一、Javac（java compiler）

1、功能：javac是一种前端编译器，负责将源代码转换为字节码。

2、例子

（1）代码

  1. public class TestJavac {
  2.     static class Person{
  3.         private String name;
  4.         private Integer age;
  5.         public Person() {
  6.         }
  8.         public Person(String name, Integer age) {
  9.             this.name = name;
  10.             this.age = age;
  11.         }
  13.         public String getName() {
  14.             return name;
  15.         }
  17.         public void setName(String name) {
  18.             this.name = name;
  19.         }
  21.         public Integer getAge() {
  22.             return age;
  23.         }
  25.         public void setAge(Integer age) {
  26.             this.age = age;
  27.         }
  28.     }
  30.     public static void main(String[] args) {
  31.         System.out.println("Test Javac");
  32.         Person javac = new Person("Javac", 14);
  33.         System.out.println(javac.getName());
  34.         System.out.println(javac.getAge());
  35.     }
  36. }

（2）执行javac命令

  1. C:\Users\HBKJ\Desktop\TestJavac>javac TestJavac.java
  2. C:\Users\HBKJ\Desktop\TestJavac>dir
  3.     C:\Users\HBKJ\Desktop\TestJavac 的目录
  4.     2018/07/21  12:30    <DIR>          .
  5.     2018/07/21  12:30    <DIR>          ..
  6.     2018/07/21  12:26               774 TestJavac$Person.class // 内部类
  7.     2018/07/21  12:26               783 TestJavac.class
  8.     2018/07/21  12:26               842 TestJavac.java
  9.                    3 个文件          2,399 字节
  10.                    2 个目录 13,931,593,728 可用字节

二、javap

1、功能：javap是Java字节码文件分解器，能够反编译javac生成的字节码；也能够查看java编译器生成的字节码，用于分解class文件。

2、例子

（1）命令：javap -p

  1. C:\Users\HBKJ\Desktop\TestJavac>javap -p TestJavac.class
  2. Compiled from "TestJavac.java"
  3. public class TestJavac {
  4.   public TestJavac();
  5.   public static void main(java.lang.String[]);
  6. }

（2）命令：javap -c

  1. C:\Users\HBKJ\Desktop\TestJavac>javap -c TestJavac.class
  2. Compiled from "TestJavac.java"
  3. public class TestJavac {
  4.   public TestJavac(); // 构造器
  5.     Code:
  6.        0: aload_0
  7.        1: invokespecial #1                  // Method java/lang/Object."<init>":()V
  8.        4: return
  10.   public static void main(java.lang.String[]);
  11.     Code:
  12.        0: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
  13.        3: ldc           #3                  // String Test Javac
  14.        5: invokevirtual #4                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
  15.        8: new           #5                  // class TestJavac$Person
  16.       11: dup
  17.       12: ldc           #6                  // String Javac
  18.       14: bipush        14
  19.       16: invokestatic  #7                  // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
  20.       19: invokespecial #8                  // Method TestJavac$Person."<init>":(Ljava/lang/String;Ljava/lang/Integer;)V
  21.       22: astore_1
  22.       23: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
  23.       26: aload_1
  24.       27: invokevirtual #9                  // Method TestJavac$Person.getName:()Ljava/lang/String;
  25.       30: invokevirtual #4                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
  26.       33: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
  27.       36: aload_1
  28.       37: invokevirtual #10                 // Method TestJavac$Person.getAge:()Ljava/lang/Integer;
  29.       40: invokevirtual #11                 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
  30.       43: return
  31. }

三、jps（JVM Process Status Tool）

1、功能：列出正在运行的虚拟机进程，并显示虚拟机执行主类的名称和这些进程的唯一ID。

2、主要选项

选项 作用
-q 省略主类名称（java8默认参数）
-l 输出主类名称（java10默认参数）
-v 输出虚拟机进程启动时JVM参数

3、例子（Idea IDE进程）

  1. PS C:\Windows\system32> jps
  2. 9024 Jps
  3. 9796 Launcher
  4. 9860
  6. PS C:\Windows\system32> jps -l
  7. 9796 org.jetbrains.jps.cmdline.Launcher
  8. 9860
  9. 8540 jdk.jcmd/sun.tools.jps.Jps
  11. PS C:\Windows\system32> jps -v
  12. 8404 Jps -Dapplication.home=E:\develop\software\java10\jdk -Xms8m -Djdk.module.main=jdk.jcmd
  13. 9796 Launcher -Xmx700m -Djava.awt.headless=true -Djdt.compiler.useSingleThread=true -Dpreload.project.path=E:/develop/project/AlgorithmsLearning -Dpreload.config.path=C:/Users/HBKJ/.IntelliJIdea2018.1/config/options -Dcompile.parallel=false -Drebuild.on.dependency.change=true -Djava.net.preferIPv4Stack=true -Dio.netty.initialSeedUniquifier=7903075717686063478 -Dfile.encoding=GBK -Duser.language=zh -Duser.country=CN -Didea.paths.selector=IntelliJIdea2018.1 -Didea.home.path=D:\software\IntelliJ IDEA 2018.1.1 -Didea.config.path=C:\Users\HBKJ\.IntelliJIdea2018.1\config -Didea.plugins.path=C:\Users\HBKJ\.IntelliJIdea2018.1\config\plugins -Djps.log.dir=C:/Users/HBKJ/.IntelliJIdea2018.1/system/log/build-log -Djps.fallback.jdk.home=D:/software/IntelliJ IDEA 2018.1.1/jre64 -Djps.fallback.jdk.version=1.8.0_152-release -Dio.netty.noUnsafe=true -Djava.io.tmpdir=C:/Users/HBKJ/.IntelliJIdea2018.1/system/compile-server/algorithmslearning_af8be974/_temp_ -Djps.backward.ref.index.builder=true -Dkotlin.incremental.compilation=true -Dkotlin.
  14. 9860  -Xms128m -Xmx750m -XX:ReservedCodeCacheSize=240m -XX:+UseConcMarkSweepGC -XX:SoftRefLRUPolicyMSPerMB=50 -ea -Dsun.io.useCanonCaches=false -Djava.net.preferIPv4Stack=true -XX:+HeapDumpOnOutOfMemoryError -XX:-OmitStackTraceInFastThrow -javaagent:D:/software/IntelliJ IDEA 2018.1.1/bin/JetbrainsCrack-2.7-release-str.jar -Djb.vmOptionsFile=D:\software\IntelliJ IDEA 2018.1.1\bin\idea64.exe.vmoptions -Didea.jre.check=true -Dide.native.launcher=true -Didea.paths.selector=IntelliJIdea2018.1 -XX:ErrorFile=C:\Users\HBKJ\java_error_in_idea_%p.log -XX:HeapDumpPath=C:\Users\HBKJ\java_error_in_idea.hprof

四、jstack（Stack Trace for java）

1、功能：生成JVM当前时间的线程快照（threaddump或javacore文件）。

  • 线程快照：当前JVM内每一条线程正在执行的方法堆栈的集合，生成线程快照的主要目的是为了定位线程长时间停顿的原因。
  • 线程长时间停顿情况：死锁、死循环、请求外部资源等

2、主要选项

选项 作用
-l 同时显示锁的附加信息

3、例子（Idea IDE进程）

  1. PS C:\Users\HBKJ> jstack 9796
  2. 2018-07-14 14:33:38
  3. Full thread dump Java HotSpot(TM) 64-Bit Server VM (10.0.1+10 mixed mode):
  5. Threads class SMR info:
  6. _java_thread_list=0x000001a3b0b585f0, length=14, elements={
  7. 0x000001a3aea36000, 0x000001a3aea37000, 0x000001a3aea3d800, 0x000001a3aea3e000,
  8. 0x000001a3af2c8800, 0x000001a3af2d1000, 0x000001a3af2d4000, 0x000001a3af2d8000,
  9. 0x000001a3af2e8800, 0x000001a3af47f800, 0x000001a3af484000, 0x000001a3afb2f000,
  10. 0x000001a38ff10000, 0x000001a3b0cb0800
  11. }
  13. "Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x000001a3aea36000 nid=0x1e44 waiting on condition  [0x0000008ea28ff000]
  14.    java.lang.Thread.State: RUNNABLE
  15.         at java.lang.ref.Reference.waitForReferencePendingList(java.base@10.0.1/Native Method)
  16.         at java.lang.ref.Reference.processPendingReferences(java.base@10.0.1/Reference.java:174)
  17.         at java.lang.ref.Reference.access$000(java.base@10.0.1/Reference.java:44)
  18.         at java.lang.ref.Reference$ReferenceHandler.run(java.base@10.0.1/Reference.java:138)
  20. "Finalizer" #3 daemon prio=8 os_prio=1 tid=0x000001a3aea37000 nid=0x1308 in Object.wait()  [0x0000008ea29fe000]
  21.    java.lang.Thread.State: WAITING (on object monitor)
  22.         at java.lang.Object.wait(java.base@10.0.1/Native Method)
  23.         - waiting on <0x00000000d4e5e9c0> (a java.lang.ref.ReferenceQueue$Lock)
  24.         at java.lang.ref.ReferenceQueue.remove(java.base@10.0.1/ReferenceQueue.java:151)
  25.         - waiting to re-lock in wait() <0x00000000d4e5e9c0> (a java.lang.ref.ReferenceQueue$Lock)
  26.         at java.lang.ref.ReferenceQueue.remove(java.base@10.0.1/ReferenceQueue.java:172)
  27.         at java.lang.ref.Finalizer$FinalizerThread.run(java.base@10.0.1/Finalizer.java:216)
  29. "Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x000001a3aea3d800 nid=0x196c runnable  [0x0000000000000000]
  30.    java.lang.Thread.State: RUNNABLE
  32. "Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x000001a3aea3e000 nid=0x3210 waiting on condition  [0x0000000000000000]
  33.    java.lang.Thread.State: RUNNABLE
  35. "C2 CompilerThread0" #6 daemon prio=9 os_prio=2 tid=0x000001a3af2c8800 nid=0xe08 waiting on condition  [0x0000000000000000]
  36.    java.lang.Thread.State: RUNNABLE
  37.    No compile task
  39. "C2 CompilerThread1" #7 daemon prio=9 os_prio=2 tid=0x000001a3af2d1000 nid=0x2a94 waiting on condition  [0x0000000000000000]
  40.    java.lang.Thread.State: RUNNABLE
  41.    No compile task
  43. "C2 CompilerThread2" #8 daemon prio=9 os_prio=2 tid=0x000001a3af2d4000 nid=0x724 waiting on condition  [0x0000000000000000]
  44.    java.lang.Thread.State: RUNNABLE
  45.    No compile task
  47. "C1 CompilerThread3" #9 daemon prio=9 os_prio=2 tid=0x000001a3af2d8000 nid=0x20 waiting on condition  [0x0000000000000000]
  48.    java.lang.Thread.State: RUNNABLE
  49.    No compile task
  51. "Sweeper thread" #10 daemon prio=9 os_prio=2 tid=0x000001a3af2e8800 nid=0x2810 runnable  [0x0000000000000000]
  52.    java.lang.Thread.State: RUNNABLE
  54. "Service Thread" #11 daemon prio=9 os_prio=0 tid=0x000001a3af47f800 nid=0x23a8 runnable  [0x0000000000000000]
  55.    java.lang.Thread.State: RUNNABLE
  57. "Common-Cleaner" #12 daemon prio=8 os_prio=1 tid=0x000001a3af484000 nid=0x29b0 in Object.wait()  [0x0000008ea33ff000]
  58.    java.lang.Thread.State: TIMED_WAITING (on object monitor)
  59.         at java.lang.Object.wait(java.base@10.0.1/Native Method)
  60.         - waiting on <0x00000000d4e213d8> (a java.lang.ref.ReferenceQueue$Lock)
  61.         at java.lang.ref.ReferenceQueue.remove(java.base@10.0.1/ReferenceQueue.java:151)
  62.         - waiting to re-lock in wait() <0x00000000d4e213d8> (a java.lang.ref.ReferenceQueue$Lock)
  63.         at jdk.internal.ref.CleanerImpl.run(java.base@10.0.1/CleanerImpl.java:148)
  64.         at java.lang.Thread.run(java.base@10.0.1/Thread.java:844)
  65.         at jdk.internal.misc.InnocuousThread.run(java.base@10.0.1/InnocuousThread.java:134)
  67. "JPS event loop" #13 prio=5 os_prio=0 tid=0x000001a3afb2f000 nid=0x1674 runnable  [0x0000008ea45fe000]
  68.    java.lang.Thread.State: RUNNABLE
  69.         at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(java.base@10.0.1/Native Method)
  70.         at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(java.base@10.0.1/WindowsSelectorImpl.java:296)
  71.         at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(java.base@10.0.1/WindowsSelectorImpl.java:278)
  72.         at sun.nio.ch.WindowsSelectorImpl.doSelect(java.base@10.0.1/WindowsSelectorImpl.java:159)
  73.         at sun.nio.ch.SelectorImpl.lockAndDoSelect(java.base@10.0.1/SelectorImpl.java:89)
  74.         - locked <0x00000000d4e620c8> (a io.netty.channel.nio.SelectedSelectionKeySet)
  75.         - locked <0x00000000d4e620e0> (a java.util.Collections$UnmodifiableSet)
  76.         - locked <0x00000000d4e62048> (a sun.nio.ch.WindowsSelectorImpl)
  77.         at sun.nio.ch.SelectorImpl.select(java.base@10.0.1/SelectorImpl.java:100)
  78.         at io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62)
  79.         at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:752)
  80.         at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:408)
  81.         at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
  82.         at java.lang.Thread.run(java.base@10.0.1/Thread.java:844)
  84. "DestroyJavaVM" #15 prio=5 os_prio=0 tid=0x000001a38ff10000 nid=0x2278 waiting on condition  [0x0000000000000000]
  85.    java.lang.Thread.State: RUNNABLE
  87. "NettythreadDeathWatcher-2-1" #17 daemon prio=1 os_prio=-2 tid=0x000001a3b0cb0800 nid=0x2740 waiting on condition  [0x0000008ea48fe000]
  88.    java.lang.Thread.State: TIMED_WAITING (sleeping)
  89.         at java.lang.Thread.sleep(java.base@10.0.1/Native Method)
  90.         at io.netty.util.ThreadDeathWatcher$Watcher.run(ThreadDeathWatcher.java:152)
  91.         at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
  92.         at java.lang.Thread.run(java.base@10.0.1/Thread.java:844)
  94. "VM Thread" os_prio=2 tid=0x000001a3aea31800 nid=0x1de0 runnable
  96. "GC Thread#0" os_prio=2 tid=0x000001a38ff2c000 nid=0x9c8 runnable
  98. "GC Thread#1" os_prio=2 tid=0x000001a38ff2d800 nid=0x410 runnable
  100. "GC Thread#2" os_prio=2 tid=0x000001a38ff30000 nid=0x28e4 runnable
  102. "GC Thread#3" os_prio=2 tid=0x000001a38ff33800 nid=0x22a0 runnable
  104. "GC Thread#4" os_prio=2 tid=0x000001a38ff35800 nid=0x16e4 runnable
  106. "GC Thread#5" os_prio=2 tid=0x000001a38ff3a800 nid=0xfd8 runnable
  108. "GC Thread#6" os_prio=2 tid=0x000001a38ff3e000 nid=0x21a0 runnable
  110. "GC Thread#7" os_prio=2 tid=0x000001a38ff3f000 nid=0x1b88 runnable
  112. "G1 Main Marker" os_prio=2 tid=0x000001a38ff7e800 nid=0x2cd4 runnable
  114. "G1 Conc#0" os_prio=2 tid=0x000001a38ff81800 nid=0xe1c runnable
  116. "G1 Conc#1" os_prio=2 tid=0x000001a38ff82800 nid=0x91c runnable
  118. "G1 Refine#0" os_prio=2 tid=0x000001a38ffde800 nid=0x3350 runnable
  120. "G1 Refine#1" os_prio=2 tid=0x000001a3ae8ce000 nid=0x2d74 runnable
  122. "G1 Refine#2" os_prio=2 tid=0x000001a3ae8d0000 nid=0x59c runnable
  124. "G1 Refine#3" os_prio=2 tid=0x000001a3ae8d0800 nid=0x2f50 runnable
  126. "G1 Refine#4" os_prio=2 tid=0x000001a3ae8d5800 nid=0x2750 runnable
  128. "G1 Refine#5" os_prio=2 tid=0x000001a3ae8d8800 nid=0xa18 runnable
  130. "G1 Refine#6" os_prio=2 tid=0x000001a3ae8db000 nid=0x1c04 runnable
  132. "G1 Refine#7" os_prio=2 tid=0x000001a3ae8ec000 nid=0x3220 runnable
  134. "G1 Young RemSet Sampling" os_prio=2 tid=0x000001a3ae8ec800 nid=0x23cc runnable
  135. "VM Periodic Task Thread" os_prio=2 tid=0x000001a3af485000 nid=0x1540 waiting on condition
  137. JNI global references: 14
  139. #################################################
  140. # 使用-l选项将输出Locked ownable synchronizers 内容
  141. #################################################
  142. PS C:\Users\HBKJ> jstack -l  9796
  143. 2018-07-14 14:41:41
  144. Full thread dump Java HotSpot(TM) 64-Bit Server VM (10.0.1+10 mixed mode):
  146. Threads class SMR info:
  147. _java_thread_list=0x000001a3b0b585f0, length=14, elements={
  148. 0x000001a3aea36000, 0x000001a3aea37000, 0x000001a3aea3d800, 0x000001a3aea3e000,
  149. 0x000001a3af2c8800, 0x000001a3af2d1000, 0x000001a3af2d4000, 0x000001a3af2d8000,
  150. 0x000001a3af2e8800, 0x000001a3af47f800, 0x000001a3af484000, 0x000001a3afb2f000,
  151. 0x000001a38ff10000, 0x000001a3b0cb0800
  152. }
  154. "Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x000001a3aea36000 nid=0x1e44 waiting on condition  [0x0000008ea28ff000]
  155.    java.lang.Thread.State: RUNNABLE
  156.         at java.lang.ref.Reference.waitForReferencePendingList(java.base@10.0.1/Native Method)
  157.         at java.lang.ref.Reference.processPendingReferences(java.base@10.0.1/Reference.java:174)
  158.         at java.lang.ref.Reference.access$000(java.base@10.0.1/Reference.java:44)
  159.         at java.lang.ref.Reference$ReferenceHandler.run(java.base@10.0.1/Reference.java:138)
  161.    Locked ownable synchronizers:
  162.         - None
  164. "Finalizer" #3 daemon prio=8 os_prio=1 tid=0x000001a3aea37000 nid=0x1308 in Object.wait()  [0x0000008ea29fe000]
  165.    java.lang.Thread.State: WAITING (on object monitor)
  166.         at java.lang.Object.wait(java.base@10.0.1/Native Method)
  167.         - waiting on <0x00000000d4e5e9c0> (a java.lang.ref.ReferenceQueue$Lock)
  168.         at java.lang.ref.ReferenceQueue.remove(java.base@10.0.1/ReferenceQueue.java:151)
  169.         - waiting to re-lock in wait() <0x00000000d4e5e9c0> (a java.lang.ref.ReferenceQueue$Lock)
  170.         at java.lang.ref.ReferenceQueue.remove(java.base@10.0.1/ReferenceQueue.java:172)
  171.         at java.lang.ref.Finalizer$FinalizerThread.run(java.base@10.0.1/Finalizer.java:216)
  173.    Locked ownable synchronizers:
  174.         - None
  176. "Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x000001a3aea3d800 nid=0x196c runnable  [0x0000000000000000]
  177.    java.lang.Thread.State: RUNNABLE
  179.    Locked ownable synchronizers:
  180.         - None
  182. "Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x000001a3aea3e000 nid=0x3210 waiting on condition  [0x0000000000000000]
  183.    java.lang.Thread.State: RUNNABLE
  185.    Locked ownable synchronizers:
  186.         - None
  188. "C2 CompilerThread0" #6 daemon prio=9 os_prio=2 tid=0x000001a3af2c8800 nid=0xe08 waiting on condition  [0x0000000000000000]
  189.    java.lang.Thread.State: RUNNABLE
  190.    No compile task
  192.    Locked ownable synchronizers:
  193.         - None
  195. "C2 CompilerThread1" #7 daemon prio=9 os_prio=2 tid=0x000001a3af2d1000 nid=0x2a94 waiting on condition  [0x0000000000000000]
  196.    java.lang.Thread.State: RUNNABLE
  197.    No compile task
  199.    Locked ownable synchronizers:
  200.         - None
  202. "C2 CompilerThread2" #8 daemon prio=9 os_prio=2 tid=0x000001a3af2d4000 nid=0x724 waiting on condition  [0x0000000000000000]
  203.    java.lang.Thread.State: RUNNABLE
  204.    No compile task
  206.    Locked ownable synchronizers:
  207.         - None
  209. "C1 CompilerThread3" #9 daemon prio=9 os_prio=2 tid=0x000001a3af2d8000 nid=0x20 waiting on condition  [0x0000000000000000]
  210.    java.lang.Thread.State: RUNNABLE
  211.    No compile task
  213.    Locked ownable synchronizers:
  214.         - None
  216. "Sweeper thread" #10 daemon prio=9 os_prio=2 tid=0x000001a3af2e8800 nid=0x2810 runnable  [0x0000000000000000]
  217.    java.lang.Thread.State: RUNNABLE
  219.    Locked ownable synchronizers:
  220.         - None
  222. "Service Thread" #11 daemon prio=9 os_prio=0 tid=0x000001a3af47f800 nid=0x23a8 runnable  [0x0000000000000000]
  223.    java.lang.Thread.State: RUNNABLE
  225.    Locked ownable synchronizers:
  226.         - None
  228. "Common-Cleaner" #12 daemon prio=8 os_prio=1 tid=0x000001a3af484000 nid=0x29b0 in Object.wait()  [0x0000008ea33ff000]
  229.    java.lang.Thread.State: TIMED_WAITING (on object monitor)
  230.         at java.lang.Object.wait(java.base@10.0.1/Native Method)
  231.         - waiting on <0x00000000d4e213d8> (a java.lang.ref.ReferenceQueue$Lock)
  232.         at java.lang.ref.ReferenceQueue.remove(java.base@10.0.1/ReferenceQueue.java:151)
  233.         - waiting to re-lock in wait() <0x00000000d4e213d8> (a java.lang.ref.ReferenceQueue$Lock)
  234.         at jdk.internal.ref.CleanerImpl.run(java.base@10.0.1/CleanerImpl.java:148)
  235.         at java.lang.Thread.run(java.base@10.0.1/Thread.java:844)
  236.         at jdk.internal.misc.InnocuousThread.run(java.base@10.0.1/InnocuousThread.java:134)
  238.    Locked ownable synchronizers:
  239.         - None
  241. "JPS event loop" #13 prio=5 os_prio=0 tid=0x000001a3afb2f000 nid=0x1674 runnable  [0x0000008ea45fe000]
  242.    java.lang.Thread.State: RUNNABLE
  243.         at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(java.base@10.0.1/Native Method)
  244.         at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(java.base@10.0.1/WindowsSelectorImpl.java:296)
  245.         at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(java.base@10.0.1/WindowsSelectorImpl.java:278)
  246.         at sun.nio.ch.WindowsSelectorImpl.doSelect(java.base@10.0.1/WindowsSelectorImpl.java:159)
  247.         at sun.nio.ch.SelectorImpl.lockAndDoSelect(java.base@10.0.1/SelectorImpl.java:89)
  248.         - locked <0x00000000d4e620c8> (a io.netty.channel.nio.SelectedSelectionKeySet)
  249.         - locked <0x00000000d4e620e0> (a java.util.Collections$UnmodifiableSet)
  250.         - locked <0x00000000d4e62048> (a sun.nio.ch.WindowsSelectorImpl)
  251.         at sun.nio.ch.SelectorImpl.select(java.base@10.0.1/SelectorImpl.java:100)
  252.         at io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62)
  253.         at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:752)
  254.         at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:408)
  255.         at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
  256.         at java.lang.Thread.run(java.base@10.0.1/Thread.java:844)
  258.    Locked ownable synchronizers:
  259.         - None
  261. "DestroyJavaVM" #15 prio=5 os_prio=0 tid=0x000001a38ff10000 nid=0x2278 waiting on condition  [0x0000000000000000]
  262.    java.lang.Thread.State: RUNNABLE
  264.    Locked ownable synchronizers:
  265.         - None
  267. "NettythreadDeathWatcher-2-1" #17 daemon prio=1 os_prio=-2 tid=0x000001a3b0cb0800 nid=0x2740 waiting on condition  [0x0000008ea48fe000]
  268.    java.lang.Thread.State: TIMED_WAITING (sleeping)
  269.         at java.lang.Thread.sleep(java.base@10.0.1/Native Method)
  270.         at io.netty.util.ThreadDeathWatcher$Watcher.run(ThreadDeathWatcher.java:152)
  271.         at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
  272.         at java.lang.Thread.run(java.base@10.0.1/Thread.java:844)
  274.    Locked ownable synchronizers:
  275.         - None
  276. "VM Thread" os_prio=2 tid=0x000001a3aea31800 nid=0x1de0 runnable
  278. "GC Thread#0" os_prio=2 tid=0x000001a38ff2c000 nid=0x9c8 runnable
  280. "GC Thread#1" os_prio=2 tid=0x000001a38ff2d800 nid=0x410 runnable
  282. "GC Thread#2" os_prio=2 tid=0x000001a38ff30000 nid=0x28e4 runnable
  284. "GC Thread#3" os_prio=2 tid=0x000001a38ff33800 nid=0x22a0 runnable
  286. "GC Thread#4" os_prio=2 tid=0x000001a38ff35800 nid=0x16e4 runnable
  288. "GC Thread#5" os_prio=2 tid=0x000001a38ff3a800 nid=0xfd8 runnable
  290. "GC Thread#6" os_prio=2 tid=0x000001a38ff3e000 nid=0x21a0 runnable
  292. "GC Thread#7" os_prio=2 tid=0x000001a38ff3f000 nid=0x1b88 runnable
  294. "G1 Main Marker" os_prio=2 tid=0x000001a38ff7e800 nid=0x2cd4 runnable
  296. "G1 Conc#0" os_prio=2 tid=0x000001a38ff81800 nid=0xe1c runnable
  298. "G1 Conc#1" os_prio=2 tid=0x000001a38ff82800 nid=0x91c runnable
  300. "G1 Refine#0" os_prio=2 tid=0x000001a38ffde800 nid=0x3350 runnable
  302. "G1 Refine#1" os_prio=2 tid=0x000001a3ae8ce000 nid=0x2d74 runnable
  304. "G1 Refine#2" os_prio=2 tid=0x000001a3ae8d0000 nid=0x59c runnable
  306. "G1 Refine#3" os_prio=2 tid=0x000001a3ae8d0800 nid=0x2f50 runnable
  308. "G1 Refine#4" os_prio=2 tid=0x000001a3ae8d5800 nid=0x2750 runnable
  310. "G1 Refine#5" os_prio=2 tid=0x000001a3ae8d8800 nid=0xa18 runnable
  312. "G1 Refine#6" os_prio=2 tid=0x000001a3ae8db000 nid=0x1c04 runnable
  314. "G1 Refine#7" os_prio=2 tid=0x000001a3ae8ec000 nid=0x3220 runnable
  316. "G1 Young RemSet Sampling" os_prio=2 tid=0x000001a3ae8ec800 nid=0x23cc runnable
  317. "VM Periodic Task Thread" os_prio=2 tid=0x000001a3af485000 nid=0x1540 waiting on condition
  319. JNI global references: 14

四、在线分析工具

Java Thread Dump Analyzer

简单Java线程状态介绍

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