通用mapper就是指的是 tk.mybatis 包下的。这个是通用mapper就是说自动生成的dao层需要继承这个框架提供的mapper类。而我们之前用的org.mybatis这个最开始是普通的。
就是说最开始我们用这个会给我们生成dao接口（不继承其他类），mapper文件（有许多方法增删改查）和实体类。我们感觉很麻烦，所以就出来了通用mapper，只需要继承mapper类就行，自动有增删改查的方法，类似于jpa。代码很简洁。我们这里只讲一下如何自动生成。
坑很多，比如说springboot2.0以上就会出问题，换成1.5就可以。要按照教程来。肯定会成功的。
pom文件
<?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.example</groupId> <artifactId>tk-mybatis</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>tk-mybatis</name> <description>Demo project <span style="color: #0000ff;">for</span> Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.10.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </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-web</artifactId> </dependency> <!--mybatis--> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <!--mysql驱动--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <!-- mybatis 逆向生成工具 --> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.2</version> <scope>compile</scope> <optional><span style="color: #0000ff;">true</span></optional> </dependency> <!--mapper --> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>1.2.4</version> </dependency> <!--数据库连接池--> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </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> <!--generator配置文件所在位置--> <configurationFile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile> <verbose><span style="color: #0000ff;">true</span></verbose> <overwrite><span style="color: #0000ff;">true</span></overwrite> </configuration> <dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.36</version> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper</artifactId> <version>3.4.0</version> </dependency> </dependencies> </plugin> </plugins> </build>
</project>
generatorConfig.properties
# Generator generator.targetProject=src/main/java generator.mappers=com.example.demo.baseMapper.IBaseMapper generator.javaModel-targetPackage=com.example.demo.domain generator.sqlMap-targetPackage=com.example.demo.dao generator.javaClient-targetPackage=com.example.demo.dao
#mysql
driverClass=com.mysql.jdbc.Driver
connectionURL=jdbc:mysql://localhost:3306/video?serverTimezone=UTC
userId=root
password=root
generatorConfig.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"> <!--根节点 --> <generatorConfiguration> <!-- 指定外部的属性元素 --> <properties resource="generatorConfig.properties"/> <!-- 必须 指定生成一组对象的环境 --> <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat"> <!--分隔符 --> <property name="autoDelimitKeywords" value="true"/> <property name="beginningDelimiter" value="`"/> <property name="endingDelimiter" value="`"/><!-- 通用mapper插件 --> <plugin type="tk.mybatis.mapper.generator.MapperPlugin"> <!-- 此处的 MyMapper注意一定不能被扫描到--> <property name="mappers" value="${generator.mappers}"/> </plugin> <!-- 注释 规则--> <commentGenerator> <property name="suppressAllComments" value="false"/> <property name="suppressDate" value="true"/> </commentGenerator> <jdbcConnection driverClass="${driverClass}"<span style="color: #000000;"> connectionURL</span>="${connectionURL}"<span style="color: #000000;"> userId</span>="${userId}"<span style="color: #000000;"> password</span>="${password}"> </jdbcConnection> <javaModelGenerator targetPackage="${generator.javaModel-targetPackage}" targetProject="${generator.targetProject}"/> <sqlMapGenerator targetPackage="${generator.sqlMap-targetPackage}" targetProject="${generator.targetProject}"/> <javaClientGenerator targetPackage="${generator.javaClient-targetPackage}" targetProject="${generator.targetProject}"<span style="color: #000000;"> type</span>="XMLMAPPER"/> <table tableName="bgm"> <!--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>
IBaseMapper（让生成的mapper接口都继承这个类）
package com.example.demo.baseMapper;
import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;
/**
- Created by 敲代码的卡卡罗特
- on 2018/11/1 22:04.
*/
public interface IBaseMapper<T> extends Mapper<T>, MySqlMapper<T> {
}
就ok了。