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Spring Boot学习笔记(十二) -整合持久层技术(MyBatis篇)

2020-04-14 20:36 388人阅读  评论(0)

  通过使用Spring Boot+Spring MVC + Mybatis 整合实现一个对数据库中的users表的CRUD的操作。

1、创建项目

1.1、修改POM文件

<?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>springbootmybatis2</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springbootmybatis2</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!-- thymeleaf 启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!-- springboot web启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- mybatis 启动器 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.2</version>
        </dependency>
        <!-- Druid数据源依赖 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.12</version>
        </dependency>
        <!-- mysql数据库驱动坐标 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.18</version>
        </dependency>
        <!-- 测试启动器 -->
        <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>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>
</project>

1.2、添加application.properties全部配置文件

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?userUnicode=true&characterEncoding=UTF-8&userSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=p123456
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
mybatis.type-aliases-package=com.xiezhenyu.springbootmybatis2.pojo

1.3、数据库表设计

2、添加用户

2.1、创建实体类

package com.xiezhenyu.springbootmybatis2.pojo;

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;
    }
}

2.2、创建mapper接口以及映射配置文件

mapper接口

public interface UsersMapper {
    void insertUser(Users users);
}

映射配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xiezhenyu.springbootmybatis2.mapper.UsersMapper">
    <insert id="inserUser" parameterType="users">
        insert into users(username,usersex) values(#{username},#{usersex})
    </insert>
</mapper>

2.3、创建业务层

public class UsersServiceImpl implements UsersService {
    @Autowired
    private UsersMapper usersMapper;

    @Override
    public void addUser(Users users) {
        this.usersMapper.insertUser(users);
    }
}

2.4、创建Controller

@Controller
@RequestMapping("/users")
public class UsersController {
    @Autowired
    private UsersService usersService;
    /**
     * 页面跳转
     */
    @RequestMapping("/{page}")
    public String showPage(@PathVariable String page){
        return page;
    }
    /**
     * 添加用户
     */
    @PostMapping("/addUser")
    public String addUser(Users users){
        this.addUser(users);
        return "ok";
    }
}

2.5、编写页面

<!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>
    <link rel="shortcut icon" href="../resource/favicon.ico" th:href="@{/static/favicon.ico}"/>
    <title>Title</title>
</head>
<body>
<form th:action="@{/users/addUser}" method="post">
    <input type="text" name="username"/><br/>
    <input type="text" name="usersex"/><br/>
    <input type="submit" value="ok"/>
</form>
</body>
</html>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>Title</title>
</head>
<body>
    <span>操作成功！</span>
</body>
</html>

2.6、启动类

@SpringBootApplication
@MapperScan("com.xiezhenyu.mapper") //@MapperScan 用于扫描Mybatis的mapper接口
public class Springbootmybatis2Application {
    public static void main(String[] args) {
        SpringApplication.run(Spirngbootmybatis2Application.class, args);
    }
}

3、查询用户

3.1、创建mapper及映射配置文件

public interface UsersMapper {
    void insertUser(Users users);
    List<Users> selectUsersAll();
}

<select id="selectUsersAll" resultType="users">
    select * from users
</select>

3.2、在业务层中添加查询方法

@Override
public List<Users> findUserAll() {
    return this.usersMapper.selectUsersAll();
}

3.3、在Controller中添加方法

/**
 * 查询用户
 */
@RequestMapping("/findUserAll")
public String findUser(Model model){
    List<Users> list = this.usersService.findUserAll();
    model.addAttribute("list",list);
    return "showUser";
}

3.4、编写页面

<!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/preUpdateUser(id=${u.userid})}">修改</a>
                <a th:href="@{/user/deleteUser(id=${u.userid})}">删除</a>
            </td>
        </tr>
    </table>
</body>
</html>

4、用户预更新

4.1、创建mapper及映射配置文件

public interface UsersMapper {
    void insertUser(Users users);
    List<Users> selectUsersAll();
    Users selectUserById(Integer id);
}

<select id="selectUserById" parameterType="Integer" resultType="users">
    select * from users where userid = #{userid}
</select>

4.2、在业务层中添加查询方法

@Override
public Users findUserById(Integer id) {
    return this.usersMapper.selectUserById(id);
}

4.3、在Controller中添加方法

/**
 * 预更新查询
 */
@RequestMapping("/preUpdateUser")
public String findUserById(Integer id,Model model){
    Users user = this.usersService.findUserById(id);
    model.addAttribute("user",user);
    return "updateUser";
}

4.4、编写页面

<!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>

5、用户修改

5.1、创建mapper及映射配置文件

public interface UsersMapper {
    void insertUser(Users users);
    List<Users> selectUsersAll();
    Users selectUserById(Integer id);
    void updateUser(Users users);
}

<update id="updateUser" parameterType="users">
    update users set username=#{username},usersex=#{usersex} where userid = #{userid}
</update>

5.2、在业务层中添加查询方法

@Override
public void updateUser(Users users) {
    this.usersMapper.updateUser(users);
}

5.3、在Controller中添加方法

/**
 * 用户更新
 */
@RequestMapping("updateUser")
public String updateUser(Users users){
    this.usersService.updateUser(users);
    return "ok";
}

6、用户删除

6.1、创建mapper及映射配置文件

public interface UsersMapper {
    void insertUser(Users users);
    List<Users> selectUsersAll();
    Users selectUserById(Integer id);
    void updateUser(Users users);
    void deleteUserById(Integer id);
}

<delete id="deleteUserById" parameterType="Integer">
    delete from users where userid = #{userid}
</delete>

6.2、在业务层中添加查询方法

@Override
public void deleteUserById(Integer id) {
    this.usersMapper.deleteUserById(id);
}

6.3、在Controller中添加方法

/**
 * 删除用户
 */
@RequestMapping("deleteUser")
public String deleteUserById(Integer id){
    this.usersService.deleteUserById(id);
    return "ok";
}

转载：https://blog.csdn.net/qq_39356904/article/details/105412496
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