运行GWT应用程序时出现JReleakPrevention.GCDaemonFail错误

Question

在运行简单的GWT应用程序时获取错误。当我用ant通过命令行运行时，它工作得很好，但在IntelliJ中导入后，我得到了这个错误。不知道为什么我会得到这个错误：

The code server is ready at http://127.0.0.1:9876/
Code server started in 9.247 s ms
2019-11-09 01:07:02.250:INFO:oejs.ServerConnector:main: Started ServerConnector@1d54b16e{HTTP/1.1}{127.0.0.1:9876}
2019-11-09 01:07:02.250:INFO:oejs.Server:main: Started @10313ms
**[ERROR] jreLeakPrevention.gcDaemonFail
java.lang.ClassNotFoundException: sun.misc.GC**
  at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
  at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
  at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
  at java.base/java.lang.Class.forName0(Native Method)
  at java.base/java.lang.Class.forName(Class.java:315)
  at com.google.gwt.dev.shell.jetty.JettyLauncher.jreLeakPrevention(JettyLauncher.java:899)
  at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:722)
  at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:636)
  at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:923)
  at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:706)
  at com.google.gwt.dev.DevMode.main(DevMode.java:432)
2019-11-09 01:07:02.307:INFO:oejs.Server:main: jetty-9.2.z-SNAPSHOT
Starting Jetty on port 8888
   [WARN] Failed startup of context c.g.g.d.s.j.WebAppContextWithReload@e59f292{/,file:/Users/pchenchala/Library/Caches/IntelliJIdea2019.2/gwt/mywebapp.4e8f7f71/MyWebApp.c24f5151/run/www/,STARTING}{/Users/pchenchala/Library/Caches/IntelliJIdea2019.2/gwt/mywebapp.4e8f7f71/MyWebApp.c24f5151/run/www}
java.lang.RuntimeException: Error scanning file GreetingServiceImpl.class
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:708)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parse(AnnotationParser.java:824)
  at org.eclipse.jetty.annotations.AnnotationConfiguration$ParserTask.call(AnnotationConfiguration.java:163)
  at org.eclipse.jetty.annotations.AnnotationConfiguration$1.run(AnnotationConfiguration.java:548)
  at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
  at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
  at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.IllegalArgumentException
  at org.objectweb.asm.ClassReader.<init>(Unknown Source)
  at org.objectweb.asm.ClassReader.<init>(Unknown Source)
  at org.objectweb.asm.ClassReader.<init>(Unknown Source)
  at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:973)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:702)
  ... 10 more
2019-11-09 01:07:05.521:INFO:oejs.ServerConnector:main: Started ServerConnector@539f3a98{HTTP/1.1}{127.0.0.1:8888}
2019-11-09 01:07:05.528:INFO:oejs.Server:main: Started @13591ms
Dev Mode initialized. Startup URL: 
http://127.0.0.1:8888/MyWebApp.html
[ERROR] 503 - GET /MyWebApp.html (127.0.0.1) 301 bytes
   Request headers
      Host: 127.0.0.1:8888
      Connection: keep-alive
      Upgrade-Insecure-Requests: 1
      User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.87

Process finished with exit code 137 (interrupted by signal 9: SIGKILL)

Answer 1

这里有两个错误，它们是不相关的。

java.lang.ClassNotFoundException: sun.misc.GC**
  at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
  at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
  at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
  at java.base/java.lang.Class.forName0(Native Method)
  at java.base/java.lang.Class.forName(Class.java:315)
  at com.google.gwt.dev.shell.jetty.JettyLauncher.jreLeakPrevention(JettyLauncher.java:899)

这是可以忽略的。围绕这一点的检查是为了防止这种事情发生--您正在使用的JRE实现删除该特性。检查这个版本的GWT中的JettyLauncher.java，您会发现以下代码:https://github.com/gwtproject/GWT/blob/a90832fec9a56f4cb83ed009c7048e0a8d196fe8/dev/core/src/com/google/GWT/dev/shell/jetty/jettylauncher.java#l898-l915

    try {
      Class<?> clazz = Class.forName("sun.misc.GC");
      Method method = clazz.getDeclaredMethod("requestLatency",
          new Class[]{long.class});
      method.invoke(null, Long.valueOf(3600000));
    } catch (ClassNotFoundException e) {
      logger.log(TreeLogger.ERROR, "jreLeakPrevention.gcDaemonFail", e);
    } catch (SecurityException e) {
      logger.log(TreeLogger.ERROR, "jreLeakPrevention.gcDaemonFail", e);
    } catch (NoSuchMethodException e) {
      logger.log(TreeLogger.ERROR, "jreLeakPrevention.gcDaemonFail", e);
    } catch (IllegalArgumentException e) {
      logger.log(TreeLogger.ERROR, "jreLeakPrevention.gcDaemonFail", e);
    } catch (IllegalAccessException e) {
      logger.log(TreeLogger.ERROR, "jreLeakPrevention.gcDaemonFail", e);
    } catch (InvocationTargetException e) {
      logger.log(TreeLogger.ERROR, "jreLeakPrevention.gcDaemonFail", e);
    }

这些catch语句让我们记录错误，然后继续。

  [WARN] Failed startup of context c.g.g.d.s.j.WebAppContextWithReload@e59f292{/,file:/Users/pchenchala/Library/Caches/IntelliJIdea2019.2/gwt/mywebapp.4e8f7f71/MyWebApp.c24f5151/run/www/,STARTING}{/Users/pchenchala/Library/Caches/IntelliJIdea2019.2/gwt/mywebapp.4e8f7f71/MyWebApp.c24f5151/run/www}
java.lang.RuntimeException: Error scanning file GreetingServiceImpl.class
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:708)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:688)
  at org.eclipse.jetty.annotations.AnnotationParser.parse(AnnotationParser.java:824)
  at org.eclipse.jetty.annotations.AnnotationConfiguration$ParserTask.call(AnnotationConfiguration.java:163)
  at org.eclipse.jetty.annotations.AnnotationConfiguration$1.run(AnnotationConfiguration.java:548)
  at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
  at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
  at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.IllegalArgumentException
  at org.objectweb.asm.ClassReader.<init>(Unknown Source)
  at org.objectweb.asm.ClassReader.<init>(Unknown Source)
  at org.objectweb.asm.ClassReader.<init>(Unknown Source)
  at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:973)
  at org.eclipse.jetty.annotations.AnnotationParser.parseDir(AnnotationParser.java:702)
  ... 10 more

你可能会有更好的运气只张贴关于这个错误，因为另一个错误只是转移注意力。