"Finalizer" #3 daemon prio=8 os_prio=1 tid=0x000000001776a800 nid=0xdac in Object.wait() [0x0000000018b6f000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00000000d6108ec8> (a java.lang.ref.ReferenceQueue
Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209)
"Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x0000000017723800 nid=0x1670 in Object.wait() [0x00000000189ef000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x00000000d6106b68> (a java.lang.ref.Reference
Lock) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)
"VM Thread" os_prio=2 tid=0x000000001771b800 nid=0x604 runnable
"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x0000000001c9d800 nid=0x9f0 runnable
"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x0000000001c9f000 nid=0x154c runnable
"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x0000000001ca0800 nid=0xcd0 runnable
"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x0000000001ca2000 nid=0x1e58 runnable
"VM Periodic Task Thread" os_prio=2 tid=0x0000000018c5a000 nid=0x1b58 waiting on condition
JNI global references: 33
/* 此处可以看待死锁的相关信息！ */ Found one Java-level deadlock:"Thread-1": waiting to lock monitor 0x0000000017729fc8 (object 0x00000000d629b4d8, a java.lang.Object), which is held by "Thread-0" "Thread-0": waiting to lock monitor 0x0000000017727738 (object 0x00000000d629b4e8, a java.lang.Object), which is held by "Thread-1"
Java stack information for the threads listed above:"Thread-1": at com.leo.interview.SimpleDeadLock
A.run(SimpleDeadLock.java:34) - waiting to lock <0x00000000d629b4e8> (a java.lang.Object) - locked <0x00000000d629b4d8> (a java.lang.Object)
Found 1 deadlock.
/* 内存使用状况，详情得看JVM方面的书 */ Heap PSYoungGen total 37888K, used 4590K [0x00000000d6100000, 0x00000000d8b00000, 0x0000000100000000) eden space 32768K, 14% used [0x00000000d6100000,0x00000000d657b968,0x00000000d8100000) from space 5120K, 0% used [0x00000000d8600000,0x00000000d8600000,0x00000000d8b00000) to space 5120K, 0% used [0x00000000d8100000,0x00000000d8100000,0x00000000d8600000) ParOldGen total 86016K, used 0K [0x0000000082200000, 0x0000000087600000, 0x00000000d6100000) object space 86016K, 0% used [0x0000000082200000,0x0000000082200000,0x0000000087600000) Metaspace used 3474K, capacity 4500K, committed 4864K, reserved 1056768K class space used 382K, capacity 388K, committed 512K, reserved 1048576K 19、为什么我们调用start()方法时会执行run()方法，为什么我们不能直接调用run()方法？ 当你调用start()方法时你将创建新的线程，并且执行在run()方法里的代码。
但是如果你直接调用run()方法，它不会创建新的线程也不会执行调用线程的代码，只会把run方法当作普通方法去执行。
20、Java中你怎样唤醒一个阻塞的线程？
在Java发展史上曾经使用suspend()、resume()方法对于线程进行阻塞唤醒，但随之出现很多问题，比较典型的还是死锁问题。
解决方案可以使用以对象为目标的阻塞，即利用Object类的wait()和notify()方法实现线程阻塞。