Springboot集成Mybatis-puls

1.Mybatis-plus特点

• 无侵入：只做增强不做改变，引入它不会对现有工程产生影响，如丝般顺滑
• 损耗小：启动即会自动注入基本 CURD，性能基本无损耗，直接面向对象操作
• 强大的 CRUD 操作：内置通用 Mapper、通用 Service，仅仅通过少量配置即可实现单表大部分 CRUD 操作， 更有强大的条件构造器，满足各类使用需求
• 支持 Lambda 形式调用：通过 Lambda 表达式，方便的编写各类查询条件，无需再担心字段写错
• 支持多种数据库：支持 MySQL、MariaDB、Oracle、DB2、H2、HSQL、SQLite、Postgre、 SQLServer2005、SQLServer 等多种数据库
• 支持主键自动生成：支持多达 4 种主键策略（内含分布式唯一 ID 生成器 - Sequence），可自由配置，完美解 决主键问题
• 支持 XML 热加载：Mapper 对应的 XML 支持热加载，对于简单的 CRUD 操作，甚至可以无 XML 启动 - 支持 ActiveRecord 模式：支持 ActiveRecord 形式调用，实体类只需继承 Model 类即可进行强大的 CRUD 操 作
• 支持自定义全局通用操作：支持全局通用方法注入（ Write once, use anywhere ）
• 支持关键词自动转义：支持数据库关键词（order、key…）自动转义，还可自定义关键词
• 内置代码生成器：采用代码或者 Maven 插件可快速生成 Mapper 、 Model 、 Service 、 Controller 层代码， 支持模板引擎，更有超多自定义配置等您来使用
• 内置分页插件：基于 MyBatis 物理分页，开发者无需关心具体操作，配置好插件之后，写分页等同于普通 List 查询
• 内置性能分析插件：可输出 Sql 语句以及其执行时间，建议开发测试时启用该功能，能快速揪出慢查询 - 内置全局拦截插件：提供全表 delete 、 update 操作智能分析阻断，也可自定义拦截规则，预防误操作 - 内置 Sql 注入剥离器：支持 Sql 注入剥离，有效预防 Sql 注入攻击

2. 架构

3.作者

Mybatis-Plus是由baomidou（苞米豆）组织开发并且开源的，目前该组织大概有30人左右。 码云地址：https://gitee.com/organizations/baomidou

4.快速开始

sql语句

-- 创建测试表
CREATE TABLE `tb_user` (
  `id` BIGINT(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID', 
  `user_name` VARCHAR(20) NOT NULL COMMENT '用户名',
  `password` VARCHAR(20) NOT NULL COMMENT '密码',  
  `name` VARCHAR(30) DEFAULT NULL COMMENT '姓名',  
  `age` INT(11) DEFAULT NULL COMMENT '年龄',  
  `email` VARCHAR(50) DEFAULT NULL COMMENT '邮箱',  
  PRIMARY KEY (`id`) ) ENGINE=INNODB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
-- 插入测试数据
INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES 
('1', 'zhangsan', '123456', '张三', '18', '[email protected]'); 
INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES 
('2', 'lisi', '123456', '李四', '20', '[email protected]'); 
INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES 
('3', 'wangwu', '123456', '王五', '28', '[email protected]'); 
INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES 
('4', 'zhaoliu', '123456', '赵六', '21', '[email protected]'); 
INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES 
('5', 'sunqi', '123456', '孙七', '24', '[email protected]');

项目结构

导入依赖

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.capgemini</groupId>
    <artifactId>springboot_mybatisplus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot_mybatisplus</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--简化代码的工具包-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--mybatis-plus的springboot支持-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.1</version>
        </dependency>
        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

User类

package com.capgemini.pojo;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
//@TableName("tb_user")
public class User {

//    @TableId(type = IdType.AUTO)
    private Long id;
    private String userName;

    @TableField(select = false) //查询时不返回该字段的值
    private String password;
    private String name;
    private Integer age;

    @TableField(value = "email") //指定数据表中字段名
    private String mail;

    @TableField(exist = false)
    private String address; //在数据库表中是不存在的
}

UserMapper类

package com.capgemini.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.capgemini.pojo.User;

public interface UserMapper extends BaseMapper<User> {

    User findById(Long id);

}

MybatisPlusConfig类

package com.capgemini.config;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@MapperScan("com.capgemini.mapper") //设置mapper接口的扫描包
public class MybatisPlusConfig {


    @Bean //配置分页插件
    public PaginationInterceptor paginationInterceptor(){
        return new PaginationInterceptor();
    }
}

application.properties

```java
spring.application.name = itcast-mp-springboot

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://rm-2ze3k6ugj5013171s7o.mysql.rds.aliyuncs.com:3306/work?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false
spring.datasource.username=
spring.datasource.password=

# 指定全局的配置文件
#mybatis-plus.config-location=classpath:mybatis-config.xml
# 指定Mapper.xml文件的路径
mybatis-plus.mapper-locations = classpath*:mybatis/*.xml
# 实体对象的扫描包
mybatis-plus.type-aliases-package = com.capgemini.pojo

# 禁用自定的驼峰映射
mybatis-plus.configuration.map-underscore-to-camel-case=true

# 禁用缓存
mybatis-plus.configuration.cache-enabled=false

# 全局的id生成策略
mybatis-plus.global-config.db-config.id-type=auto

# 全局的表名的前缀
mybatis-plus.global-config.db-config.table-prefix=tb_

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.capgemini.mapper.UserMapper">

    <select id="findById" resultType="com.capgemini.pojo.User">
        select * from tb_user where id = #{id}
    </select>

</mapper>

log4j.properties

log4j.rootLogger=DEBUG,A1

log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=[%t] [%c]-[%p] %m%n

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
    <!--<plugins>-->
        <!--<plugin interceptor="com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor"></plugin>-->
    <!--</plugins>-->

</configuration>

5测试

TestMybatisSpringBoot

package com.capgemini;

import com.capgemini.mapper.UserMapper;
import com.capgemini.pojo.User;
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.SpringJUnit4ClassRunner;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class TestMybatisSpringBoot {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void testSelectList(){
        List<User> users = this.userMapper.selectList(null);
        for (User user : users) {
            System.out.println(user);
        }
    }

}

TestUserMapper

package com.capgemini;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.capgemini.mapper.UserMapper;
import com.capgemini.pojo.User;
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.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

    @Autowired
    private UserMapper userMapper;

    @Test
    public void testInsert() {
        User user = new User();
        user.setMail("2capgemini.com");
        user.setAge(301);
        user.setUserName("caocao1");
        user.setName("曹操1");
        user.setPassword("123456");
        user.setAddress("北京");

        int result = this.userMapper.insert(user); //result数据库受影响的行数
        System.out.println("result => " + result);

        //获取自增长后的id值, 自增长后的id值会回填到user对象中
        System.out.println("id => " + user.getId());
    }

    @Test
    public void testSelectById() {
        User user = this.userMapper.selectById(2L);
        System.out.println(user);
    }

    @Test
    public void testUpdateById() {
        User user = new User();
        user.setId(1L); //条件，根据id更新
        user.setAge(19); //更新的字段
        user.setPassword("666666");

        int result = this.userMapper.updateById(user);
        System.out.println("result => " + result);
    }

    @Test
    public void testUpdate() {
        User user = new User();
        user.setAge(20); //更新的字段
        user.setPassword("8888888");

        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.eq("user_name", "zhangsan"); //匹配user_name = zhangsan 的用户数据

        //根据条件做更新
        int result = this.userMapper.update(user, wrapper);
        System.out.println("result => " + result);
    }

    @Test
    public void testUpdate2() {

        UpdateWrapper<User> wrapper = new UpdateWrapper<>();
        wrapper.set("age", 21).set("password", "999999") //更新的字段
                .eq("user_name", "zhangsan"); //更新的条件

        //根据条件做更新
        int result = this.userMapper.update(null, wrapper);
        System.out.println("result => " + result);
    }

    @Test
    public void testDeleteById() {
        // 根据id删除数据
        int result = this.userMapper.deleteById(9L);
        System.out.println("result => " + result);
    }

    @Test
    public void testDeleteByMap() {

        Map<String, Object> map = new HashMap<>();
        map.put("user_name", "zhangsan");
        map.put("password", "999999");

        // 根据map删除数据，多条件之间是and关系
        int result = this.userMapper.deleteByMap(map);
        System.out.println("result => " + result);
    }

    @Test
    public void testDelete() {

        //用法一：
//        QueryWrapper wrapper = new QueryWrapper<>();
//        wrapper.eq("user_name", "caocao1")
//                .eq("password", "123456");

        //用法二：
        User user = new User();
        user.setPassword("123456");
        user.setUserName("caocao");

        QueryWrapper<User> wrapper = new QueryWrapper<>(user);

        // 根据包装条件做删除
        int result = this.userMapper.delete(wrapper);
        System.out.println("result => " + result);
    }

    @Test
    public void testDeleteBatchIds() {
        // 根据id批量删除数据
        int result = this.userMapper.deleteBatchIds(Arrays.asList(10L, 11L));
        System.out.println("result => " + result);
    }

    @Test
    public void testSelectBatchIds() {
        // 根据id批量查询数据
        List<User> users = this.userMapper.selectBatchIds(Arrays.asList(2L, 3L, 4L, 100L));
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testSelectOne() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //查询条件
        wrapper.eq("password", "123456");
        // 查询的数据超过一条时，会抛出异常
        User user = this.userMapper.selectOne(wrapper);
        System.out.println(user);
    }

    @Test
    public void testSelectCount() {

        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.gt("age", 20); // 条件：年龄大于20岁的用户

        // 根据条件查询数据条数
        Integer count = this.userMapper.selectCount(wrapper);
        System.out.println("count => " + count);
    }

    @Test
    public void testSelectList() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //设置查询条件
        wrapper.like("email", "itcast");

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }
    }

    // 测试分页查询
    @Test
    public void testSelectPage() {

        Page<User> page = new Page<>(3, 1); //查询第一页，查询1条数据

        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //设置查询条件
        wrapper.like("email", "itcast");

        IPage<User> iPage = this.userMapper.selectPage(page, wrapper);
        System.out.println("数据总条数： " + iPage.getTotal());
        System.out.println("数据总页数： " + iPage.getPages());
        System.out.println("当前页数： " + iPage.getCurrent());

        List<User> records = iPage.getRecords();
        for (User record : records) {
            System.out.println(record);
        }

    }

    /**
     * 自定义的方法
     */
    @Test
    public void testFindById() {
        User user = this.userMapper.findById(2L);
        System.out.println(user);
    }

    @Test
    public void testAllEq() {

        Map<String, Object> params = new HashMap<>();
        params.put("name", "李四");
        params.put("age", "20");
        params.put("password", null);

        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //SELECT id,user_name,name,age,email AS mail FROM tb_user WHERE password IS NULL AND name = ? AND age = ?
//        wrapper.allEq(params);
        //SELECT id,user_name,name,age,email AS mail FROM tb_user WHERE name = ? AND age = ?
//        wrapper.allEq(params, false);

        //SELECT id,user_name,name,age,email AS mail FROM tb_user WHERE age = ?
//        wrapper.allEq((k, v) -> (k.equals("age") || k.equals("id")) , params);
        //SELECT id,user_name,name,age,email AS mail FROM tb_user WHERE name = ? AND age = ?
        wrapper.allEq((k, v) -> (k.equals("age") || k.equals("id") || k.equals("name")), params);

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testEq() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();

        //SELECT id,user_name,password,name,age,email FROM tb_user WHERE password = ? AND age >= ? AND name IN (?,?,?)
        wrapper.eq("password", "123456")
                .ge("age", 20)
                .in("name", "李四", "王五", "赵六");

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }

    }

    @Test
    public void testLike() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        // SELECT id,user_name,name,age,email AS mail FROM tb_user WHERE name LIKE ?
        // 参数：%五(String)
        wrapper.likeLeft("name", "五");

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testOrderByAgeDesc() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //按照年龄倒序排序
        // SELECT id,user_name,name,age,email AS mail FROM tb_user ORDER BY age DESC
        wrapper.orderByDesc("age");

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testOr() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        // SELECT id,user_name,name,age,email AS mail FROM tb_user WHERE name = ? OR age = ?
        wrapper.eq("name", "王五").or().eq("age", 21);

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testSelect() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //SELECT id,name,age FROM tb_user WHERE name = ? OR age = ?
        wrapper.eq("name", "王五")
                .or()
                .eq("age", 21)
                .select("id", "name", "age"); //指定查询的字段

        List<User> users = this.userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user);
        }
    }

}

源码

https://gitee.com/du_jing_tao/springbootmybatis.git