springboot集成mybatisplus的方法

介绍：

Mybatis-Plus（简称MP）是一个 Mybatis 的增强工具，在 Mybatis 的基础上只做增强不做改变，为简化开发、提高效率而生。（摘自mybatis-plus官网）Mybatis虽然已经给我们提供了很大的方便，但它还是有不足之处，MP的存在就是为了稍稍弥补Mybatis的不足。在我们使用Mybatis时会发现，每当要写一个业务逻辑的时候都要在DAO层写一个方法，再对应一个SQL，即使是简单的条件查询、即使仅仅改变了一个条件都要在DAO层新增一个方法，针对这个问题，MP这样一个框架，一种集Mybatis与Hibernate的优点一起的框架。它提供了Hibernate的单表CURD操作的方便同时，又保留了Mybatis的特性。

本章只教大家怎么使用MybatisPlus，如果想深入了解底层是怎么实现的可以去官网下载源代码进行解读。

一、创建项目

　　这里就不一步一步来了，我直接给出创建后的项目结构，在本章的最后我会给出源码地址需要看效果的可以进行下载。

二、引入依赖

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>

 <groupId>com.chaoqi</groupId>
 <artifactId>springboot_mybatisplus</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>jar</packaging>

 <name>springboot_mybatisplus</name>
 <description>Demo project for Spring Boot</description>

 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.0.0.RELEASE</version>
  <relativePath/>
 </parent>

 <properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
  <java.version>1.8</java.version>
 </properties>

 <dependencies>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-jdbc</artifactId>
  </dependency>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>1.3.2</version>
  </dependency>

  <dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <scope>runtime</scope>
  </dependency>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
   <scope>test</scope>
  </dependency>
  <!--添加jsp依赖 -->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-tomcat</artifactId>
  </dependency>
  <dependency>
   <groupId>org.apache.tomcat.embed</groupId>
   <artifactId>tomcat-embed-jasper</artifactId>
  </dependency>
  <!-- SpringBoot - MyBatis 逆向工程 -->
  <dependency>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-core</artifactId>
   <version>1.3.2</version>
  </dependency>

  <!-- MyBatis 通用 Mapper -->
  <dependency>
   <groupId>tk.mybatis</groupId>
   <artifactId>mapper-spring-boot-starter</artifactId>
   <version>1.1.4</version>
  </dependency>
 </dependencies>

 <build>
  <plugins>
   <plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
   </plugin>
   <plugin>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-maven-plugin</artifactId>
    <version>1.3.2</version>
    <configuration>
     <configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
     <verbose>true</verbose>
     <overwrite>true</overwrite>
    </configuration>
    <executions>
     <execution>
      <id>Generate MyBatis Artifacts</id>
      <goals>
       <goal>generate</goal>
      </goals>
     </execution>
    </executions>
    <dependencies>
     <dependency>
      <groupId>org.mybatis.generator</groupId>
      <artifactId>mybatis-generator-core</artifactId>
      <version>1.3.2</version>
     </dependency>
     <dependency>
      <groupId>tk.mybatis</groupId>
      <artifactId>mapper</artifactId>
      <version>3.5.0</version>
     </dependency>
    </dependencies>
   </plugin>
  </plugins>
 </build>

</project>

三、编辑application.yml

server:
 port: 8080

spring:
 mvc:
 view:
  prefix: /WEB-INF/jsp/
  suffix: .jsp
 datasource:
 url: jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8&useUnicode=true&useSSL=false
 username: root
 password: 123456
 driver-class-name: com.mysql.jdbc.Driver

mybatis:
 mapper-locations: classpath:mapper/*.xml
 type-aliases-package: com.chaoqi.springboot_mybatisplus.domain

四、逆向生成pojo，mapper

创建generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
  PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
  "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>

 <properties resource="application.yml"/>
 <classPathEntry location="D:/mysql/mysql-connector-java-5.1.46/mysql-connector-java-5.1.46.jar"/>
 <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
  <property name="beginningDelimiter" value="`"/>
  <property name="endingDelimiter" value="`"/>
  <property name="javaFileEncoding" value="UTF-8"/>
  <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
   <property name="mappers" value="tk.mybatis.mapper.common.Mapper"/>
  </plugin>
  <!-- 注释 -->
  <commentGenerator>
   <!-- 是否生成注释代时间戳 -->
   <property name="suppressDate" value="true"/>
   <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
   <property name="suppressAllComments" value="false"/>
  </commentGenerator>
  <!-- JDBC连接 -->
  <jdbcConnection
    driverClass="com.mysql.jdbc.Driver"
    connectionURL="jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8"
    userId="root"
    password="123456">
  </jdbcConnection>
  <!-- 生成实体类地址 -->
  <javaModelGenerator targetPackage="com.chaoqi.springboot_mybatisplus.dao.domain" targetProject="src/main/java"/>
  <!-- 生成mapper xml文件 -->
  <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources"/>
  <!-- 生成mapper xml对应Client-->
  <javaClientGenerator targetPackage="com.chaoqi.springboot_mybatisplus.dao.mapper" targetProject="src/main/java"
        type="XMLMAPPER"/>
  <!-- 配置表信息 -->
  <table tableName="%">
   <!--mysql 配置-->
   <generatedKey column="id" sqlStatement="Mysql"/>
   <!--oracle 配置-->
   <!--<generatedKey column="id" sqlStatement="select SEQ_{1}.nextval from dual" identity="false" type="pre"/>-->
  </table>
 </context>
</generatorConfiguration>

maven运行generator

生成完后的项目结构如下

五、整合mybatisplus

创建service接口以及service实现类

package com.chaoqi.springboot_mybatisplus.service;

import com.chaoqi.springboot_mybatisplus.dao.domain.MusicInfo;
import java.util.List;
public interface MusicInfoService {
 public List<MusicInfo> getMusicInfo();
}

package com.chaoqi.springboot_mybatisplus.service.impl;

import com.chaoqi.springboot_mybatisplus.dao.domain.MusicInfo;
import com.chaoqi.springboot_mybatisplus.dao.mapper.MusicInfoMapper;
import com.chaoqi.springboot_mybatisplus.service.MusicInfoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class MusicInfoServiceImpl implements MusicInfoService {

 @Autowired
 private MusicInfoMapper musicInfoMapper;

 @Override
 public List<MusicInfo> getMusicInfo() {
  List<MusicInfo> musicInfos = musicInfoMapper.selectAll();
  return musicInfos;
 }
}

创建Controller

package com.chaoqi.springboot_mybatisplus.web;

import com.chaoqi.springboot_mybatisplus.dao.domain.MusicInfo;
import com.chaoqi.springboot_mybatisplus.service.MusicInfoService;
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
@RequestMapping(value = "/music")
public class MusicInfoController {

 @Autowired
 private MusicInfoService musicInfoService;

 @RequestMapping("/showMusic")
 public List<MusicInfo> getMusicInfo() {
  List<MusicInfo> musicInfo1 = musicInfoService.getMusicInfo();
  return musicInfo1;
 }

}

这里我的mapper并不要写sql，一些简单的sqlmybatiplus都给封装好了，节省了许多开发时间，如果是一些复杂的sql，也可以通过写原生sql来实现，在我的第二篇博客中有讲到springboot+springmvc+mybatis项目整合

运行SpringbootMybatisplusApplication主函数

package com.chaoqi.springboot_mybatisplus;

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

@SpringBootApplication
@MapperScan("com.chaoqi.springboot_mybatisplus.dao.mapper")
public class SpringbootMybatisplusApplication {

 public static void main(String[] args) {
  SpringApplication.run(SpringbootMybatisplusApplication.class, args);
 }
}

查看数据库

下面给出mybatisplus封装的一些方法，这些方法具体怎么使用，感兴趣的小伙伴可以查看下源代码，mybatisplus还有一个强大的分页功能，如果有兴趣也可以去这里学习

（源码下载地址）

最后谢谢大家的观看，写博客经验不足，写得不好请见谅