Spring boot集成Mybatis-Plus，通用Mapper
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：
接下来整合MybatisPlus：
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
注意：
// Caused by: tk.mybatis.mapper.MapperException: id - 该字段@GeneratedValue配置只允许以下几种形式: // 1.全部数据库通用的@GeneratedValue(generator="UUID") // 2.useGeneratedKeys的@GeneratedValue(generator=\"JDBC\") // 3.类似mysql数据库的@GeneratedValue(strategy=GenerationType.IDENTITY[,generator="Mysql"])
