将上一篇Spring Boot整合Mybatis 修改为Mybatis-plus

Mybatis-plus我就不多做介绍了 直接百度搜索了解一下

首先将pom.xml 中的 mybatis-spring-boot-starter 换成 mybatisplus-spring-boot-starter

<!--<dependency>-->
    <!--<groupId>org.mybatis.spring.boot</groupId>-->
    <!--<artifactId>mybatis-spring-boot-starter</artifactId>-->
    <!--<version>1.3.0</version>-->
<!--</dependency>-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatisplus-spring-boot-starter</artifactId>
    <version>1.0.4</version>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus</artifactId>
    <version>2.1-gamma</version>
</dependency>

然后将Mybatis配置 换成 Mybatis-plus配置
完全兼容Mybatis的所有配置

# Mybatis配置
#mybatis:
#    mapperLocations: classpath:mapper/**/*.xml
#    typeAliasesPackage: com.xiaohan.bootdemo.entity
#    #config-location: classpath:mybatis.xml
#    configuration:
#      map-underscore-to-camel-case: true  #使用驼峰法映射属性

# Mybatis-plus配置
mybatis-plus:
  mapper-locations: classpath:mapper/**/*.xml
  typeAliasesPackage: com.xiaohan.bootdemo.entity
  configuration:
    map-underscore-to-camel-case: true  #使用驼峰法映射属性
  global-config:
    #主键类型  0:"数据库ID自增", 1:"用户输入ID",2:"全局唯一ID (数字类型唯一ID)", 3:"全局唯一ID UUID";
    id-type: 0
    #字段策略 0:"忽略判断",1:"非 NULL 判断"),2:"非空判断"
    field-strategy: 2
    #驼峰下划线转换
    db-column-underline: true
    #刷新mapper 调试神器
    refresh-mapper: true
    #数据库大写下划线转换
    #capital-mode: true
    #序列接口实现类配置
    #key-generator: com.baomidou.springboot.xxx
    #逻辑删除配置
    #logic-delete-value: 0
    #logic-not-delete-value: 1
    #自定义填充策略接口实现
    #meta-object-handler: com.baomidou.springboot.xxx
    #自定义SQL注入器
    #sql-injector: com.baomidou.springboot.xxx

可以完全兼容mybatis的

现在来试一下plus的api

将dao接口 里面的方法全部删除 并继承BaseMapper指定实体泛型

package com.xiaohan.bootdemo.dao;

import com.baomidou.mybatisplus.mapper.BaseMapper;
import com.xiaohan.bootdemo.entity.UserEntity;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

@Repository
@Mapper
public interface UserDao extends BaseMapper<UserEntity> {
}

修改实体类如下
继承Model指定泛型为本类
在类上使用@TableName指定映射的表
在主键id上使用@TableId主键 指定主键策略 此处优先级 比 全局配置要高
主键必须存在 且 不支持复合主键
实现pkVal方法返回主键

package com.xiaohan.bootdemo.entity;

import com.baomidou.mybatisplus.activerecord.Model;
import com.baomidou.mybatisplus.annotations.TableId;
import com.baomidou.mybatisplus.annotations.TableName;
import com.baomidou.mybatisplus.enums.IdType;

import java.io.Serializable;
import java.util.Date;

@TableName("t_user")
public class UserEntity extends Model<UserEntity> implements Serializable {

    @TableId(value = "id", type = IdType.AUTO)
    private Integer id;
    private String name;
    private Date createTime;

    //省略set get方法

    @Override
    protected Serializable pkVal() {
        return this.id;
    }

    @Override
    public String toString() {
        return "UserEntity{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", createTime=" + createTime +
                '}';
    }
}

测试类如下 更多API请访问mybatis-plus github仓库查看

package com.xiaohan.bootdemo;

import com.xiaohan.bootdemo.dao.UserDao;
import com.xiaohan.bootdemo.entity.UserEntity;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.Date;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class BootdemoApplicationTests {

    @Autowired
    private UserDao userDao;

    @Test
    public void insertTest() {
        UserEntity userEntity = new UserEntity();
        userEntity.setName("李四");
        Integer i = userDao.insert(userEntity);
        Integer id = userEntity.getId();
        System.err.println("影响行数==>" + i);
        System.err.println("id==>" + id);
    }

    @Test
    public void selectAllTest() {
        List<UserEntity> list = userDao.selectList(null);
        for (UserEntity userEntity:
             list) {
            System.err.println(userEntity);
        }
    }


    @Test
    public void selectByIdTest() {
        UserEntity userEntity = userDao.selectById(1);
        System.err.println(userEntity);
    }

    @Test
    public void deleteTest() {
        int i = userDao.deleteById(1);
        System.err.println("影响行数==>" + i);
        selectAllTest();
    }

    @Test
    public void updateByIdTest() {
        UserEntity userEntity = new UserEntity();
        userEntity.setId(2);
        userEntity.setName("王五");
        userEntity.setCreateTime(new Date());
        int i = userDao.updateById(userEntity);
        System.err.println("影响行数==>" + i);
        selectAllTest();
    }
}