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。
创建项目,
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>
配置配置文件:
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: root
driver-class-name: com.mysql.jdbc.Driver
mybatis:
mapper-locations: classpath:mapper/*.xml
type-aliases-package: com.chaoqi.springboot_mybatisplus.domain
逆向生成文件:
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="C:/Users/Administrator/.m2/repository/mysql/mysql-connector-java/5.1.6/mysql-connector-java-5.1.6.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="root">
</jdbcConnection>
<!-- 生成实体类地址 -->
<javaModelGenerator targetPackage="com.mybatisplus.mybatisplustest.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.mybatisplus.mybatisplustest.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>
需要修改其中的<classPathEntry>中的路径,<jdbcConnection>中的数据库配置,以及下面三个生成路径
然后找到该文件并运行,根据表生成文件
如果这里报错,根据报错信息查看是否配置文件有错误
生成的结构:
创建Service和Controller,不需要手写SQL语句
public interface UserInfoService {
public List<UserInfo> getMusicInfo();
}
@Service
public class UserInfoServiceImpl implements UserInfoService {
@Autowired
private UserInfoMapper userInfoMapper;
@Override
public List<UserInfo> getMusicInfo() {
List<UserInfo> userInfos = userInfoMapper.selectAll();
return userInfos;
}
}
@RestController
public class UserinfoController {
@Autowired
private UserInfoService userInfoService;
@RequestMapping("/alluser")
public List<UserInfo> getUserInfo() {
List<UserInfo> musicInfo1 = userInfoService.getMusicInfo();
return musicInfo1;
}
}
在启动类上配置mapper
@SpringBootApplication
@MapperScan("com.mybatisplus.mybatisplustest.dao.mapper")
public class MybatisplustestApplication {
public static void main(String[] args) {
SpringApplication.run(MybatisplustestApplication.class, args);
}
}
然后启动测试