1java.lang.ThreadGroup[name=main,maxpri=10] 2 java.lang.ThreadGroup[name=system,maxpri=10] 3 main 4 10 5 false 6java.lang.ThreadGroup[name=system,maxpri=10] 7 null 8 system 9 10 10 false 11main: 12 [Thread[main,5,main]] 13 [] 14system: 15 [Thread[FinalizerDaemon,5,system], Thread[FinalizerWatchdogDaemon,5,system], Thread[HeapTaskDaemon,5,system], Thread[ReferenceQueueDaemon,5,system], Thread[Signal Catcher,5,system]] 16 [java.lang.ThreadGroup[name=main,maxpri=10]] 17art.Test925$CustomThreadGroup[name=TEST GROUP,maxpri=10] 18 java.lang.ThreadGroup[name=main,maxpri=10] 19 TEST GROUP 20 10 21 false 22