Springboot3.3 + Mybatis / Mybatis-plus
Java17, Springboot 3.3.5, 项目一启动就报错：
Invalid value type for attribute 'factoryBeanObjectType': java.lang.String我知道问题出现在pom依赖的版本上。但网上对于Springboot3.3的配置资料并不多，且在我代码上实测还是会报错。搞了一天终于解决了，希望能对同样问题的人有帮助。
Springboot + Mybatis
项目结构
我的pom文件
依赖配置是成功的一半。。。其中 mybatis-plus-spring-boot3-starter 是最重要的！
<?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 https://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>3.3.5</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>demo</description>
<url/>
<licenses>
<license/>
</licenses>
<developers>
<developer/>
</developers>
<scm>
<connection/>
<developerConnection/>
<tag/>
<url/>
</scm>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- mysql驱动依赖 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
<!-- MyBatisPlus依赖 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-spring-boot3-starter</artifactId>
<version>3.5.5</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
</project>
我的application.properties
spring.application.name=demo
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/数据库名?useSSL=false
spring.datasource.username=root
spring.datasource.password=密码
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
server.port=8080才知道这种格式和下面这种是不通用的..
spring:
application.name:demo
datasource:
driver-class-name:com.mysql.jdbc.Driver
url:jdbc:mysql://localhost:3306/数据库名?useSSL=false
......
我的数据库
navicat里创建表，随便填几个数据
测试一下
配置完这些，可以在测试类里测一下，是否连接成功。这里成功了再接着往下做。
package com.example.demo;
import jakarta.annotation.Resource;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import javax.sql.DataSource;
import java.sql.SQLException;
@SpringBootTest
class DemoApplicationTests {
@Resource
DataSource dataSource;
@Test
void contextLoads() throws SQLException {
System.out.println("获取的数据库连接为:"+ dataSource.getConnection());
}
}
我的entity
@Data
// 这里亲测不需要写表名
public class User {
private int id;
private String name;
public int getId() {
return id;
}
public String getName() {
return name;
}
public void setId(int id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
}
我的Mapper
package com.example.demo.mapper;
import com.example.demo.entity.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.*;
import java.util.List;
@Mapper
public interface UserMapper{
// 在sql语句中指定表名即可
@Select("select * from user0")
List<User> find();
@Select("select * from user0 where id=#{id}")
User selectById(int id);
}
我的Controller
package com.example.demo.controller;
import com.example.demo.mapper.UserMapper;
import com.example.demo.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
public class UserController {
@Autowired
private UserMapper userMapper;
@GetMapping("/user")
public void query(){
List<User> list = userMapper.find();
System.out.println(list);
User user = userMapper.selectById(1);
System.out.println(user);
}
}我的Application
package com.example.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.example.demo.mapper") //不要忘记
public class HelloApplication {
public static void main(String[] args) {
SpringApplication.run(HelloApplication.class, args);
}
}
OK，可以运行Application了！结果如下：
Springboot + Mybatis-plus
pom，properties配置，数据库都不用改动。
改动1：entity
如果你的表名和类名不同（不区分大小写），比如我的表名是user0，类名为User。那么需要新增注解。
@Data
@TableName("user0")
public class User {
private int id;
private String name;
......
}改动2：Mapper
继承BaseMapper以后，不需要我们再去定义方法了，只需要调用BaseMapper里的方法即可。
@Mapper
public interface UserMapper extends BaseMapper<User>{
// 空
}改动3：Controller
@RestController
public class UserController {
@Autowired
private UserMapper userMapper;
@GetMapping("/user")
public void query(){
// 查询，selectList括号内写条件
List<User> list = userMapper.selectList(null);
System.out.println(list);
// 条件查询
QueryWrapper queryWrapper = new QueryWrapper();
queryWrapper.eq("name","zhangsan");
List<User> user = userMapper.selectList(queryWrapper);
System.out.println(user);
}
}再次运行Application即可成功。