
     */
    @Controller
    public class PageController {
        //页面跳转方法
        @RequestMapping("/{page}")
        public String showPage(@PathVariable String page){
            return page;
        }
    }

  • UserController

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    @Controller
    @RequestMapping("/user")
    public class UsersController {
        @Autowired
        private UsersService usersService;
        @GetMapping("/showInfo")
        public String showInfo(){
            return "OK";
        }
        //添加用户
        @PostMapping("/addUser")
        public String addUser(Users users){
            try{
                this.usersService.addUser(users);
            }catch (Exception e){
                e.printStackTrace();
                return "error";
            }
            return "redirect:/ok";
        }
    }
1.3.4、创建Service
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/**
 * 用户管理业务层
 */
@Service
public class UserServiceImpl implements UsersService {
    @Autowired
    private UserDao userDao;

    /**
     * 添加用户
     * @param users
     */
    @Override
    @Transactional
    public void addUser(Users users) {
        this.userDao.insertUsers(users);
    }
}
1.3.5、创建Dao
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/**
 * 用户管理持久层
 */
@Repository
public class UserDaoImpl implements UserDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    /**
     * 添加用户
     * @param users
     */
    @Override
    public void insertUsers(Users users) {
        String sql = "insert into user(username,usersex) values(?,?)";
        this.jdbcTemplate.update(sql,users.getUsername(),users.getUsersex());
    }
}
1.3.4、解决favicon.ico解析问题
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<link rel="shortcut icon" href="../resource/favicon.ico" th:href="@{/static/favicon.ico}"/>

1.4、实现查询全部用户功能

1.4.1、修改Controller
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//查询用户
@GetMapping("/showUser")
public String showUser(Model model){
    List<Users> list = new ArrayList<>();
    try{
        list = this.usersService.showUsers();
    }catch (Exception e){
        e.printStackTrace();
        return "error";
    }
    model.addAttribute("list",list);
    return "showUser";
}
1.4.2、修改业务层
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/**
 * 查询用户
 * @return
 */
@Override
@Transactional
public List<Users> showUsers(){
    return this.userDao.showUsers();
}
1.4.3、修改持久层

使用RowMapper返回自定义对象。

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/**
 * 查询用户
 * @return
 */
@Override
public List<Users> showUsers(){
    String sql = "select * from user";
    List<Users> users = this.jdbcTemplate.query(sql, new RowMapper<Users>() {
        @Override
        public Users mapRow(ResultSet resultSet, int i) throws SQLException {
            Users user = new Users();
            user.setUsername(resultSet.getString("username"));
            user.setUsersex(resultSet.getString("usersex"));
            user.setUserid(resultSet.getInt("userid"));
            return user;
        }
    });
    return users;
}
1.4.4、创建用户更新页面
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Title</title>
</head>
<body>
    <table border="1" width="50%" align="center">
        <tr>
            <th>ID</th>
            <th>用户名</th>
            <th>性别</th>
            <th>操作</th>
        </tr>
        <tr th:each="u : ${list}">
            <td th:text="${u.userid}"></td>
            <td th:text="${u.username}"></td>
            <td th:text="${u.usersex}"></td>
            <td>
                <a th:href="@{/user/updateUser}">修改</a>
                <a th:href="@{/user/deleteUser}">删除</a>
            </td>
        </tr>
    </table>
</body>
</html>

1.5、实现用户更新功能

1.5.1、预更新查询
1.5.1.1、修改Controller
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//预更新用户的查询
@GetMapping("/preUpdateUser")
public  String preUpdateUser(Integer id,Model model){
    try{
        Users user = this.usersService.findUserById(id);
        model.addAttribute("user",user);
    }catch (Exception e){
        e.printStackTrace();
        return "error";
    }
    return "updateUser";
}
1.5.1.2、修改业务层
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/**
 * 用户预更新查询
 */
@Override
@Transactional
public Users findUserById(int id){
    return this.userDao.selectUserById(id);
}
1.5.1.3、修改持久层
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/**
 * 预更新用户查询
 */
public Users selectUserById(int id){
    Users user = new Users();
    String sql = "select * from user where userid = ?";
    Object[] arr = new Object[]{id};
    this.jdbcTemplate.query(sql, arr,new RowCallbackHandler() {
        @Override
        public void processRow(ResultSet resultSet) throws SQLException {
            user.setUserid(resultSet.getInt("userid"));
            user.setUsersex(resultSet.getString("usersex"));
            user.setUsername(resultSet.getString("username"));
        }
    });
    return user;
}
1.5.1.4、创建用户更新页面
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Title</title>
</head>
<body>
<form th:action="@{/user/updateUser}" method="post">
    <input type="hidden" name="userid" th:value="${user.userid}"/>
    <input type="text" name="username" th:value="${user.username}"/><br/>
    <input type="text" name="usersex" th:value="${user.usersex}"/><br/>
    <input type="submit" value="修改"/>
</form>
</body>
</html>
1.5.2、更新用户
1.5.2.1、修改Controller
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//更新用户
@PostMapping("/updateUser")
public String updateUser(Users user){
    try{
        this.usersService.modifyUser(user);
    }catch (Exception e){
        e.printStackTrace();
        return "error";
    }
    return "ok";
}
1.5.2.2、修改业务层
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/**
 * 用户更新
 * @param user
 */
@Override
@Transactional
public void modifyUser(Users user){
    this.userDao.updateUser(user);
}
1.5.2.3、修改持久层
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/**
 * 更新用户
 */
public void updateUser(Users user){
    String sql = "update user set username = ?,usersex = ? where userid = ?";
    jdbcTemplate.update(sql,user.getUsername(),user.getUsersex(),user.getUserid());
}
1.5.3、删除用户
1.5.3.1、修改Controller
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//删除用户
@GetMapping("/deleteUser")
public String deleteUser(Integer id){
    try{
        this.usersService.dropUser(id);
    }catch (Exception e){
        e.printStackTrace();
        return "error";
    }
    return "redirect:/ok";
}
1.5.3.2、修改业务层
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/**
 * 删除用户
 */
@Override
public void dropUser(Integer id){
    this.userDao.deleteUser(id);
}
1.5.3.3、修改持久层
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/**
 * 删除用户
 */
public void deleteUser(Integer id){
    String sql = "delete from user where userid = ?";
    jdbcTemplate.update(sql,id);
}