更新:这不仅适用于 AsyncAppender。也发生在控制台一上。
我遇到了 AsyncAppender 的奇怪行为,这种行为很少发生但危害很大。
这是代码片段:
public void testNPE() {
try {
try {
throw new NullPointerException();
} catch (NullPointerException e) {
throw new RuntimeException(e);
}
} catch (RuntimeException e) {
logger.error("Catcha!" + e.getLocalizedMessage(), e);
}
}
可能的结果应该是:
07.12.12 10:21:34,904 ERROR [main] >> [com.ubs.eqdel.markitfeed.core.RetrieverTest:74] Catcha! java.lang.NullPointerException
java.lang.RuntimeException: java.lang.NullPointerException
at com.ubs.eqdel.markitfeed.core.RetrieverTest.testNPE(RetrieverTest.java:71)
...
Caused by: java.lang.NullPointerException
at com.ubs.eqdel.markitfeed.core.RetrieverTest.testNPE(RetrieverTest.java:69)
... 25 more
但是对于 20 次尝试中的 5 次,我看到:
Exception in thread "Dispatcher-Thread-0" java.lang.NullPointerException
at java.io.Writer.write(Writer.java:140)
at org.apache.log4j.helpers.CountingQuietWriter.write(CountingQuietWriter.java:45)
at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:309)
at org.apache.log4j.RollingFileAppender.subAppend(RollingFileAppender.java:263)
at org.apache.log4j.WriterAppender.append(WriterAppender.java:160)
at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)
at org.apache.log4j.AsyncAppender$Dispatcher.run(AsyncAppender.java:583)
at java.lang.T07.12.12 10:23:54,972 ERROR [main] >> [com.ubs.eqdel.markitfeed.core.RetrieverTest:74] Catcha! java.lang.NullPointerException
java.lang.RuntimeException: java.lang.NullPointerException
at com.ubs.eqdel.markitfeed.core.RetrieverTest.testNPE(RetrieverTest.java:71)
...
Caused by: java.lang.NullPointerException
at com.ubs.eqdel.markitfeed.core.RetrieverTest.testNPE(RetrieverTest.java:69)
... 25 more
AsyncAppender 有什么问题?有没有人面临同样的情况?解决方法是什么?