springboot整合mybatis

springboot整合mybatis

1、导包

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.11</version>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.2</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-configuration-processor</artifactId>
    <optional>true</optional>
</dependency>

2、实体类

package com.yl.bean;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.Date;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Employee {
    private Integer id;
    private String name;
    private String email;
    private Date hiredate;
}

3、业务层接口

package com.yl.service;

import com.yl.bean.Employee;
import java.util.List;

public interface IEmployeeService {
    /**
     * 查询所有
     */
    List<Employee> queryAll();

}

4、业务层接口实现类

package com.yl.service.impl;

import com.yl.bean.Employee;
import com.yl.mapper.IEmployeeMapper;
import com.yl.service.IEmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class IEmployeeServiceImpl implements IEmployeeService {
    @Autowired
    private IEmployeeMapper employeeMapper;

    /**
     * 查询所有
     */
    @Override
    public List<Employee> queryAll() {
        return employeeMapper.queryAll();
    }
}

5、持久层接口

package com.yl.mapper;

import com.yl.bean.Employee;
import org.springframework.stereotype.Repository;
import java.util.List;

// 推荐使用@mapper，启动类上就不用加注解指定mapper位置了
@Repository 
public interface IEmployeeMapper {

    /**
     * 查询所有
     */
    List<Employee> queryAll();

}

6、持久层映射文件

<?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.yl.mapper.IEmployeeMapper">
    <!--查询所有-->
    <select id="queryAll" resultType="com.yl.bean.Employee">
        select * from employee
    </select>
</mapper>

7、配置文件

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    password: 123456
    username: root
    url: jdbc:mysql://localhost:3306/spring?characterEncoding=utf8&serverTimezone=GMT%2B8
    type: com.alibaba.druid.pool.DruidDataSource # 指定数据源类型
mybatis:
  mapper-locations: classpath:mapper/*.xml # 指定持久层映射文件的位置

8、编写配置类配置数据源

package com.yl.configration;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

@Configuration
public class DruidConfig {

    /**
     * 将自定义的 Druid数据源添加到容器中，不再让 Spring Boot 自动创建
     * 绑定全局配置文件中的 druid 数据源属性到 com.alibaba.druid.pool.DruidDataSource从而让它们生效
     * @ConfigurationProperties(prefix = "spring.datasource")：作用就是将 全局配置文件中
     * 前缀为 spring.datasource的属性值注入到 com.alibaba.druid.pool.DruidDataSource 的同名参数中
     * @return
     */
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource druidDataSource() {
        return new DruidDataSource();
    }
}

9、启动类

package com.yl;

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

@SpringBootApplication
// 扫描持久层接口，如果持久层使用@mapper注解则不用扫描
@MapperScan(basePackages = "com.yl.mapper")
public class Springboot03Application {

    public static void main(String[] args) {
        SpringApplication app = new SpringApplication(Springboot03Application.class);
        app.setBannerMode(Banner.Mode.OFF);
        app.run(args);
    }

}