10 springboot整合mybatis

所有mapper文件继承BaseMapper，不用写sql语句

目录结构：

1 添加依赖

pom.xml

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

    <groupId>org.example</groupId>
    <artifactId>springboot_learn</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <artifactId>spring-boot-starter-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.1.6.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.6</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <!--不传递依赖-->
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <!--jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.0</version>
        </dependency>
        <!--通用mapper-->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.1.5</version>
        </dependency>

    </dependencies>

</project>

2 创建数据库连接参数的配置文件

spring中配置datasource；注意使用默认的hikari

application.yml

# 激活配置文件；需要指定其他配置文件的名称
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test
    username: root
    password: root

# tomcat 端口设置
server:
  port: 80

3 不同层的文件

pojo层

HelloController

package li.chen.com.pojo;


import lombok.Data;
import tk.mybatis.mapper.annotation.KeySql;

import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.Table;
import java.util.Date;

/**
 * @Data 此注解自动生成get，set,toString等方法
 * @Table 此实体类对应的数据库表名
 * @KeySql(useGeneratedKeys = true) 数据库主键回填
 *@Column(name="user_name") 指定此属性映射的数据库字段名称；
 注意；若不加此注解，会自动将驼峰命名转换为下划线 userName --> user_name
 * @Verson 1.0
 **/
@Data
@Table(name = "user")  //对应的数据库表
public class User {
    @Id
    @KeySql(useGeneratedKeys = true)     //主键回填
    private Integer id;

    @Column(name="userName")
    private String userName;

    @Column(name="passWord")
    private String passWord;

    private Date birthday;
}

mapper层

package li.chen.com.mapper;

import li.chen.com.pojo.User;
import tk.mybatis.mapper.common.BaseMapper;

/**
 * @Mapper  或统一在 Application中配置 @MapperScan
 **/
//@Mapper 
public interface UserMapper extends BaseMapper<User> {
}

service层

package li.chen.com.service;

import li.chen.com.mapper.UserMapper;
import li.chen.com.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    //根据id查询
    public User queryById(Long id){
        return userMapper.selectByPrimaryKey(id);
    }

}

controller层

package li.chen.com.controller;

import li.chen.com.pojo.User;
import li.chen.com.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import javax.sql.DataSource;


@RestController
public class HelloController {
    @Autowired
    private DataSource dataSource;

    @Autowired
    private UserService userService;

    @GetMapping("/user/{id}")
    public User queryById(@PathVariable Long id){
        return userService.queryById(id);
    }

    @Transactional
    @GetMapping("hello")
    public String hello() {
        System.out.println("DataSource=" + dataSource);
        return "hello,spring boot";
    }

}

4 运行启动类

Application

package li.chen.com;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import tk.mybatis.spring.annotation.MapperScan;

/**
 * @MapperScan 扫描mybatis所有业务的mapper接口，等同于在UserMapper接口 上 @Mapper
 **/
@SpringBootApplication
@MapperScan("li.chen.com.mapper") //注意使用tk的包
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

查看结果

刷新请求路径
http://localhost/user/2