精通 Spring Boot 系列文(11)

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Spring Boot 整合 MyBatis

MyBatis 是目前优秀的 ORM 框架，支持普通的数据库操作，几乎消除了常规的 JDBC 操作，极大简化我们的开发操作。

1）编辑 pom.xml 文件

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>

    <groupId>com.nxgroupId>
    <artifactId>springbootdataartifactId>
    <version>1.0-SNAPSHOTversion>

    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.2.6.RELEASEversion>
        <relativePath/>
    parent>

    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
        <java.version>1.8java.version>
    properties>

    <dependencies>
        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-thymeleafartifactId>
        dependency>

        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>

        
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>1.3.1version>
        dependency>

        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <scope>testscope>
        dependency>
    dependencies>
project>

2）编辑 application.properties 文件

####################
### 数据源信息配置 ###
####################
# 数据库地址
spring.datasource.url=jdbc:mysql://localhost:3306/springbootdata?characterEncoding=utf8&useSSL=false&serverTimezone=UTC&rewriteBatchedStatements=true
# 用户名
spring.datasource.username=root
# 密码
spring.datasource.password=1234
# 数据库驱动
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
# 指定连接池中最大的活跃连接数.
spring.datasource.max-active=20
# 指定连接池最大的空闲连接数量.
spring.datasource.max-idle=8
# 指定必须保持连接的最小值
spring.datasource.min-idle=8
# 指定启动连接池时，初始建立的连接数量
spring.datasource.initial-size=10

3）创建 User 持久化类

public class User implements Serializable{

    private static final long serialVersionUID = 1L;

    private int id ;
    private String loginName ;
    private String username ;
    private String password;

    // setXxx 和 getXxx 方法
}

4）创建 UserRepository 数据访问接口

public interface UserRepository {

    @Insert("insert into tb_user(login_name ,username ,password) "
                + "values (#{loginName},#{username},#{password})")
    public int insertUser(User user);

    // 插入数据获取主键
    @Insert("insert into tb_user(login_name ,username ,password) "
            + "values (#{loginName},#{username},#{password})")
    @Options(useGeneratedKeys=true,keyProperty="id",keyColumn="id")
    public void insertGetKey(User user);


    @Select("select * from tb_user where username = #{username}")
    // 引用id="userResult"的@Results
    @ResultMap("userResult")
    public User selectByUsername(@Param("username")String username);

    @Select("select * from tb_user")
    // @Results用于映射对象属性和数据库列，常用于对象属性和数据库列不同名情况
    @Results(id="userResult",value={
            @Result(id=true,column="id",property="id"),
            @Result(column="login_name",property="loginName"),
            @Result(column="password",property="password"),
            @Result(column="username",property="username")
        })
    public List findAll();


    @Delete("delete from tb_user where id=#{id}")
    public void delete(final Integer id);


    @Select("select * from tb_user where id=#{id}")
    // 引用id="userResult"的@Results
    @ResultMap("userResult")
    public User findUserById(int id);

    @Update("update tb_user set username=#{username}, login_name=#{loginName} where id=#{id}")
    public void update(final User user);
}

5）创建 UserService 业务层类

@Service
public class UserService {

    // 注入UserRepository
    @Resource
    private UserRepository userRepository;

    public int insertUser(User user){
        return userRepository.insertUser(user);
    }

    public User selectByUsername(String username){
        return userRepository.selectByUsername(username);
    }

    public List findAll(){
        return userRepository.findAll();
    }

    public void insertGetKey(User user) {
        userRepository.insertGetKey(user);
    }

    public void update(User user) {
        userRepository.update(user);
    }

    public void delete(Integer id) {
        userRepository.delete(id);
    }
}

6）创建 UserController 控制器类

@RestController
@RequestMapping("/user")
public class UserController {

    // 注入UserService
    @Resource
    private UserService userService;

    @RequestMapping("/insertUser")
    public String insertUser(User user){
        return "插入数据["+userService.insertUser(user)+"]条";
    }

    @RequestMapping("/insertGetKey")
    public User insertGetKey(User user) {
        userService.insertGetKey(user);
        return user ;
    }

    @RequestMapping("/selectByUsername")
    public User selectByUsername(String username){
        return userService.selectByUsername(username);
    }

    @RequestMapping("/findAll")
    public List findAll(){
        return userService.findAll();
    }

    @RequestMapping("/update")
    public void update(User user) {
        userService.update(user);
    }

    @RequestMapping("/delete")
    public void delete(Integer id) {
        userService.delete(id);
    }
}

7）测试

http://localhost:8080/user/insertUser?loginName=shuaishuai&username=小猿&password=123123

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