异常 002 出现异常:connection closed，大佬们求教，是不是多线程影响到了，下面是方法

@Resource private SqlSessionTemplate sqlSessionTemplate;

public void threadInsert(List<StudentVO> studentVOList) throws SQLException {
    long start = System.currentTimeMillis();
    Connection connection = sqlSessionTemplate.getConnection();
    CacheTestMapper cacheTestMapper
            = sqlSessionTemplate
            .getSqlSessionFactory()
            .openSession()
            .getMapper(CacheTestMapper.class);
    try {
        //设置手动提交
        connection.setAutoCommit(false);
        //先删除数据
        cacheTestMapper.deleteStudentById(1L);
        //获取线程池
        ExecutorService executorService = ExecutorUtil.getThreadPool();
        //拆分数据创建任务
        List<List<StudentVO>> lists = this.averageAssign(studentVOList, 5);
        Thread[] threads = new Thread[lists.size()];
        //监控子线程执行完毕,再执行主线程,要不然会导致主线程关闭,子线程也会随着关闭
        CountDownLatch countDownLatch = new CountDownLatch(lists.size());
        for (int i = 0; i < lists.size(); i++) {
            List<StudentVO> list = lists.get(i);
            threads[i] = new Thread(() -> {
                try {
                    //批量添加,mybatisPlus 中自带的 batch 方法
                    cacheTestMapper.batchInsert(list);
                } finally {
                    countDownLatch.countDown();
                }
            });
        }
        for (int i = 0; i < lists.size(); i++) {
            executorService.execute(threads[i]);
        }
        //当子线程执行完毕时,主线程再往下执行
        countDownLatch.await();
        System.out.println("添加完毕");
        connection.commit();
        long end = System.currentTimeMillis();
        System.out.println("多线程耗时：" + (end - start));
    } catch (Exception e) {
        connection.rollback();
        throw new RuntimeException("002 出现异常:" + e.getMessage());
    } finally {
        connection.close();
    }
}

bocharud

323 天前

如 #5 和 #7 说的那样, cacheTestMapper 变量内部的 connection 没有被带到子线程中去.

没用过 mybatis, 不过按照你的代码来看, 你前面先拿出一个 connection 调用 setAutoCommit(false). 是否可以说明 mapper 和内部的 conn 和你这个 conn 相等. 那么可以认为它在类似于 thread_local 里面.

如果真是这样, 那么子线程的 mapper 获取不到 conn, 所以它说 connection closed