简介
MyBatis 是一款优秀的持久层框架,它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息,将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。
MyBatis Generator 是一款MyBatis 的代码生成器插件,可以根据数据库表字段自动生成对应的pojo类、mapper.xml文件、dao接口。自动生成的mapper.xml文件有常用的sql语句,能省去我们一大堆工作量。
引入依赖
Spring Boot集成Mybatis需要引入以下依赖:
<!--spring boot与mybatis的整合-->
<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>
引入generator插件
在maven的plugins节点下引入该generator的插件:
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.5</version>
<dependencies>
<dependency>
<groupId> mysql</groupId>
<artifactId> mysql-connector-java</artifactId>
<version> 5.1.39</version>
</dependency>
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.5</version>
</dependency>
</dependencies>
<executions>
<execution>
<id>Generate MyBatis Artifacts</id>
<phase>package</phase>
<goals>
<goal>generate</goal>
</goals>
</execution>
</executions>
<configuration>
<!--允许移动生成的文件 -->
<verbose>true</verbose>
<!-- 是否覆盖 -->
<overwrite>true</overwrite>
<!-- 自动生成的配置 -->
<configurationFile>
src/main/resources/mybatis-generator.xml</configurationFile>
</configuration>
</plugin>
表结构
tbl_user表的结构与数据如下:
基本配置
在application.yml中配置数据库连接信息与mybatis的相关配置:
spring:
datasource: #数据源配置
url: jdbc:mysql://localhost:3306/ssm-crud?characterEncoding=utf-8&useSSL=false
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
type-aliases-package: com.huang.bean #配置pojo类的位置
mapper-locations: classpath:mapper/*.xml #配置mapper.xml的位置
configuration:
map-underscore-to-camel-case: true #开启驼峰命名
generator配置
在src\main\resources下新建mybatis-generator.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>
<context id="DB2Tables" targetRuntime="MyBatis3">
<!--不生成注释-->
<commentGenerator>
<property name="suppressAllComments" value="true" />
</commentGenerator>
<!--配置数据库连接-->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/ssm-crud?useSSL=false"
userId="root"
password="123456">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!--
指定javaBean生成的位置
targetPackage:生成的包的位置
targetProject:生成在哪个工程下
-->
<javaModelGenerator targetPackage="com.huang.bean" targetProject=".\src\main\java">
<property name="enableSubPackages" value="true"/>
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!--指定sql映射文件生成的位置-->
<sqlMapGenerator targetPackage="mapper" targetProject=".\src\main\resources">
<property name="enableSubPackages" value="true"/>
</sqlMapGenerator>
<!--指定dao接口生成的位置-->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.huang.dao" targetProject=".\src\main\java">
<property name="enableSubPackages" value="true"/>
</javaClientGenerator>
<!--
指定每个表的生成策略
tableName:表明
domainObjectName:javabean的类名
-->
<table tableName="tbl_user" domainObjectName="User"/>
</context>
</generatorConfiguration>
执行generator
根据上面再mybatis-generator.xml配置的路径,创建对应的package,双击maven插件执行generator插件:
控制台输出BUILD SUCCESS则证明generator插件运行成功:
[INFO] Scanning for projects...
[INFO]
[INFO] --------------------< com.huang:springbootmybatis >---------------------
[INFO] Building springbootmybatis 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- mybatis-generator-maven-plugin:1.3.5:generate (default-cli) @ springbootmybatis ---
[INFO] Connecting to the Database
[INFO] Introspecting table tbl_user
[INFO] Generating Example class for table tbl_user
[INFO] Generating Record class for table tbl_user
[INFO] Generating Mapper Interface for table tbl_user
[INFO] Generating SQL Map for table tbl_user
[INFO] Saving file UserMapper.xml
[INFO] Saving file UserExample.java
[INFO] Saving file User.java
[INFO] Saving file UserMapper.java
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.926 s
[INFO] Finished at: 2018-11-02T19:55:25+08:00
[INFO] ------------------------------------------------------------------------
执行完generator插件后,会在对应的包生成对应的文件:
编写代码
IUserService.java
public interface IUserService {
User get(Integer id);
}
UserServiceImpl.java
@Service("iUserService")
public class UserServiceImpl implements IUserService {
@Autowired
private UserMapper userMapper;
@Override
public User get(Integer id) {
return userMapper.selectByPrimaryKey(id);
}
}
UserController.java
@RestController
public class UserController {
@Autowired
private IUserService iUserService;
@GetMapping("/get_user/{userId}")
public User getUser(@PathVariable("userId") Integer userId){
User user =iUserService.get(userId);
return user;
}
}
测试
运行项目,访问localhost:8080/get_user/1,浏览器输出信息如下,集成成功: