Spring Boot整合mybatis
作者:互联网
Spring Boot整合mybatis
我使用的是druid数据库连接池
1、创建maven项目
1.1、创建主程序类MainApplication.java
@SpringBootApplication
package com.miao;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.context.ConfigurableApplicationContext;
/**
* 主程序类
* @SpringBootApplication :这是一个SpringBoot应用
*
*/
@SpringBootApplication
public class MainApplication {
public static void main(String[] args) {
ConfigurableApplicationContext run = SpringApplication.run(MainApplication.class, args);
//run.getBean("");
}
}
1.2、创建相关文件
- application.xml(或者application.properties)
- java文件夹下创建所需包bean、service、controller、mapper,config
- resource文件夹下创建mybatis文件夹用来存放mybatis配置文件和mapper映射文件
- mabatis文件夹下创建mybatis-config.xml(mybatis核心配置文件),和mapper文件夹(用来存放mapper映射文件)
1.3、项目架构图
2、pom.xml导入所需依赖
web、jdbc、mysql驱动、druid、mybatis
<?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>org.miao</groupId>
<artifactId>SpringBoot</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.8.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.49</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.17</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.4</version>
</dependency>
</dependencies>
</project>
3、application.yaml配置相关数据
spring:
datasource:
url: jdbc:mysql://localhost:3306/market
password: 123456
driver-class-name: com.mysql.jdbc.Driver
username: root
druid:
aop-patterns: com.atguigu.admin.* #监控SpringBean
filters: stat,wall # 底层开启功能,stat(sql监控),wall(防火墙)
stat-view-servlet: # 配置监控页功能
enabled: true
login-username: admin
login-password: admin
resetEnable: false
web-stat-filter: # 监控web
enabled: true
urlPattern: /*
exclusions: '*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*'
filter:
stat: # 对上面filters里面的stat的详细配置
slow-sql-millis: 1000
logSlowSql: true
enabled: true
wall:
enabled: true
config:
drop-table-allow: false
mybatis:
config-location: classpath:mybatis/mybatis-config.xml #全局配置文件位置
mapper-locations: classpath:mybatis/mapper/*.xml #sql映射文件位置
4、mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- <environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>-->
<!-- <mappers>
<mapper resource="org/mybatis/example/BlogMapper.xml"/>
</mappers>-->
</configuration>
5、bean包下创建User.java
我要查询的表 变量一定要对应好表
user.java
谨记:添加注解@Component
import org.springframework.stereotype.Component;
@Component
public class User {
private int uid;
private String uname;
private String sex;
private String upass;
public User(){
}
public User(int uid, String uname, String sex, String upass) {
this.uid = uid;
this.uname = uname;
this.sex = sex;
this.upass = upass;
}
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getUpass() {
return upass;
}
public void setUpass(String upass) {
this.upass = upass;
}
@Override
public String toString() {
return "User{" +
"uid=" + uid +
", uname='" + uname + '\'' +
", sex='" + sex + '\'' +
", upass='" + upass + '\'' +
'}';
}
}
6、 mapper包里面创建接口UserMapper.java
谨记:添加注解@Mapper
package com.miao.mapper;
import com.miao.bean.User;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface UserMapper {
public User getById(Integer id);
}
7、mybatis包下的mapper包下创建UserMapper.xml
注意:mapper的namespace千万别写错
这个里面可能犯错的地方很多一定要多注意
<?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.miao.mapper.UserMapper">
<!-- public User getById(Integer id);-->
<select id="getById" resultType="com.miao.bean.User">
select * from users where uid = #{id}
</select>
</mapper>
8、 service包下创建UserService.java(也可以分成接口和实现类我就方便着写了)
@Service
public class UserService {
@Autowired
UserMapper usermapper;
public User getById(Integer id){
User user = usermapper.getById(id);
return user;
}
}
9、controller包下创建Usercontroller.java
@RestController
public class Usercontroller{
@Autowired
UserService userService;
@GetMapping("/user")
public Map<String,Object> fun01(@RequestParam("id") Integer id){
Map<String,Object> map = new HashMap<>();
User user = userService.getById(id);
map.put("user",user);
return map;
}
}
10、启动项目
访问http://localhost:8080/user?id=101
成功
总算成功了,中间出了好多问题
11、注意点
(操作的表不同类名也各不相同,我以我的为准说一下注意点)
- application配置文件(spring核心配置文件)里面mybatis配置文件的位置是否正确(这个地方idea是无法智能识别的,拼错了也不会报红要注意)
- bean包下的User.java、Service包下的UserService.java、controller·包下的Usercontroller.java是否加入容器否则会找不到组件
- bean包下的User.java里面的变量是否与数据库相照应
- bean包下的User.java是否有set、get等各种方法
- mapper包下的User.java接口是否添加注解@Mapper
- UserMapper.xml里面的namespace是否正确(指向UserMapper.java)
- UserMapper.xml里面的sql语句是否正确
标签:java,String,包下,Spring,Boot,User,mybatis,public 来源: https://blog.csdn.net/qq_45566354/article/details/113188671