前言
Hi 我是来自西部大嫖客杰西。
这篇文章主要是讲述如何使用 Spring Boot 结合 MyBatis 实现 CRUD。
搭建步骤
- 初始项目
- 初始数据库
- 导入依赖
application.yml添加上数据库的配置MybatisConfig配置类- 编写操作数据库的
model层类 - 编写操作数据库的
mapper文件及repository层类 - 编写操作数据库的
service层的类 - 编写操作数据库的
controller层的类
初始项目
初始化方法我一般用以下两种
- 通过 start.spring.io 自定义项目，然后下载/导入。
- 通过 IDEA 来新建
Spring Boot项目。
初始数据库
创建一个数据库，库名为 demo001，然后执行以下 SQL
CREATE TABLE "sys_user" (
"userId" bigint(11) NOT NULL AUTO_INCREMENT COMMENT '用户标识',
"username" varchar(50) NOT NULL COMMENT '用户名',
"password" varchar(100) DEFAULT NULL COMMENT '密码',
"state" varchar(50) DEFAULT NULL COMMENT '状态:NORMAL正常 PROHIBIT禁用',
PRIMARY KEY ("userId") USING BTREE,
UNIQUE KEY "username" ("username") USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 COMMENT='用户表';
导入依赖
<!-- mybatis -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.0.0</version>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- lomkok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
<scope>provided</scope>
</dependency>
由于 Mybatis 的 mapper 文件处于 resources 目录下，所以在 Mavan 打包的时候需要扫描 resource 目录。
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<!-- 打包时拷贝MyBatis的映射文件 -->
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.*</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
application.yml 添加上数据库的配置
server:
port: 8080
spring:
datasource:
driverClassName: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://192.168.1.12:3521/demo001?useUnicode=true&zeroDateTimeBehavior=convertToNull&autoReconnect=true&characterEncoding=utf-8
username: root
password: root
MybatisConfig 配置类
在项目目录下创建一个 config 文件夹，新建 MybatisConfig 文件。==记得 MapperScan 注解和 setTypeAliasesPackage 都替换成为自己相应的内容==。
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import javax.sql.DataSource;
@Configuration
@MapperScan("com.jc.demo001.repository") // 扫描 mapper 接口
public class MybatisConfig {
@Autowired
private DataSource dataSource;
@Bean
public SqlSessionFactory sqlSessionFactory() throws Exception {
SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
sessionFactory.setDataSource(dataSource);
sessionFactory.setTypeAliasesPackage("com.jc.**.model"); // 扫描实体类
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
sessionFactory.setMapperLocations(resolver.getResources("classpath*:mapper/*.xml")); // 扫描映射文件
return sessionFactory.getObject();
}
}
编写操作数据库的 model 层类
在项目目录下创建一个 model 文件夹，新建 SysUser.java。
model/SysUser.java
import lombok.Getter;
import lombok.Setter;
@Getter
@Setter
public class SysUser {
private Integer user_id;
private String username;
private String password;
private String salt;
private String state;
}
编写操作数据库的 mapper 文件及 repository 层类
mapper 文件夹下创建一个 repository/SysUserMapper.java
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;
public interface SysUserMapper {
SysUser findUserById(@Param("id") Integer id);
void deleteUserById(@Param("id") String id);
void addUser(@Param("sysUser") SysUser sysUser);}
并在 resources/SysUserMapper.xml，==记得替换里面的 namespace 和 resultType==。
<?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.jc.demo001.repository.SysUserMapper">
<select id="findUserById" resultType="com.jc.demo001.model.SysUser">
select * from sys_user where user_id = #{id}
</select>
<delete id="deleteUserById">
DELETE FROM sys_user where user_id = #{id}
</delete>
<insert id="addUser" parameterType="com.jc.demo001.model.SysUser">
insert info sys_user (username, password, salt, state) values (#{sysUser.username}, #{sysUser.password}, #{sysUser.salt}, #{sysUser.state})
</insert>
</mapper>
编写操作数据库的 service 层的类
我们先增加一个接口 service/SysUserService.java
public interface SysUserService {
SysUser findUserById(String id);
String deleteUserById(String id);
String addUser(SysUser sysUser);
}
然后添加一个实现类 service/impl/SysUserServiceImpl.java
@Service("sysUserService")
public class SysUserServiceImpl implements SysUserService{
@Autowired
private SysUserMapper sysUserMapper;
@Override
public SysUser findUserById(String id) {
SysUser sysUser = sysUserMapper.findUserById(Integer.valueOf(id));
return sysUser;
}
@Override
public String deleteUserById(String id) {
sysUserMapper.deleteUserById(id);
return "success";
}
@Override
public String addUser(SysUser sysUser) {
sysUserMapper.addUser(sysUser);
return "success";
}
}
编写操作数据库的 controller 层的类
添加个 controller
@RestController
@RequestMapping("/user")
public class SysUserController {
@Autowired
private SysUserService sysUserService;
@RequestMapping("/info/{id}")
public SysUser info(@PathVariable("id") String id) {
SysUser sysUser = sysUserService.findUserById(id);
return sysUser;
}
@RequestMapping("/delete/{id}")
public String delete(@PathVariable("id") String id) {
return sysUserService.deleteUserById(id);
}
@RequestMapping("/add/{id}")
public String add(@RequestBody SysUser sysUser) {
return sysUserService.addUser(sysUser);
}
}
测试
浏览器直接输入
