1

下面的方法有 2 个 for 循环。firstloop 迭代 36000 次，inner forloop 迭代 24 次，所以插入记录的总数将是 864000 条。代码执行运行近 3.5 小时并终止。（记录插入失败） 仅进行 Session 关闭和事务提交在外部 for 循环结束之后。执行时发现RAM消耗近6.9GB

@SuppressWarnings("unchecked")


public void createBRResults() {

    List<BusinessRules> businessRuleList = null;
    Organization organization = null;
    Brresults brresults = null;
    Criteria criteria = null;
    Criteria newCriteria = null;
    String brStatus = "Live";
    Date date = new Date();
    Session session = sessionFactory.openSession();
    Transaction transaction = null;
    try {
        if (callInfos == null) {
            callInfos = getEntities(CallInfo.class);
        }
        for (CallInfo callInfo : callInfos) {
            transaction = session.beginTransaction();
            criteria = session.createCriteria(BusinessRules.class);
            criteria.createCriteria("businessGoals").add(
                    Restrictions.eq("category", callInfo.getCategory()));
            businessRuleList = criteria.list();
            organization = callInfo.getOrganization();
            for (BusinessRules businessRule : businessRuleList) {
                brresults = new Brresults();
                brresults.setBusinessRule(businessRule);
                brresults.setCallInfo(callInfo);
                brresults.setCreatedDate(date);
                brresults.setModifiedDate(date);
                brresults.setOrganization(organization);
                brresults.setBrrStatus(brStatus);
                brresults.setBrrValue(Math.random() < 0.5 ? 0 : 1);
                session.save(brresults);
                brresults = null;
            }
            criteria = null;
            organization = null;
            businessRuleList = null;
            session.flush();
            session.clear();
            transaction.commit();
            System.gc();
        }
    } catch (Exception ex) {
        ex.printStackTrace();
    } finally {
        session.close();
    }
}

我附上了最后几行 GC 日志来指示内存分配

17034.595：[Full GC（人体工程学）[Psyounggen：979968K-> 979964K（1862144K）] 2.1041939 secs] [Times: user=8.61 sys=0.00, real=2.11 secs]

17036.699：[Full GC（人体工程学）[Psyounggen：979968K-> 979964K（1862144K）] 1.5930338 secs] [Times: user=9.39 sys=0.00, real=1.59 secs] 17038.292: [Full GC (Ergonomics) [PSYoungGen: 979968K->979964K(1862144K)] [ParOldGen: 5576158K->5676158K(565K1)] >6556122K(7438336K), [元空间: 23195K->23195K(1071104K)], 1.9376959 secs] [Times: user=8.51 sys=0.00, real=1.94 secs]

17040.230：[Full GC（人体工程学）[Psyounggen：979968K-> 830418K（1862144K）] 2.9929302 secs] [Times: user=17.97 sys=0.00, real=3.00 secs]

堆 PSYoungGen 总计 1862144K，已使用 889367K [0x0000000715d80000, 0x00000007bdc80000, 0x00000007c0000000)

eden space 979968K, 90% used [0x0000000715d80000,0x000000074c205e48,0x0000000751a80000) from space 882176K, 0% used [0x0000000787f00000,0x0000000787f00000,0x00000007bdc80000) to space 885760K, 0% used [0x0000000751a80000,0x0000000751a80000,0x0000000787b80000) ParOldGen total 5576192K, used 5576027K [0x00000005c1800000 , 0x0000000715d80000, 0x0000000715d80000) object space 5576192K, 99% used [0x00000005c1800000,0x0000000715d56d38,0x0000000715d80000) Metaspace used 23223K, capacity 23502K, committed 24064K, reserved 1071104K class space used 2443K, capacity 2537K, committed 2560K, reserved 1048576K

但是，如果我关闭会话并为每 24 次迭代再次打开，则记录插入成功，所需时间为 55 分钟。但 RAM 利用率约为 3GB。

为什么垃圾收集没有正常进行？代码中的错误是什么？

4

1 回答 1

4

它Session正在累积对您触摸的所有对象的引用，因为如果您在同一会话中请求两次，它必须返回完全相同的对象。您需要定期关闭它以允许它丢弃其上下文。

于 2016-03-22T06:05:56.687 回答