ALTER TABLE `user`
ADD COLUMN `version`  int UNSIGNED NULL COMMENT '版本信息';

import com.baomidou.mybatisplus.annotation.*;
 
@TableName(value = "user")
public class AnnotationUser5Bean {
   @TableId(value = "user_id", type = IdType.AUTO)
   private String userId;
    
   @TableField("name")
   private String name;
    
   @TableField("sex")
   private String sex;
    
   @TableField("age")
   private Integer age;
    
   @Version
   private int version;
   // 忽略 getter 和 setter 方法
}

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.OptimisticLockerInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
@Configuration
public class MybatisPlusConfig {
 
    @Bean
    public MybatisPlusInterceptor paginationInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        // 樂觀鎖插件
        interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());
        return interceptor;
    }
 
}

package com.hxstrive.mybatis_plus.simple_mapper.annotation;
 
import com.hxstrive.mybatis_plus.mapper.AnnotationUser5Mapper;
import com.hxstrive.mybatis_plus.model.AnnotationUser5Bean;
import org.junit.jupiter.api.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;
import java.util.concurrent.CountDownLatch;
 
@RunWith(SpringRunner.class)
@SpringBootTest
class AnnotationDemo5 {
 
    @Autowired
    private AnnotationUser5Mapper userMapper;
 
    @Test
    void contextLoads() throws Exception {
        // 重置數(shù)據(jù)
        AnnotationUser5Bean user5Bean = new AnnotationUser5Bean();
        user5Bean.setUserId(1);
        user5Bean.setAge(0);
        user5Bean.setVersion(0);
        userMapper.updateById(user5Bean);
 
        // 修改數(shù)據(jù)
        for (int i = 0; i < 10; i++) {
            System.out.println("第 " + (i + 1) + " 次修改數(shù)據(jù)");
            final CountDownLatch countDownLatch = new CountDownLatch(2);
            modifyUser(countDownLatch, "My-Thread-A", 1);
            modifyUser(countDownLatch, "My-Thread-B", 1);
            countDownLatch.await();
            Thread.sleep(100L);
        }
    }
 
    private void modifyUser(final CountDownLatch countDownLatch, String threadName, int userId) {
        Thread t = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    String threadName = Thread.currentThread().getName();
                    try {
                        AnnotationUser5Bean userBean = userMapper.selectById(userId);
                        if (null == userBean) {
                            return;
                        }
                        AnnotationUser5Bean newBean = new AnnotationUser5Bean();
                        newBean.setName(userBean.getName());
                        newBean.setSex(userBean.getSex());
                        newBean.setAge(userBean.getAge() + 1);
                        newBean.setUserId(userBean.getUserId());
                        newBean.setVersion(userBean.getVersion());
                        int result = userMapper.updateById(newBean);
                        System.out.println("result=" + result + " ==> " + userBean);
                    } catch (Exception e) {
                        System.err.println(threadName + " " + e.getMessage());
                    }
                } finally {
                    countDownLatch.countDown();
                }
            }
        });
        t.setName(threadName);
        t.start();
    }
 
}