我有一个 SwingWorker 后台线程，其中包含以下代码来执行请求并解析响应:
(new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() {
...
HttpRequest listRequest = HttpRequest
.newBuilder(url)
.GET()
.build();
HttpResponse<String> listResponse = client
.send(listRequest, HttpResponse.BodyHandlers.ofString());
/* listResponse.body() is correct and can be printed/logged */
JSONObject listing = new JSONObject(listResponse.body()); /* hangs when run from JAR */
...
return null;
}
}).execute();
org.json的版本是20190722(我也尝试过20800813)，JVM是Oracle HotSpot 12.0.1 2019-04-16(build 12.0.1+12)
maven编译器源和目标在POM中设置为9。 (以及 Eclipse 中的 Java-SE9。)
当我从 eclipse 运行代码时，它使用以下命令直接从目标类启动它:
/Library/Java/JavaVirtualMachines/jdk-12.0.1.jdk/Contents/Home/bin/java \
-Dfile.encoding=UTF-8 \
-classpath \
/Users/example/workspace/upload-client/target/classes:\
/Users/example/.m2/repository/org/projectlombok/lombok/1.18.10/lombok-1.18.10.jar:\
/Users/example/.m2/repository/org/json/json/20190722/json-20190722.jar \
com.example.UploadClient
一切都很好，但是当我使用这个稍微修改过的命令从 JAR 加载它时:
/Library/Java/JavaVirtualMachines/jdk-12.0.1.jdk/Contents/Home/bin/java \
-Dfile.encoding=UTF-8 \
-jar ./target/upload-client-1.0.jar \
com.example.UploadClient
它卡在JSONObjectListing = new JSONObject(listResponse.body());行上。我已在该行周围插入了日志记录，以确定 listResponse.body() 是否按预期返回 5k 的正确 json 字符串。
从 jar 运行时，执行会在此行停止并且不会恢复。这里列出了 Jstack 输出:
2019-10-22 13:37:55
Full thread dump Java HotSpot(TM) 64-Bit Server VM (12.0.1+12 mixed mode, sharing):
Threads class SMR info:
_java_thread_list=0x00007f9ac10242d0, length=18, elements={
0x00007f9ac0819000, 0x00007f9ac081c000, 0x00007f9ac0805800, 0x00007f9ac1803000,
0x00007f9ac1804800, 0x00007f9ac1808000, 0x00007f9ac1821000, 0x00007f9ac088f000,
0x00007f9ac010a000, 0x00007f9ac010c000, 0x00007f9abfa00800, 0x00007f9ac2011800,
0x00007f9ac0187000, 0x00007f9ac01b1000, 0x00007f9abfc2f000, 0x00007f9ac02f3800,
0x00007f9ac00da800, 0x00007f9ac19ce000
}
"Reference Handler" #2 daemon prio=10 os_prio=31 cpu=0.62ms elapsed=127.37s tid=0x00007f9ac0819000 nid=0x3a03 waiting on condition [0x000070000d2d1000]
java.lang.Thread.State: RUNNABLE
at java.lang.ref.Reference.waitForReferencePendingList(java.base@12.0.1/Native Method)
at java.lang.ref.Reference.processPendingReferences(java.base@12.0.1/Reference.java:241)
at java.lang.ref.Reference$ReferenceHandler.run(java.base@12.0.1/Reference.java:213)
"Finalizer" #3 daemon prio=8 os_prio=31 cpu=1.05ms elapsed=127.37s tid=0x00007f9ac081c000 nid=0x4903 in Object.wait() [0x000070000d3d4000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@12.0.1/Native Method)
- waiting on <no object reference available>
at java.lang.ref.ReferenceQueue.remove(java.base@12.0.1/ReferenceQueue.java:155)
- locked <0x000000070055f0b0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(java.base@12.0.1/ReferenceQueue.java:176)
at java.lang.ref.Finalizer$FinalizerThread.run(java.base@12.0.1/Finalizer.java:170)
"Signal Dispatcher" #4 daemon prio=9 os_prio=31 cpu=0.26ms elapsed=127.36s tid=0x00007f9ac0805800 nid=0x3d07 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread0" #5 daemon prio=9 os_prio=31 cpu=1884.06ms elapsed=127.36s tid=0x00007f9ac1803000 nid=0x5603 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
No compile task
"C1 CompilerThread0" #8 daemon prio=9 os_prio=31 cpu=1066.76ms elapsed=127.36s tid=0x00007f9ac1804800 nid=0x5803 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
No compile task
"Sweeper thread" #9 daemon prio=9 os_prio=31 cpu=11.33ms elapsed=127.36s tid=0x00007f9ac1808000 nid=0xa603 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Service Thread" #10 daemon prio=9 os_prio=31 cpu=0.07ms elapsed=127.34s tid=0x00007f9ac1821000 nid=0x5a03 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Common-Cleaner" #11 daemon prio=8 os_prio=31 cpu=1.22ms elapsed=127.34s tid=0x00007f9ac088f000 nid=0xa303 in Object.wait() [0x000070000dae9000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(java.base@12.0.1/Native Method)
- waiting on <no object reference available>
at java.lang.ref.ReferenceQueue.remove(java.base@12.0.1/ReferenceQueue.java:155)
- locked <0x000000070057a0f8> (a java.lang.ref.ReferenceQueue$Lock)
at jdk.internal.ref.CleanerImpl.run(java.base@12.0.1/CleanerImpl.java:148)
at java.lang.Thread.run(java.base@12.0.1/Thread.java:835)
at jdk.internal.misc.InnocuousThread.run(java.base@12.0.1/InnocuousThread.java:134)
"AppKit Thread" #12 daemon prio=5 os_prio=31 cpu=3875.45ms elapsed=127.25s tid=0x00007f9ac010a000 nid=0x307 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"AWT-Shutdown" #13 prio=5 os_prio=31 cpu=0.19ms elapsed=127.22s tid=0x00007f9ac010c000 nid=0x8c03 in Object.wait() [0x000070000dc6f000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@12.0.1/Native Method)
- waiting on <no object reference available>
at java.lang.Object.wait(java.base@12.0.1/Object.java:326)
at sun.awt.AWTAutoShutdown.run(java.desktop@12.0.1/AWTAutoShutdown.java:291)
- locked <0x000000070055f0f0> (a java.lang.Object)
at java.lang.Thread.run(java.base@12.0.1/Thread.java:835)
"AWT-EventQueue-0" #14 prio=6 os_prio=31 cpu=2127.72ms elapsed=126.82s tid=0x00007f9abfa00800 nid=0xd003 waiting on condition [0x000070000e001000]
java.lang.Thread.State: WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@12.0.1/Native Method)
- parking to wait for <0x000000070058ae30> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(java.base@12.0.1/LockSupport.java:194)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(java.base@12.0.1/AbstractQueuedSynchronizer.java:2081)
at java.awt.EventQueue.getNextEvent(java.desktop@12.0.1/EventQueue.java:566)
at java.awt.EventDispatchThread.pumpOneEventForFilters(java.desktop@12.0.1/EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEventsForFilter(java.desktop@12.0.1/EventDispatchThread.java:124)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(java.desktop@12.0.1/EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(java.desktop@12.0.1/EventDispatchThread.java:109)
at java.awt.EventDispatchThread.pumpEvents(java.desktop@12.0.1/EventDispatchThread.java:101)
at java.awt.EventDispatchThread.run(java.desktop@12.0.1/EventDispatchThread.java:90)
"DestroyJavaVM" #15 prio=5 os_prio=31 cpu=173.20ms elapsed=126.82s tid=0x00007f9ac2011800 nid=0x1e03 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Java2D Queue Flusher" #16 daemon prio=10 os_prio=31 cpu=599.14ms elapsed=126.53s tid=0x00007f9ac0187000 nid=0x11e07 in Object.wait() [0x000070000e104000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(java.base@12.0.1/Native Method)
- waiting on <no object reference available>
at sun.java2d.opengl.OGLRenderQueue$QueueFlusher.run(java.desktop@12.0.1/OGLRenderQueue.java:205)
- locked <0x000000070055f568> (a sun.java2d.opengl.OGLRenderQueue$QueueFlusher)
at java.lang.Thread.run(java.base@12.0.1/Thread.java:835)
"Java2D Disposer" #17 daemon prio=10 os_prio=31 cpu=0.94ms elapsed=126.47s tid=0x00007f9ac01b1000 nid=0x11717 in Object.wait() [0x000070000e207000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(java.base@12.0.1/Native Method)
- waiting on <no object reference available>
at java.lang.ref.ReferenceQueue.remove(java.base@12.0.1/ReferenceQueue.java:155)
- locked <0x000000070055f768> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(java.base@12.0.1/ReferenceQueue.java:176)
at sun.java2d.Disposer.run(java.desktop@12.0.1/Disposer.java:144)
at java.lang.Thread.run(java.base@12.0.1/Thread.java:835)
"TimerQueue" #22 daemon prio=5 os_prio=31 cpu=23.30ms elapsed=120.53s tid=0x00007f9abfc2f000 nid=0x15537 waiting on condition [0x000070000e30a000]
java.lang.Thread.State: WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@12.0.1/Native Method)
- parking to wait for <0x0000000700551ee8> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(java.base@12.0.1/LockSupport.java:194)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(java.base@12.0.1/AbstractQueuedSynchronizer.java:2081)
at java.util.concurrent.DelayQueue.take(java.base@12.0.1/DelayQueue.java:217)
at javax.swing.TimerQueue.run(java.desktop@12.0.1/TimerQueue.java:171)
at java.lang.Thread.run(java.base@12.0.1/Thread.java:835)
"SwingWorker-pool-1-thread-1" #23 daemon prio=5 os_prio=31 cpu=189.72ms elapsed=105.85s tid=0x00007f9ac02f3800 nid=0x7e4b waiting on condition [0x000070000dd72000]
java.lang.Thread.State: WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@12.0.1/Native Method)
- parking to wait for <0x00000007005604b8> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(java.base@12.0.1/LockSupport.java:194)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(java.base@12.0.1/AbstractQueuedSynchronizer.java:2081)
at java.util.concurrent.LinkedBlockingQueue.take(java.base@12.0.1/LinkedBlockingQueue.java:433)
at java.util.concurrent.ThreadPoolExecutor.getTask(java.base@12.0.1/ThreadPoolExecutor.java:1054)
at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@12.0.1/ThreadPoolExecutor.java:1114)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@12.0.1/ThreadPoolExecutor.java:628)
at java.lang.Thread.run(java.base@12.0.1/Thread.java:835)
"HttpClient-1-SelectorManager" #24 daemon prio=5 os_prio=31 cpu=38.46ms elapsed=105.78s tid=0x00007f9ac00da800 nid=0x1fc07 runnable [0x000070000eb22000]
java.lang.Thread.State: RUNNABLE
at sun.nio.ch.KQueue.poll(java.base@12.0.1/Native Method)
at sun.nio.ch.KQueueSelectorImpl.doSelect(java.base@12.0.1/KQueueSelectorImpl.java:122)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(java.base@12.0.1/SelectorImpl.java:124)
- locked <0x000000070f61cec0> (a sun.nio.ch.Util$2)
- locked <0x000000070f61ce60> (a sun.nio.ch.KQueueSelectorImpl)
at sun.nio.ch.SelectorImpl.select(java.base@12.0.1/SelectorImpl.java:136)
at jdk.internal.net.http.HttpClientImpl$SelectorManager.run(java.net.http@12.0.1/HttpClientImpl.java:867)
"Attach Listener" #28 daemon prio=9 os_prio=31 cpu=0.97ms elapsed=0.10s tid=0x00007f9ac19ce000 nid=0x16007 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"VM Thread" os_prio=31 cpu=27.33ms elapsed=127.37s tid=0x00007f9abf908800 nid=0x3703 runnable
"GC Thread#0" os_prio=31 cpu=24.36ms elapsed=127.38s tid=0x00007f9abf839000 nid=0x2d03 runnable
"GC Thread#1" os_prio=31 cpu=18.07ms elapsed=105.83s tid=0x00007f9ac188b800 nid=0x28fb runnable
"GC Thread#2" os_prio=31 cpu=22.84ms elapsed=105.83s tid=0x00007f9ac188e800 nid=0x7a0f runnable
"GC Thread#3" os_prio=31 cpu=20.48ms elapsed=105.83s tid=0x00007f9ac19cf800 nid=0x7f07 runnable
"GC Thread#4" os_prio=31 cpu=23.51ms elapsed=105.83s tid=0x00007f9ac288c800 nid=0x9407 runnable
"GC Thread#5" os_prio=31 cpu=20.98ms elapsed=105.83s tid=0x00007f9abf97c000 nid=0x11213 runnable
"G1 Main Marker" os_prio=31 cpu=0.23ms elapsed=127.38s tid=0x00007f9abf852000 nid=0x4f03 runnable
"G1 Conc#0" os_prio=31 cpu=0.03ms elapsed=127.38s tid=0x00007f9abf852800 nid=0x3003 runnable
"G1 Refine#0" os_prio=31 cpu=5.64ms elapsed=127.38s tid=0x00007f9abf8f3800 nid=0x4d03 runnable
"G1 Refine#1" os_prio=31 cpu=2.59ms elapsed=105.82s tid=0x00007f9ac3059800 nid=0x8307 runnable
"G1 Refine#2" os_prio=31 cpu=0.90ms elapsed=105.82s tid=0x00007f9ac2875800 nid=0x1090b runnable
"G1 Young RemSet Sampling" os_prio=31 cpu=22.63ms elapsed=127.38s tid=0x00007f9abf8f4000 nid=0x3303 runnable
"VM Periodic Task Thread" os_prio=31 cpu=86.51ms elapsed=127.34s tid=0x00007f9ac0019800 nid=0x5c03 waiting on condition
JNI global refs: 113, weak refs: 252
欢迎任何建议。
最佳答案
它不会阻塞。请注意，整个线程转储中没有 doInBackground 方法，并且 SwingWorker 线程池处于空闲状态。
更有可能的是，代码抛出了未捕获的异常或错误 - 大概是 NoClassDefFoundError。当您以 -jar 启动应用程序时，类路径中必须缺少某些依赖项。
关于java - 仅从 jar 文件运行时，新 org.json.JSONObject(String) 无限期阻塞，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/58504794/