解决java中mybatis报错：org.apache.ibatis.binding.BindingException：Invalid bound statement (not found)：xx

报错信息：

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): springtransactionaldemo.demo.mapper.UserMapper.selectAll
	at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:235) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:53) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.binding.MapperProxy.lambda$cachedInvoker$0(MapperProxy.java:108) ......

代码如下：

UserController

/** * Created By 李柏霖 * 2024/1/13 23:01 */

package springtransactionaldemo.demo.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import springtransactionaldemo.demo.pojo.User;
import springtransactionaldemo.demo.service.IUserService;

import java.util.List;

@Controller
public class UserController {
    

    @Autowired
    private IUserService userService;

    @GetMapping("/getAllUsers")
    @ResponseBody
    public List<User> getAllUsers() {
    
        List<User> users = userService.selectAllUsers();
        System.out.println(users);
        return users;
    }
}

IUserService

/** * Created By 李柏霖 * 2024/1/13 22:24 */

package springtransactionaldemo.demo.service;


import springtransactionaldemo.demo.pojo.User;

import java.util.List;

public interface IUserService {
    
    List<User> selectAllUsers();
}

IUserServiceImpl

/** * Created By 李柏霖 * 2024/1/13 22:25 */

package springtransactionaldemo.demo.service.Impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import springtransactionaldemo.demo.mapper.UserMapper;
import springtransactionaldemo.demo.pojo.User;
import springtransactionaldemo.demo.service.IUserService;

import java.util.List;

@Service
public class IUserServiceImpl implements IUserService {
    

    @Autowired
    private UserMapper userMapper;


    @Override
    @Transactional
    public List<User> selectAllUsers() {
    
        return userMapper.selectAll();
    }
}

UserMapper

/** * Created By 李柏霖 * 2024/1/13 22:22 */

package springtransactionaldemo.demo.mapper;

import org.apache.ibatis.annotations.Mapper;
import springtransactionaldemo.demo.pojo.User;

import java.util.List;

@Mapper
public interface UserMapper {
    
    List<User> selectAll();
}

UserMapper.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="springtransactionaldemo.demo.mapper.UserMapper">
    <!-- MyBatis 映射文件 -->
    <select id="selectAll" resultType="springtransactionaldemo.demo.pojo.User">
    SELECT * FROM user
</select>
</mapper>

DemoApplication

package springtransactionaldemo.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.transaction.annotation.EnableTransactionManagement;


@SpringBootApplication
@EnableTransactionManagement
@MapperScan("springtransactionaldemo.demo.mapper")
public class DemoApplication {
    

    public static void main(String[] args) {
    
        SpringApplication.run(DemoApplication.class, args);
    }

}

解决办法：

在 application.properties文件中添加以下配置：

mybatis.mapper-locations=classpath:mapper/*.xml 

拓展：

上述代码中即在DemoApplication中添加了@MapperScan注解，又在UserMapper类中添加了@Mapper注解。其实这两个只需要加一个即可。我这边习惯全加了

代码运行展示：