# mybatis-plus的IService.update修改
# 当前使用版本
V3.4.1
# 该问题是如何引起的？
调用IService接口default boolean update(Wrapper
# 重现步骤
增加以下类：
package com.baomidou.samples.metainfo.service;
import com.baomidou.mybatisplus.extension.service.IService;
import com.baomidou.samples.metainfo.entity.User;
/**
* @Description TODO
* @Author 刘默远
* @Email soul.lau0328@gmail.com
* @Date 2021-01-06 21:10
*/
public interface UserService extends IService<User> {
}
package com.baomidou.samples.metainfo.service.impl;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.baomidou.samples.metainfo.entity.User;
import com.baomidou.samples.metainfo.mapper.UserMapper;
import com.baomidou.samples.metainfo.service.UserService;
import org.springframework.stereotype.Service;
/**
* @Description TODO
* @Author 刘默远
* @Email soul.lau0328@gmail.com
* @Date 2021-01-06 21:12
*/
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
}
package com.baomidou.samples.metainfo;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.samples.metainfo.entity.User;
import com.baomidou.samples.metainfo.mapper.UserMapper;
import com.baomidou.samples.metainfo.service.UserService;
import javax.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
/**
* @Description AutoFillUpdateTest
* @Author 刘默远
* @Email soul.lau0328@gmail.com
* @Date 2021-01-06 21:15
*/
@Slf4j
@RunWith(SpringRunner.class)
@SpringBootTest
public class AutoFillUpdateTest {
@Autowired
private UserService userService;
@Test
public void testUpdate() {
User beforeUser = userService.getById(1L);
log.info("before user:{}", beforeUser);
UpdateWrapper updateWrapper = Wrappers.update();
updateWrapper.set("age",14);
updateWrapper.eq("id",1L);
//此方法有bug。
userService.update(updateWrapper);
log.info("query user:{}", userService.getById(1L));
//以下方法是正确的
userService.update(new User(),updateWrapper);
log.info("query user:{}", userService.getById(1L));
}
}
# 报错信息
2021-01-06 21:18:07.093 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : ==> Preparing: SELECT ID,NAME,AGE,EMAIL,OPERATOR FROM user WHERE ID=?
2021-01-06 21:18:07.122 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : ==> Parameters: 1(Long)
2021-01-06 21:18:07.152 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : <== Total: 1
2021-01-06 21:18:07.153 INFO 33668 --- [ main] c.b.samples.metainfo.AutoFillUpdateTest : before user:User(id=1, name=Jone, age=18, email=test1@baomidou.com, operator=test)
2021-01-06 21:18:07.203 DEBUG 33668 --- [ main] c.b.s.metainfo.mapper.UserMapper.update : ==> Preparing: UPDATE user SET age=? WHERE (id = ?)
2021-01-06 21:18:07.210 DEBUG 33668 --- [ main] c.b.s.metainfo.mapper.UserMapper.update : ==> Parameters: 14(Integer), 1(Long)
2021-01-06 21:18:07.212 DEBUG 33668 --- [ main] c.b.s.metainfo.mapper.UserMapper.update : <== Updates: 1
2021-01-06 21:18:07.212 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : ==> Preparing: SELECT ID,NAME,AGE,EMAIL,OPERATOR FROM user WHERE ID=?
2021-01-06 21:18:07.212 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : ==> Parameters: 1(Long)
2021-01-06 21:18:07.213 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : <== Total: 1
2021-01-06 21:18:07.213 INFO 33668 --- [ main] c.b.samples.metainfo.AutoFillUpdateTest : query user:User(id=1, name=Jone, age=14, email=test1@baomidou.com, operator=test)
//执行userService.update(updateWrapper)后，以上打印信息可看到operator并没有自动填充。
2021-01-06 21:18:07.216 INFO 33668 --- [ main] c.b.s.m.handler.MyMetaObjectHandler : start update fill ....
2021-01-06 21:18:08.729 INFO 33668 --- [ main] c.b.s.m.handler.MyMetaObjectHandler : end update fill!
2021-01-06 21:18:08.729 DEBUG 33668 --- [ main] c.b.s.metainfo.mapper.UserMapper.update : ==> Preparing: UPDATE user SET OPERATOR=?, age=? WHERE (id = ?)
2021-01-06 21:18:08.730 DEBUG 33668 --- [ main] c.b.s.metainfo.mapper.UserMapper.update : ==> Parameters: Soul(String), 14(Integer), 1(Long)
2021-01-06 21:18:08.730 DEBUG 33668 --- [ main] c.b.s.metainfo.mapper.UserMapper.update : <== Updates: 1
2021-01-06 21:18:08.731 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : ==> Preparing: SELECT ID,NAME,AGE,EMAIL,OPERATOR FROM user WHERE ID=?
2021-01-06 21:18:08.731 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : ==> Parameters: 1(Long)
2021-01-06 21:18:08.732 DEBUG 33668 --- [ main] c.b.s.m.mapper.UserMapper.selectById : <== Total: 1
2021-01-06 21:18:08.732 INFO 33668 --- [ main] c.b.samples.metainfo.AutoFillUpdateTest : query user:User(id=1, name=Jone, age=14, email=test1@baomidou.com, operator=Soul)
//执行userService.update(new User(),updateWrapper)后，可看到operator并已经自动填充为Soul。
# 修改建议
IService接口的default boolean update(Wrapper
default boolean update(Wrapper<T> updateWrapper) {
return update(null, updateWrapper);
}
修改为
default boolean update(Wrapper<T> updateWrapper) {
T entity = updateWrapper.getEntity();
if (entity == null) {
try {
entity = this.getEntityClass().newInstance();
} catch (InstantiationException e) {
} catch (IllegalAccessException e) {
}
}
return update(entity, updateWrapper);
}
即可解决以上问题。
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