SpringBoot集成Mybatis 自动生成实体类和Mapper
1.使用IDEA创建一个空的SpringBoot项目
2.在pom.xml中引入以下配置
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<!-- MyBatis 根据实体类自动生成dao层配置-->
<!-- MyBatis Generator -->
<targetJavaProject>${basedir}/src/main/java</targetJavaProject>
<!-- Java接口 -->
<targetMapperPackage>com.jiafly.falsework.dao</targetMapperPackage>
<!-- 实体类 -->
<targetModelPackage>com.jiafly.falsework.entity</targetModelPackage>
<!-- XML生成路径 -->
<targetResourcesProject>${basedir}/src/main/resources</targetResourcesProject>
<targetXMLPackage>mapper</targetXMLPackage>
</properties>
<!-- mybatis 通用mapper配置 -->
<!-- Spring Boot Mybatis 依赖 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>RELEASE</version>
</dependency>
<!-- MySQL 连接驱动依赖 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
<scope>runtime</scope>
</dependency>
<!-- mapper -->
<dependency>
<groupId>tk.mybatis</groupId>
<artifactId>mapper-spring-boot-starter</artifactId>
<version>1.2.3</version>
</dependency>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- mybatis-generator-maven-plugin -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<configurationFile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile>
<overwrite>false</overwrite>
<verbose>true</verbose>
</configuration>
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
3. 在application.yml中配置
spring:
# 数据库相关配置
datasource:
url: jdbc:mysql://localhost:3306/jiafly?useUnicode=true&characterEncoding=UTF-8&useSSL=false&useTimezone=true&serverTimezone=Asia/Shanghai&allowMultiQueries=true
username: root
password: root
driver-class-name: com.mysql.jdbc.Driver
initialSize: 1
minIdle: 1
maxActive: 5
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 180000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
# mybaties 配置
mybatis:
mapperLocations: classpath:mapper/*.xml
typeAliasesPackage: com.jiafly.libra.entity
# 通用mapper 配置 自动生成dao层代码
mapper:
plugin: tk.mybatis.mapper.generator.MapperPlugin
Mapper: tk.mybatis.mapper.common.Mapper
not-empty: false
identity: MYSQL
4. 在src/main/resources文件夹下创建generatorConfig.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<properties resource="application.yml"/>
<context id="Mysql" targetRuntime="MyBatis3" defaultModelType="flat">
<commentGenerator>
<property name="suppressDate" value="true"/>
<property name="suppressAllComments" value="true"/>
</commentGenerator>
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/jiafly"
userId="root"
password="root">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<javaModelGenerator targetPackage="${targetModelPackage}" targetProject="${targetJavaProject}">
<!-- 是否允许子包,即targetPackage.schemaName.tableName -->
<property name="enableSubPackages" value="false"/>
<!-- 是否对model添加 构造函数 -->
<property name="constructorBased" value="true"/>
<!-- 是否对类CHAR类型的列的数据进行trim操作 -->
<property name="trimStrings" value="true"/>
<!-- 建立的Model对象是否 不可改变 即生成的Model对象不会有 setter方法,只有构造方法 -->
<property name="immutable" value="false"/>
</javaModelGenerator>
<sqlMapGenerator targetPackage="${targetXMLPackage}" targetProject="${targetResourcesProject}">
<property name="enableSubPackages" value="false"/>
</sqlMapGenerator>
<javaClientGenerator targetPackage="${targetMapperPackage}" targetProject="${targetJavaProject}" type="XMLMAPPER" >
<property name="enableSubPackages" value="false" />
</javaClientGenerator>
<!-- tableName是数据库的表名,domainObjectName是生成的实体类名称 -->
<table tableName="user_info" domainObjectName="UserInfo" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
</context>
</generatorConfiguration>
5. 执行mybatis-generator-maven-plugin插件
- 执行完毕后会在 com.jiafly.libra.entity中生成实体类,com.jiafly.libra.mapper中生成dao层接口 resources.mapper中生成xml文件。
6. 优化
- 当我们在数据库中增加字段时,需要在对应的实体类中增加字段,xml中也需要去增加字段,去维护,会消耗大量的时间
- 我们可以让接口去继承 Mapper<T> ,删除接口中的所有方法,因为Mapper中都已经实现了。对于的xml中的sql也一并删除,之后增加字段就不需要再去维护
- 优化后的文件如下;
实体类
package com.jiafly.libra.entity;
import java.util.Date;
public class UserInfo {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String userId;
private String mobile;
private String email;
private String openId;
private String unionId;
private String userName;
private String nickName;
private Byte gender;
private Integer age;
private String city;
private String province;
private String country;
private String password;
private Byte vip;
private Byte delFlag;
private Date createTime;
private Date updateTime;
}
接口
package com.jiafly.libra.mapper;
import com.jiafly.libra.entity.UserInfo;
import tk.mybatis.mapper.common.Mapper;
public interface UserInfoMapper extends Mapper<UserInfo> {
}
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="com.jiafly.libra.mapper.UserInfoMapper" >
</mapper>
7.继承Mapper<T>遇到的坑
- 需要在实体的主键上增加@Id注解,否则通用mapper无法识别主键,在是使用mapper的方法做更新查找等操作的时候会带上所有的条件,造成找不到数据。
- 遇到这里问题不会报错,只要注意打印出来的sql语句即可。
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