Amazon S3上传InputStream - 线程挂起

Question

我正在编写一个从Amazon s3存储桶中放入/获取文件的基本方法。 以下是我方法的相关代码。“key”是S3名称，“saveStream”是InputStream

Upload myUpload = transferManager.upload(daqBucketName, key, saveStream, metadata);

try {
    myUpload.waitForCompletion();
    saveStream.close();
    } catch (InterruptedException e) {
        key = null;
        e.printStackTrace();
    } catch (AmazonServiceException e) {
        key = null;
        e.printStackTrace();
} catch (AmazonClientException e) {
    key = null;
        e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}   
finally {
        if (saveStream != null) {
            try {
            saveStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        }
}


return key;

}

流上传成功，但有一个线程阻止程序完成（让程序继续运行）。 出了什么问题？这是jstack转储：

"Attach Listener" daemon prio=10 tid=0x6a403c00 nid=0x2019 runnable [0x00000000]
   java.lang.Thread.State: RUNNABLE

"DestroyJavaVM" prio=10 tid=0xb6609400 nid=0x1b51 waiting on condition [0x00000000]
   java.lang.Thread.State: RUNNABLE

"s3-transfer-manager-worker-1" prio=10 tid=0x695d1800 nid=0x1b5f waiting on condition [0x68efe000]
   java.lang.Thread.State: WAITING (parking)
    at sun.misc.Unsafe.park(Native Method)
    - parking to wait for  <0x9f3a2178> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
    at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2043)
    at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:386)
    at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1043)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1103)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:679)

"java-sdk-http-connection-reaper" daemon prio=10 tid=0x69551800 nid=0x1b5e waiting on condition [0x69292000]
   java.lang.Thread.State: TIMED_WAITING (sleeping)
    at java.lang.Thread.sleep(Native Method)
    at com.amazonaws.http.IdleConnectionReaper.run(IdleConnectionReaper.java:75)

"Low Memory Detector" daemon prio=10 tid=0xb66cb000 nid=0x1b5c runnable [0x00000000]
   java.lang.Thread.State: RUNNABLE

"C2 CompilerThread1" daemon prio=10 tid=0xb66c9400 nid=0x1b5b waiting on condition [0x00000000]
   java.lang.Thread.State: RUNNABLE

"C2 CompilerThread0" daemon prio=10 tid=0xb66c7400 nid=0x1b5a waiting on condition [0x00000000]
   java.lang.Thread.State: RUNNABLE

"Signal Dispatcher" daemon prio=10 tid=0xb66c6000 nid=0x1b59 runnable [0x00000000]
   java.lang.Thread.State: RUNNABLE

"Finalizer" daemon prio=10 tid=0xb66b6400 nid=0x1b58 in Object.wait() [0x6ae7d000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on <0x9f2a02c0> (a java.lang.ref.ReferenceQueue$Lock)
    at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:133)
    - locked <0x9f2a02c0> (a java.lang.ref.ReferenceQueue$Lock)
    at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:149)
    at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:177)

"Reference Handler" daemon prio=10 tid=0xb66b4c00 nid=0x1b57 in Object.wait() [0x6a7eb000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on <0x9f2a4038> (a java.lang.ref.Reference$Lock)
    at java.lang.Object.wait(Object.java:502)
    at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133)
    - locked <0x9f2a4038> (a java.lang.ref.Reference$Lock)

"VM Thread" prio=10 tid=0xb66b1000 nid=0x1b56 runnable 

"GC task thread#0 (ParallelGC)" prio=10 tid=0xb6610800 nid=0x1b52 runnable 

"GC task thread#1 (ParallelGC)" prio=10 tid=0xb6611c00 nid=0x1b53 runnable 

"GC task thread#2 (ParallelGC)" prio=10 tid=0xb6613400 nid=0x1b54 runnable 

"GC task thread#3 (ParallelGC)" prio=10 tid=0xb6614c00 nid=0x1b55 runnable 

"VM Periodic Task Thread" prio=10 tid=0xb66cd400 nid=0x1b5d waiting on condition 

JNI global references: 1641