Tomcat webapp错误 - 应用程序启动线程[AWT-Windows]但未能阻止它 - 内存泄漏？

Question

直到今天，在我的电脑本地进行一些测试时，我没有注意到，Tomcat在日志文件中发布了一个错误。我正在使用Tomcat 6.0.29和Java JDK 1.6。

Dec 1, 2010 12:36:57 pm org.apache.catalina.core.StandardContext reload INFO: Reloading this Context has started Dec 1, 2010 12:36:57 pm org.apache.catalina.loader.WebappClassLoader clearReferencesThreads SEVER: The web application [/AutoSpyder] appears to have started a thread named [AWT-Windows] but has failed to stop it. This is very likely to create a memory leak.

什么？我以前从未见过这个。所以我昨天检查了我的日志文件，果然，这个错误也存在。我不太明白是什么导致了这一点。

我可以假设它必须是我的一个使用java.awt包中对象的servlet吗？如果是这样，我如何查明引起此问题的代码？< / p>

编辑添加线程转储

2010-12-01 14:28:18
Full thread dump Java HotSpot(TM) Client VM (17.1-b03 mixed mode, sharing):

"JMX server connection timeout 34" daemon prio=6 tid=0x03069400 nid=0x960 in Object.wait() [0x0461f000]
   java.lang.Thread.State: TIMED_WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a [I)
    at com.sun.jmx.remote.internal.ServerCommunicatorAdmin$Timeout.run(ServerCommunicatorAdmin.java:150)
    - locked  (a [I)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"RMI Scheduler(0)" daemon prio=6 tid=0x03069000 nid=0xe88 waiting on condition [0x045cf000]
   java.lang.Thread.State: TIMED_WAITING (parking)
    at sun.misc.Unsafe.park(Native Method)
    - parking to wait for   (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
    at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:198)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2025)
    at java.util.concurrent.DelayQueue.take(DelayQueue.java:164)
    at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:609)
    at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:602)
    at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:947)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"RMI TCP Connection(1)-192.168.0.102" daemon prio=6 tid=0x0308a400 nid=0xebc runnable [0x0457f000]
   java.lang.Thread.State: RUNNABLE
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(SocketInputStream.java:129)
    at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
    at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
    - locked  (a java.io.BufferedInputStream)
    at java.io.FilterInputStream.read(FilterInputStream.java:66)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:517)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    -  (a java.util.concurrent.locks.ReentrantLock$NonfairSync)

"RMI TCP Accept-0" daemon prio=6 tid=0x039e0c00 nid=0xc68 runnable [0x0452f000]
   java.lang.Thread.State: RUNNABLE
    at java.net.PlainSocketImpl.socketAccept(Native Method)
    at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:390)
    - locked  (a java.net.SocksSocketImpl)
    at java.net.ServerSocket.implAccept(ServerSocket.java:453)
    at java.net.ServerSocket.accept(ServerSocket.java:421)
    at sun.management.jmxremote.LocalRMIServerSocketFactory$1.accept(LocalRMIServerSocketFactory.java:34)
    at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:369)
    at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:341)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"AWT-Windows" daemon prio=6 tid=0x02b65400 nid=0x7c4 runnable [0x042cf000]
   java.lang.Thread.State: RUNNABLE
    at sun.awt.windows.WToolkit.eventLoop(Native Method)
    at sun.awt.windows.WToolkit.run(WToolkit.java:293)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"Java2D Disposer" daemon prio=10 tid=0x02fccc00 nid=0x93c in Object.wait() [0x039df000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a java.lang.ref.ReferenceQueue$Lock)
    at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118)
    - locked  (a java.lang.ref.ReferenceQueue$Lock)
    at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134)
    at sun.java2d.Disposer.run(Disposer.java:127)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-6" daemon prio=6 tid=0x03322800 nid=0xfec in Object.wait() [0x0395f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
    - locked  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-5" daemon prio=6 tid=0x02ba5c00 nid=0xdbc in Object.wait() [0x0390f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
    - locked  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-4" daemon prio=6 tid=0x02ff6400 nid=0xa1c in Object.wait() [0x038bf000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
    - locked  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-3" daemon prio=6 tid=0x0317e400 nid=0x850 in Object.wait() [0x0386f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
    - locked  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-2" daemon prio=6 tid=0x03314800 nid=0xf9c in Object.wait() [0x0381f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
    - locked  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-1" daemon prio=6 tid=0x02efe800 nid=0x250 in Object.wait() [0x037cf000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
    - locked  (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"TP-Monitor" daemon prio=6 tid=0x02eed800 nid=0xd64 in Object.wait() [0x0375f000]
   java.lang.Thread.State: TIMED_WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable)
    at org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable.run(ThreadPool.java:565)
    - locked  (a org.apache.tomcat.util.threads.ThreadPool$MonitorRunnable)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"TP-Processor4" daemon prio=6 tid=0x0318b000 nid=0x998 runnable [0x0370f000]
   java.lang.Thread.State: RUNNABLE
    at java.net.PlainSocketImpl.socketAccept(Native Method)
    at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:390)
    - locked  (a java.net.SocksSocketImpl)
    at java.net.ServerSocket.implAccept(ServerSocket.java:453)
    at java.net.ServerSocket.accept(ServerSocket.java:421)
    at org.apache.jk.common.ChannelSocket.accept(ChannelSocket.java:312)
    at org.apache.jk.common.ChannelSocket.acceptConnections(ChannelSocket.java:666)
    at org.apache.jk.common.ChannelSocket$SocketAcceptor.runIt(ChannelSocket.java:877)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"TP-Processor3" daemon prio=6 tid=0x0308f800 nid=0x92c in Object.wait() [0x036bf000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:662)
    - locked  (a org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"TP-Processor2" daemon prio=6 tid=0x03192400 nid=0xfac in Object.wait() [0x0366f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:662)
    - locked  (a org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"TP-Processor1" daemon prio=6 tid=0x03182400 nid=0x8d8 in Object.wait() [0x0361f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
    at java.lang.Object.wait(Object.java:485)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:662)
    - locked  (a org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"http-8080-Acceptor-0" daemon prio=6 tid=0x03172400 nid=0xf04 runnable [0x035cf000]
   java.lang.Thread.State: RUNNABLE
    at java.net.PlainSocketImpl.socketAccept(Native Method)
    at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:390)
    - locked  (a java.net.SocksSocketImpl)
    at java.net.ServerSocket.implAccept(ServerSocket.java:453)
    at java.net.ServerSocket.accept(ServerSocket.java:421)
    at org.apache.tomcat.util.net.DefaultServerSocketFactory.acceptSocket(DefaultServerSocketFactory.java:61)
    at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:352)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"ContainerBackgroundProcessor[StandardEngine[Catalina]]" daemon prio=6 tid=0x03163400 nid=0xbe8 waiting on condition [0x0357f000]
   java.lang.Thread.State: TIMED_WAITING (sleeping)
    at java.lang.Thread.sleep(Native Method)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1579)
    at java.lang.Thread.run(Thread.java:662)

   Locked ownable synchronizers:
    - None

"GC Daemon" daemon prio=2 tid=0x0307bc00 nid=0x110 in Object.wait() [0x0349f000]
   java.lang.Thread.State: TIMED_WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a sun.misc.GC$LatencyLock)
    at sun.misc.GC$Daemon.run(GC.java:100)
    - locked  (a sun.misc.GC$LatencyLock)

   Locked ownable synchronizers:
    - None

"Low Memory Detector" daemon prio=6 tid=0x02aecc00 nid=0x5b4 runnable [0x00000000]
   java.lang.Thread.State: RUNNABLE

   Locked ownable synchronizers:
    - None

"CompilerThread0" daemon prio=10 tid=0x02ae7000 nid=0x798 waiting on condition [0x00000000]
   java.lang.Thread.State: RUNNABLE

   Locked ownable synchronizers:
    - None

"Attach Listener" daemon prio=10 tid=0x02ae5800 nid=0xddc waiting on condition [0x00000000]
   java.lang.Thread.State: RUNNABLE

   Locked ownable synchronizers:
    - None

"Signal Dispatcher" daemon prio=10 tid=0x02ae4000 nid=0xc00 runnable [0x00000000]
   java.lang.Thread.State: RUNNABLE

   Locked ownable synchronizers:
    - None

"Finalizer" daemon prio=8 tid=0x02add400 nid=0x378 in Object.wait() [0x02caf000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a java.lang.ref.ReferenceQueue$Lock)
    at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118)
    - locked  (a java.lang.ref.ReferenceQueue$Lock)
    at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134)
    at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159)

   Locked ownable synchronizers:
    - None

"Reference Handler" daemon prio=10 tid=0x02adbc00 nid=0x474 in Object.wait() [0x02c5f000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    - waiting on  (a java.lang.ref.Reference$Lock)
    at java.lang.Object.wait(Object.java:485)
    at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116)
    - locked  (a java.lang.ref.Reference$Lock)

   Locked ownable synchronizers:
    - None

"main" prio=6 tid=0x002b7000 nid=0x14c runnable [0x0090f000]
   java.lang.Thread.State: RUNNABLE
    at java.net.PlainSocketImpl.socketAccept(Native Method)
    at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:390)
    - locked  (a java.net.SocksSocketImpl)
    at java.net.ServerSocket.implAccept(ServerSocket.java:453)
    at java.net.ServerSocket.accept(ServerSocket.java:421)
    at org.apache.catalina.core.StandardServer.await(StandardServer.java:389)
    at org.apache.catalina.startup.Catalina.await(Catalina.java:662)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:614)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)

   Locked ownable synchronizers:
    - None

"VM Thread" prio=10 tid=0x02ada400 nid=0x210 runnable 

"VM Periodic Task Thread" prio=10 tid=0x02aefc00 nid=0x79c waiting on condition 

JNI global references: 1529

Answer 1

尝试进行线程转储以获取服务器上运行的所有线程的列表。由此，您可以根据堆栈跟踪确切地确定哪个类启动了线程

窗

控制台窗口上的

按ctrl + break

的Unix

在命令行中输入：kill -3 <pid>

Answer 2

与Windows（即MS Windows）和底层操作系统的本机调用有关。这些通常是GUI类型的窗口操作，但可能是其他特定于操作系统的东西，例如剪贴板或字体相关。

如果您的代码中没有任何明显的内容可能与触发它的原因有关，那么我就不用担心了 - 对于在Web应用程序中剥离新线程的一般情况，该警告更多如果不充分了解潜在的问题，你不应该明确做些什么。

Answer 3

我们有tomcat服务器和jsf。 JSF客户端将从服务器请求图像并导致AWT-Windows线程开始。似乎因为线程contextClassLoader是WebappClassLoader而导致内存泄漏。

看起来调用Java2DResource会导致创建AWT-Windows线程 -

守护程序线程[http-8080-1]（暂停（进入线程中的方法））
    Thread。（Runnable，String）行：444＆lt; - thread name是AWT-Windows     WToolkit。（）行：244     NativeConstructorAccessorImpl.newInstance0（Constructor，Object []）行：不可用[native method]
    NativeConstructorAccessorImpl.newInstance（Object []）line：39
    DelegatingConstructorAccessorImpl.newInstance（Object []）line：27
    Constructor.newInstance（Object ...）行：513     Class.newInstance0（）行：355
    Class.newInstance（）行：308
    工具包$ 2.run（）行：846
    AccessController.doPrivileged（PrivilegedAction）行：不可用[native method]
    Toolkit.getDefaultToolkit（）行：826
    D3DGraphicsDevice。（）行：47
    SurfaceManagerFactory.createCachingManager（BufferedImage）行：48
    SurfaceManager.getManager（Image）行：54
    SurfaceData.getDestSurfaceData（Image）行：123     Win32GraphicsEnvironment（SunGraphicsEnvironment）.createGraphics（BufferedImage）行：389
    HeadlessGraphicsEnvironment.createGraphics（BufferedImage）行：76
    BufferedImage.createGraphics（）行：1137
    TabStripeImage（Java2Dresource）.getImage（ResourceContext）行：115
    TabStripeImage（Java2Dresource）.send（ResourceContext）行：89
    ResourceLifecycle.sendResource（ResourceContext，InternetResource）行：219     ResourceLifecycle.send（ResourceContext，InternetResource）行：158     InternetResourceService.load（Object，Object）行：335
    LRUMapCache.load（Object，Object）行：116
    LRUMapCache.get（Object，Object）行：87
    InternetResourceService.serviceResource（String，HttpServletRequest，HttpServletResponse）行：195
    InternetResourceService.serviceResource（HttpServletRequest，HttpServletResponse）行：141
    Filter（BaseFilter）.doFilter（ServletRequest，ServletResponse，FilterChain）行：508     Ajax4jsfFilter.doFilter（ServletRequest，ServletResponse，FilterChain）行：56
    SeamFilter $ FilterChainImpl.doFilter（ServletRequest，ServletResponse）行：69
    LoggingFilter.doFilter（ServletRequest，ServletResponse，FilterChain）行：60
    SeamFilter $ FilterChainImpl.doFilter（ServletRequest，ServletResponse）行：69
    SeamFilter.doFilter（ServletRequest，ServletResponse，FilterChain）行：158     ApplicationFilterChain.internalDoFilter（ServletRequest，ServletResponse）行：235
    ApplicationFilterChain.doFilter（ServletRequest，ServletResponse）行：206
    StandardWrapperValve.invoke（请求，响应）行：233
    StandardContextValve.invoke（Request，Response）行：191
    StandardHostValve.invoke（请求，响应）行：127
    ErrorReportValve.invoke（请求，响应）行：102
    AccessLogValve.invoke（请求，响应）行：555
    StandardEngineValve.invoke（请求，响应）行：109     CoyoteAdapter.service（Request，Response）行：298
    Http11AprProcessor.process（long）行：861
    Http11AprProtocol $ Http11ConnectionHandler.process（long）行：579
    AprEndpoint $ Worker.run（）行：1584     Thread.run（）行：619 [局部变量不可用]

Answer 4

看起来你正在运行JMX，我得到的印象是Tomcat JMX服务器可能正在实际设置定时器线程。除了你在JavaRanch上的并行帖子中提到的那些，你在这里的转储中有一个java2D线程。

我不能告诉100％，因为我不知道哪些线程是孤儿线程的父母。如果你能确定，那会有所帮助。

然而，你的仿射变换肯定会拉动图形。这是一个图形功能，将尝试将您的视频卡用作硬件加速器。如果您没有指定无头操作，它将进入您的窗口系统进行操作。

Answer 5

受this thread的启发，我找到了以下解决方案：

您只需要将AWT-Window-Thread附加到System-Classloader而不是Wabapp-Classloader。您可以在ServletContextListener中执行此操作：

public void contextInitialized(ServletContextEvent evt) {
    Thread thread = Thread.currentThread();
    ClassLoader ccl = thread.getContextClassLoader(); // PUSH
    try {
        thread.setContextClassLoader(ClassLoader.getSystemClassLoader());
        Toolkit.getDefaultToolkit().createImage(new byte[]{});
    } finally {
        thread.setContextClassLoader(ccl); // POP
    }
}

Answer 6

你是否正在运行包括某些图形库，如Jasper，JFreechart，LiquidOffice，StyleReport，......可能与AWT交互？

尝试通过提供-Djava.awt.headless = true属性来启动tomcat，以查看是否删除了异常