SpringBoot整合MyBatis逆向工程及 MyBatis通用Mapper实例详解

Z时代
2024-01-10
分类：IT

一、添加所需依赖，当前完整的pom文件如下：


<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>
 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>1.5.6.RELEASE</version>
 </parent>
 <groupId>org.rcddup</groupId>
 <artifactId>rcddup-custom</artifactId>
 <version>1.0.0</version>
 <properties>
  <java.version>1.8</java.version>
  <mybatis.version>1.3.1</mybatis.version>
  <mapper.version>3.4.3</mapper.version>
  <mybatis-generator.version>1.3.3</mybatis-generator.version>
  <mybatis-tk.version>1.1.4</mybatis-tk.version>
  <pagehelper.version>1.2.1</pagehelper.version>
 </properties>
 <dependencies>
  <!-- SpringBoot - Web -->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <!-- SpringBoot - MyBatis -->
  <dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>${mybatis.version}</version>
  </dependency>
  <!-- SpringBoot - MyBatis 逆向工程 -->
  <dependency>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-core</artifactId>
   <version>${mybatis-generator.version}</version>
  </dependency>
  <!-- MyBatis 通用 Mapper -->
  <dependency>
   <groupId>tk.mybatis</groupId>
   <artifactId>mapper-spring-boot-starter</artifactId>
   <version>${mybatis-tk.version}</version>
  </dependency>
  <!-- Mysql -->
  <dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
  </dependency>
 </dependencies>
 <build>
  <plugins>
   <!-- MyBatis 逆向工程 插件 -->
   <plugin>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-maven-plugin</artifactId>
    <version>${mybatis.generator.version}</version>
    <dependencies>
     <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>${mysql.version}</version>
     </dependency>
     <dependency>
      <groupId>tk.mybatis</groupId>
      <artifactId>mapper</artifactId>
      <version>${mapper.version}</version>
     </dependency>
    </dependencies>
    <configuration>
     <!-- 允许移动生成的文件 -->
     <verbose>true</verbose>
     <!-- 是否覆盖 -->
     <overwrite>true</overwrite>
     <!-- 配置文件 -->
     <configurationFile>
      ${basedir}/src/main/resources/generator/generatorConfig.xml
     </configurationFile>
    </configuration>
   </plugin>
  </plugins>
 </build>
</project>

　　MyBtais 结合通用 Mapper 非常好使，接下来看逆向工程的配置。

　　有关通用Mapper的信息，请查看：https://github.com/abel533/Mapper

二、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>
 <!-- 引入 application.properties -->
 <properties resource="application.properties" />
 <!-- MyBatis3Simple：不生成 Example相关类及方法 -->
 <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
  <property name="beginningDelimiter" value="`" />
  <property name="endingDelimiter" value="`" />
  <!-- 指定生成 Mapper 的继承模板 -->
  <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
   <property name="mappers" value="${generator.mappers}" />
  </plugin>
  <!-- 生成 JavaBean 对象重写 toString方法 -->
  <plugin type="org.mybatis.generator.plugins.ToStringPlugin" />
  <!-- 生成 JavaBean 对象继承 Serializable 类 -->
  <plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
  <!-- 生成 JavaBean 对象重写 equals 和 hashCode 方法 -->
  <!-- <plugin type="org.mybatis.generator.plugins.EqualsHashCodePlugin" /> -->
  <!-- jdbc 连接配置 -->
  <jdbcConnection driverClass="${spring.datasource.driver-class-name}"
   connectionURL="${spring.datasource.url}"
   userId="${spring.datasource.username}"
   password="${spring.datasource.password}">
  </jdbcConnection>
  <javaModelGenerator targetPackage="${generator.javaModel-targetPackage}"
   targetProject="${generator.targetProject}" />
  <sqlMapGenerator targetPackage="${generator.sqlMap-targetPackage}" 
   targetProject="${generator.targetProject}" />
  <javaClientGenerator targetPackage="${generator.javaClient-targetPackage}"
   targetProject="${generator.targetProject}" type="XMLMAPPER" />
  <!-- Mysql 配置 -->
  <!-- <generatedKey column="id" sqlStatement="Mysql" identity="true" /> -->
  <!-- Oracle 配置 -->
  <!-- <generatedKey column="id" sqlStatement="select SEQ_{1}.nextval from dual" identity="false" type="pre"/> -->
  <!-- tableName：数据库表名，domainObjectName：生成文件名 ，schema：数据源-->
  <table tableName="user">
   <generatedKey column="id" sqlStatement="Mysql" identity="true" />
  </table>
 </context>
</generatorConfiguration>

　　我们将对应的信息都在 application.properties 中定义好，在这直接使用，application.properties如下：

# Generator

generator.targetProject=src/main/java

generator.mappers=org.rcddup.app.common.base.IBaseMapper

generator.javaModel-targetPackage=org.rcddup.app.domain

generator.sqlMap-targetPackage=org.rcddup.app.dao

generator.javaClient-targetPackage=org.rcddup.app.dao

三、编写生成Mapper的集成接口IBaseMapper


package org.rcddup.app.common.base;
import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;
public interface IBaseMapper<T> extends Mapper<T>, MySqlMapper<T> {
}

　　集成的 Mapper 以及 MySqlMapper 几乎包含了你所有的 CRUD方法。

四、使用逆向工程生成我们的第一个文件

　　右键项目 --> Maven --> Maven build --> Goals: mybtais-generator:generate，点击 run.....

　　我们的UserMapper以及UserMapper.xml就生成了。

　　（1）UserMapper.java


package org.rcddup.app.dao;
import org.rcddup.app.common.base.IBaseMapper;
import org.rcddup.app.domain.User;
public interface UserMapper extends IBaseMapper<User> {
}

　　（2）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="org.rcddup.app.dao.UserMapper">
 <resultMap id="BaseResultMap" type="org.rcddup.app.domain.User">
 <!--
  WARNING - @mbg.generated
 -->
 <id column="id" jdbcType="BIGINT" property="id" />
 <result column="name" jdbcType="VARCHAR" property="name" />
 <result column="age" jdbcType="TINYINT" property="age" />
 <result column="status" jdbcType="TINYINT" property="status" />
 </resultMap>
</mapper>

　　是不是发现xml中都没有配置任何CRUD方法。

五、重新编写 UserService.java

　　我们原先编写的 UserService 现在我们用新生成的 UserMapper 来重新编写。


package org.rcddup.app.service.impl;
import java.util.List;
import org.rcddup.app.dao.UserMapper;
import org.rcddup.app.domain.User;
import org.rcddup.app.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import tk.mybatis.mapper.entity.Example;
@Service
public class UserService implements IUserService{
 @Autowired
 private UserMapper userMapper;
 @Override
 public List<User> listUser() {
  return userMapper.selectAll();
 }
 @Override
 public User getUserById(Long id) {
  // 方法一：适用于任何字段的查询
//  Example example = new Example(User.class);
//  example.createCriteria().andEqualTo("id", id);
//  List<User> list = userMapper.selectByExample(example);
//  if (list != null && list.size() > 0) {
//   return list.get(0);
//  } else {
//   return null;
//  }
  // 方法二：只适用于主键字段
  return userMapper.selectByPrimaryKey(id);
 }
}