SpringBoot-13-整合MyBatis

2020-04-01

字数统计: 887字 | 阅读时长≈ 4分钟

SpringBoot-13-整合MyBatis

1. 简介

官方文档：http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/
Maven仓库地址：https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter/2.1.1
底层使用：当然还是JDBC

只不过是在JDBC上整合了一个框架
使用的数据源依旧是SpringBoot默认的数据源（Hikari）

2. Druid Mybatis 整合测试

导入 MyBatis 所需要的依赖

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

配置数据库连接信息（不变）

spring:
  datasource:
    username: root
    password: 123456
    #?serverTimezone=UTC解决时区的报错
    url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
    driver-class-name: com.mysql.cj.jdbc.Driver									# jdbc的数据源：Hikari
    type: com.alibaba.druid.pool.DruidDataSource                # 这边整合alibaba的Druid

    #Spring Boot 默认是不注入这些属性值的，需要自己绑定
    #druid 数据源专有配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true

    #配置监控统计拦截的filters，stat:监控统计、log4j：日志记录、wall：防御sql注入
    #如果允许时报错  java.lang.ClassNotFoundException: org.apache.log4j.Priority
    #则导入 log4j 依赖即可，Maven 地址：https://mvnrepository.com/artifact/log4j/log4j
    filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

测试数据库是否连接成功！
创建实体类并导入lombook!

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

@Data
@NoArgsConstructor
@AllArgsConstructor
// 1. Mapper对应的实体类，数据库映射对象
public class User {

    private int id;
    private String pwd;
}

创建Mapper目录以及对应的Mapper接口

import com.zhuuu.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

//1. Mapper这个注解表示了这是一个mybatis的mapper类:
//2. 同时这也是一个Dao接口，CRUD方法
@Mapper
@Repository
public interface UserMapper {
//    public static final int age = 18;				=== int age = 18; //Java语法别忘了

  	// CRUD的方法
    List<User> queryUserlist();

    User queryUserById(int id);

    int addUser(User user);

    int updateUser(User user);

    int deleteUser(int id);

}

对应的Mapper映射文件（与之前不同的是统一放在resources/mapper/UserMapper.xml）

<?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.zhuuu.mapper.UserMapper">

    <select id="queryUserlist" resultType="User">
        select * from user
    </select>

    <select id="queryUserById" resultType="User">
        select * from user where id = #{id}
    </select>

    <insert id="addUser" parameterType="User">
        insert into user(id, name, pwd) values (#{id},#{name},#{pwd})
    </insert>

    <update id="updateUser" parameterType="User">
        update user set name=#{name},pwd=#{pwd} where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from user where id=#{id}
    </delete>

</mapper>

Maven配置资源过滤问题

<resources>
    <resource>
        <directory>src/main/java</directory>
        <includes>
            <include>**/*.xml</include>
        </includes>
        <filtering>true</filtering>
    </resource>
</resources>

编写UserController进行测试

@RestController
public class UserController {

  	// 这里本应该注入Service层
    @Autowired
    private UserMapper userMapper;

    @GetMapping("/queryUserList")
    public List<User> queryUserList(){
        List<User> userList = userMapper.queryUserlist();			// Mapper已经通过Spring自动注入
        for (User user : userList) {
            System.out.println(user);
        }
        return userList;
    }
    
}