Hi, friends.
I am using HttpClient for a few tests. And I use the below code to run without
success. But the process never stoped.
I use jstack for this and found it always wait for something. Could you help me
please ? Thanks.
parking to wait for <0x000000076c1d0980> (a
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
Best
Minglei
public class HttpClientWithSync {
public static void main(String[] args) {
String url = "https://www.baidu.com/";;
String[] strs = new String[] {url, url, url};
CloseableHttpClient httpclient = HttpClients.createDefault();
for (int i = 0; i < 3; i++) {
HttpGet httpget = new HttpGet(strs[i]);
System.out.println();
try {
System.out.println("Waiting for the contents, hurry! hurry !
hurry!.....");
// take a while and block the main thread.
HttpResponse response = httpclient.execute(httpget);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
System.out.println("============ Get the entity ============ "+
response.getEntity());
}
// after getting the value from the url and then do this or do not
if something unexpected to happen.
System.out.println("Do some other stuff");
} catch (IOException e) {
e.printStackTrace();
}
}
try {
httpclient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
The full thread dump are
2018-06-08 11:02:08
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.161-b12 mixed mode):
"Attach Listener" #12 daemon prio=9 os_prio=31 tid=0x00007fce8904a000
nid=0x1207 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Service Thread" #10 daemon prio=9 os_prio=31 tid=0x00007fce8c04b800 nid=0x5503
runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C1 CompilerThread3" #9 daemon prio=9 os_prio=31 tid=0x00007fce8c002800
nid=0x5303 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread2" #8 daemon prio=9 os_prio=31 tid=0x00007fce89084000
nid=0x5103 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread1" #7 daemon prio=9 os_prio=31 tid=0x00007fce8c002000
nid=0x4f03 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread0" #6 daemon prio=9 os_prio=31 tid=0x00007fce8c001000
nid=0x4d03 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Monitor Ctrl-Break" #5 daemon prio=5 os_prio=31 tid=0x00007fce8a83b800
nid=0x4b03 runnable [0x0000700007e38000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:171)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
- locked <0x000000076adce880> (a java.io.InputStreamReader)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.readLine(BufferedReader.java:324)
- locked <0x000000076adce880> (a java.io.InputStreamReader)
at java.io.BufferedReader.readLine(BufferedReader.java:389)
at com.intellij.rt.execution.application.AppMainV2$1.run(AppMainV2.java:64)
"Signal Dispatcher" #4 daemon prio=9 os_prio=31 tid=0x00007fce8881c000
nid=0x4903 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Finalizer" #3 daemon prio=8 os_prio=31 tid=0x00007fce89003800 nid=0x3903 in
Object.wait() [0x0000700007c32000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x000000076ab08ec0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
- locked <0x000000076ab08ec0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164)
at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209)
"Reference Handler" #2 daemon prio=10 os_prio=31 tid=0x00007fce8b004000
nid=0x3703 in Object.wait() [0x0000700007b2f000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x000000076ab06b68> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Object.java:502)
at java.lang.ref.Reference.tryHandlePending(Reference.java:191)
- locked <0x000000076ab06b68> (a java.lang.ref.Reference$Lock)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)
"main" #1 prio=5 os_prio=31 tid=0x00007fce8a008000 nid=0x1c03 waiting on
condition [0x0000700007110000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x000000076c1d0980> (a
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at
org.apache.http.pool.AbstractConnPool.getPoolEntryBlocking(AbstractConnPool.java:377)
at org.apache.http.pool.AbstractConnPool.access$200(AbstractConnPool.java:67)
at org.apache.http.pool.AbstractConnPool$2.get(AbstractConnPool.java:243)
- locked <0x000000076d160008> (a org.apache.http.pool.AbstractConnPool$2)
at org.apache.http.pool.AbstractConnPool$2.get(AbstractConnPool.java:191)
at
org.apache.http.impl.conn.PoolingHttpClientConnectionManager.leaseConnection(PoolingHttpClientConnectionManager.java:282)
at
org.apache.http.impl.conn.PoolingHttpClientConnectionManager$1.get(PoolingHttpClientConnectionManager.java:269)
at
org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:191)
at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:185)
at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:111)
at
org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
at
org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
at
org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:108)
at
org.apache.flink.streaming.connectors.fs.HttpClientWithSync.main(HttpClientWithSync.java:37)
"VM Thread" os_prio=31 tid=0x00007fce88819000 nid=0x3503 runnable
"GC task thread#0 (ParallelGC)" os_prio=31 tid=0x00007fce8a014000 nid=0x2503
runnable
"GC task thread#1 (ParallelGC)" os_prio=31 tid=0x00007fce8a014800 nid=0x2703
runnable
"GC task thread#2 (ParallelGC)" os_prio=31 tid=0x00007fce89004800 nid=0x2903
runnable
"GC task thread#3 (ParallelGC)" os_prio=31 tid=0x00007fce88800800 nid=0x2b03
runnable
"GC task thread#4 (ParallelGC)" os_prio=31 tid=0x00007fce88808800 nid=0x2d03
runnable
"GC task thread#5 (ParallelGC)" os_prio=31 tid=0x00007fce88809000 nid=0x2f03
runnable
"GC task thread#6 (ParallelGC)" os_prio=31 tid=0x00007fce89005800 nid=0x3103
runnable
"GC task thread#7 (ParallelGC)" os_prio=31 tid=0x00007fce89006000 nid=0x3303
runnable
"VM Periodic Task Thread" os_prio=31 tid=0x00007fce888c7000 nid=0x5703 waiting
on condition
JNI global references: 364
