[Java知识库] Spring boot中使用线程池如何控制主线程和子线程的事务

@Service
public class PersonServiceImpl extends ServiceImpl<PersonMapper, Person> implements IPersonService {

    @Autowired
    private SqlSessionTemplate sqlSessionTemplate;

    @Autowired
    private SchoolMapper schoolMapper;

    private ArrayBlockingQueue queue=new ArrayBlockingQueue(8,true);

    private ThreadPoolExecutor.CallerRunsPolicy policy=new ThreadPoolExecutor.CallerRunsPolicy();

    //1、创建核心线程为10的线程池
    private ThreadPoolExecutor executor = new ThreadPoolExecutor(10,15,10, TimeUnit.SECONDS
            ,queue,policy);


    @Override
    public int insertPerson(Person person) {
        return this.baseMapper.insert(person);
    }

    @Override
    @Transactional
    public void inserPersonBatch(List<Person> list) throws SQLException {

        //2、根据sqlSessionTemplate获取SqlSession工厂
        SqlSessionFactory sqlSessionFactory = sqlSessionTemplate.getSqlSessionFactory();
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //3、获取Connection来手动控制事务
        Connection connection = sqlSession.getConnection();
        try{
            //4、设置手动提交
            connection.setAutoCommit(false);
            //5、获取PersonMapper（此处是由于无法通过this.baseMapper调用自定义的saveBatch方法）
            PersonMapper mapper = sqlSession.getMapper(PersonMapper.class);
            //6、主线程去删除t_school表中id为1的数据
            schoolMapper.deleteById("1");
            //7、将传入List中的10000个数据按1000一组均分成10组
            List<List<Person>> lists = ListUtils.averageAssign(list,1000);
            //8、新建任务列表
            List<Callable<Integer>> callableList = new ArrayList<>();
            //9、根据均分的5组数据分别新建5个Callable任务
            for(int i = 0; i < lists.size(); i++){
                List<Person> insertList = lists.get(i);
                Callable<Integer> callable = new Callable<Integer>() {
                    @Override
                    public Integer call() throws Exception {
                        int n = 0;
                        try{
                            n = mapper.saveBatch(insertList);
                        }catch (Exception e){
                            //插入失败返回0
                            return n;
                        }
                        //插入成功返回成功提交数
                        return n;
                    }
                };
                callableList.add(callable);
            }

            //10、任务放入线程池开始执行
            List<Future<Integer>> futures = executor.invokeAll(callableList);
            //11、对比每个任务的返回值 <= 0 代表执行失败
            for(Future<Integer> future : futures){
                if(future.get() <= 0){
                    //12、只要有一组任务失败回滚整个connection
                    connection.rollback();
                    return;
                }
            }
            //13、主线程和子线程都执行成功 直接提交
            connection.commit();
            System.out.println("添加成功！");

        }catch (Exception e){
            //14、主线程报错回滚
            connection.rollback();
            log.error(e.toString());
            throw new SQLException("出现异常！");
        }
        return;
    }


}

2、PersonMapper中自定义批量插入

    <insert id="saveBatch" parameterType="list">
        insert into t_person(id,name,age,addr,classes,school_id)
        values
            <foreach collection="list" index="index" item="item" separator=",">
                (
                 #{item.id},
                #{item.name},
                #{item.age},
                #{item.addr},
                #{item.classes},
                #{item.schoolId}
                )
            </foreach>
    </insert>

3、均分List工具类

public class ListUtils {

    public static <T> List<List<T>> averageAssign(List<T> source, int limit) {
        if (null == source || source.isEmpty()) {
            return Collections.emptyList();
        }
        List<List<T>> result = new ArrayList<>();
        int listCount = (source.size() - 1) / limit + 1;
        int remaider = source.size() % listCount; // (先计算出余数)
        int number = source.size() / listCount; // 然后是商
        int offset = 0;// 偏移量
        for (int i = 0; i < listCount; i++) {
            List<T> value;
            if (remaider > 0) {
                value = source.subList(i * number + offset, (i + 1) * number + offset + 1);
                remaider--;
                offset++;
            } else {
                value = source.subList(i * number + offset, (i + 1) * number + offset);
            }
            result.add(value);
        }
        return result;
    }


}

四、测试验证：

controller层如下：传入10000条数据

    @GetMapping("/addBatch")
    public void addBatch() {
        List<Person> list = new ArrayList<>();
        for(int i = 1; i <= 10000; i++){
            Person p = new Person();
            p.setId(i);
            p.setName("张三" + i);
            p.setAge(i);
            p.setAddr("重庆");
            p.setClasses("一班");
            p.setSchoolId(i);
            list.add(p);
        }
        try{
            this.iPersonService.inserPersonBatch(list);
        }catch (Exception e){
            e.printStackTrace();
        }
    }