SpringBoot快速入门

Posted 2020-11-27 陌星

SpringBoot集成MyBatis

SpringBoot集成MyBatis

属于数据访问层；MyBatis所有的包都是自己的，所以要导入自己的依赖

1、导入驱动和依赖

        <!-- 这是自定义的包 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.1</version>
        </dependency>
        <!-- mysql 驱动 可以用自己的版本-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

2、编写配置文件：application.yaml(在resources目录下)

spring:
    datasource:
      username: root
      password: 123456
      url: jdbc:mysql://localhost:3306/mybatis?useSSL=true&userUnicode=true&characterEncoding=utf-8
      driver-class-name: com.mysql.jdbc.Driver

  # mysql5 com.mysql.jdbc.Driver
  # mysql8 com.mysql.cj.jdbc.Driver 必须要在url连接中编写时区 serverTimezone=UTC

3、测试数据源是否已经配置成功，在测试类中测试

package com.star;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootTest
class SpringbootApplicationTests {

    // 自动导入数据源
    @Autowired
    private DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {
        //查看默认数据源 class com.zaxxer.hikari.HikariDataSource
        System.out.println(dataSource.getClass());
        //获取连接
        Connection connection = dataSource.getConnection();
        //关闭
        connection.close();
    }

}

SpringBoot 目前默认的数据源是 class com.zaxxer.hikari.HikariDataSource

4、编写实体类

package com.star.pojo;

import lombok.Data;

@Data
public class User {
    private int id;
    private String name;
    private String pwd;
}

5、编写mapper接口(使用注解或者xml都可以)

package com.star.mapper;

import com.star.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper //标注这个一个mapper接口
@Repository //代表持久层
public interface UserMapper {

//    @Value("select * from user")
    List<User> getUserList();
}

配置文件中要添加mybatis配置

mybatis:
  type-aliases-package: com.star.pojo
  mapper-locations: classpath:com/star/mapper/*.xml

6、编写资源过滤

        <!--配置资源过滤
         true 可以被过滤，即可以根据profile进行属性替换
         false 能被编译打包，即能够被复制到classpath目录下
         -->
        <resources>
            <resource>
                <filtering>true</filtering>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>

7、编写测试类

package com.star.controller;

import com.star.mapper.UserMapper;
import com.star.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class MyBatisController {

    @Autowired //自动注入接口
    private UserMapper userMapper;

    @RequestMapping("list")
    public List getUserList(){
        List<User> userList = userMapper.getUserList();
        return userList;
    }
}

测试结果：

我们可得出结论：只需要编写对应的配置文件，导入对应的依赖就可以用了！