在DateTimeFormatter类文档定义了不同的符号u为一年,y一年的时代:https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#patterns
年份和年份有什么区别？
我正在编写一个 Java 应用程序来路由大量并发消息。该应用程序使用 Logback 框架进行日志记录，我发现应用程序挂起时出现了令人惊讶的行为。在堆栈跟踪中，我可以看到应用程序线程卡在日志调用中：
"New I/O client worker #1-1" #125 prio=5 os_prio=0 tid=0x00007f0524017000 nid=0x29f3 waiting on condition [0x00007f052ecea000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00007f089c4a7e88> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
at java.util.concurrent.ArrayBlockingQueue.remainingCapacity(ArrayBlockingQueue.java:468)
at ch.qos.logback.core.AsyncAppenderBase.isQueueBelowDiscardingThreshold(AsyncAppenderBase.java:152)
at ch.qos.logback.core.AsyncAppenderBase.append(AsyncAppenderBase.java:144)
at ch.qos.logback.core.UnsynchronizedAppenderBase.doAppend(UnsynchronizedAppenderBase.java:84)
at ch.qos.logback.core.spi.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:51)
at ch.qos.logback.classic.Logger.appendLoopOnAppenders(Logger.java:270)
at ch.qos.logback.classic.Logger.callAppenders(Logger.java:257)
at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:421)
at ch.qos.logback.classic.Logger.filterAndLog_0_Or3Plus(Logger.java:383)
at ch.qos.logback.classic.Logger.info(Logger.java:579)
at com.application.ClientListener$6.operationComplete(***.java:514)
- locked <0x00007f089c372b60> (a com.application.ClientListener)
at org.jboss.netty.channel.DefaultChannelFuture.notifyListener(DefaultChannelFuture.java:381)
at org.jboss.netty.channel.DefaultChannelFuture.notifyListeners(DefaultChannelFuture.java:372)
at org.jboss.netty.channel.DefaultChannelFuture.setSuccess(DefaultChannelFuture.java:316)
at org.jboss.netty.channel.socket.nio.NioWorker$RegisterTask.run(NioWorker.java:776) …