一、前言

关于alibaba的dubbo源码包com.alibaba.dubbo.common.utils.JVMUtil虚拟机工具类,将线程内部执行过程进行打印输出，详情参见源码说明。

二、源码说明

package dubbo;@b@@b@import java.io.FileOutputStream;@b@import java.io.OutputStream;@b@import java.lang.management.LockInfo;@b@import java.lang.management.ManagementFactory;@b@import java.lang.management.MonitorInfo;@b@import java.lang.management.ThreadInfo;@b@import java.lang.management.ThreadMXBean;@b@@b@public class JVMUtil {@b@	@b@    public static void jstack(OutputStream stream) throws Exception {@b@        ThreadMXBean threadMxBean = ManagementFactory.getThreadMXBean();@b@        for (ThreadInfo threadInfo : threadMxBean.dumpAllThreads(true, true)) {@b@            stream.write(getThreadDumpString(threadInfo).getBytes());@b@        }@b@    }@b@@b@    private static String getThreadDumpString(ThreadInfo threadInfo) {@b@        StringBuilder sb = new StringBuilder("\"" + threadInfo.getThreadName() + "\"" +@b@                " Id=" + threadInfo.getThreadId() + " " +@b@                threadInfo.getThreadState());@b@        if (threadInfo.getLockName() != null) {@b@            sb.append(" on " + threadInfo.getLockName());@b@        }@b@        if (threadInfo.getLockOwnerName() != null) {@b@            sb.append(" owned by \"" + threadInfo.getLockOwnerName() +@b@                    "\" Id=" + threadInfo.getLockOwnerId());@b@        }@b@        if (threadInfo.isSuspended()) {@b@            sb.append(" (suspended)");@b@        }@b@        if (threadInfo.isInNative()) {@b@            sb.append(" (in native)");@b@        }@b@        sb.append('\n');@b@        int i = 0;@b@@b@        StackTraceElement[] stackTrace = threadInfo.getStackTrace();@b@        MonitorInfo[] lockedMonitors = threadInfo.getLockedMonitors();@b@        for (; i < stackTrace.length && i < 32; i++) {@b@            StackTraceElement ste = stackTrace[i];@b@            sb.append("\tat " + ste.toString());@b@            sb.append('\n');@b@            if (i == 0 && threadInfo.getLockInfo() != null) {@b@                Thread.State ts = threadInfo.getThreadState();@b@                switch (ts) {@b@                    case BLOCKED:@b@                        sb.append("\t-  blocked on " + threadInfo.getLockInfo());@b@                        sb.append('\n');@b@                        break;@b@                    case WAITING:@b@                        sb.append("\t-  waiting on " + threadInfo.getLockInfo());@b@                        sb.append('\n');@b@                        break;@b@                    case TIMED_WAITING:@b@                        sb.append("\t-  waiting on " + threadInfo.getLockInfo());@b@                        sb.append('\n');@b@                        break;@b@                    default:@b@                }@b@            }@b@@b@            for (MonitorInfo mi : lockedMonitors) {@b@                if (mi.getLockedStackDepth() == i) {@b@                    sb.append("\t-  locked " + mi);@b@                    sb.append('\n');@b@                }@b@            }@b@        }@b@        if (i < stackTrace.length) {@b@            sb.append("\t...");@b@            sb.append('\n');@b@        }@b@@b@        LockInfo[] locks = threadInfo.getLockedSynchronizers();@b@        if (locks.length > 0) {@b@            sb.append("\n\tNumber of locked synchronizers = " + locks.length);@b@            sb.append('\n');@b@            for (LockInfo li : locks) {@b@                sb.append("\t- " + li);@b@                sb.append('\n');@b@            }@b@        }@b@        sb.append('\n');@b@        return sb.toString();@b@    }@b@    @b@	public static void main(String[] args) throws Exception{@b@		@b@		FileOutputStream  fos=new  FileOutputStream("C:/WS/1.txt");@b@		jstack(fos);@b@	}@b@@b@}

输出的1.txt内容如下

"Attach Listener" Id=5 RUNNABLE "Signal Dispatcher" Id=4 RUNNABLE "Finalizer" Id=3 WAITING on java.lang.ref.ReferenceQueue$Lock@a62fc3@b@@b@	at java.lang.Object.wait(Native Method) -  waiting on java.lang.ref.ReferenceQueue$Lock@a62fc3@b@@b@	at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118)@b@@b@	at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134)@b@@b@	at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:171) "Reference Handler" Id=2 WAITING on java.lang.ref.Reference$Lock@89ae9e@b@	@b@	at java.lang.Object.wait(Native Method) -  waiting on java.lang.ref.Reference$Lock@89ae9e@b@@b@	at java.lang.Object.wait(Object.java:485)@b@@b@	at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116) "main" Id=1 RUNNABLE@b@@b@	at sun.management.ThreadImpl.dumpThreads0(Native Method)@b@@b@	at sun.management.ThreadImpl.dumpAllThreads(ThreadImpl.java:433)@b@@b@	at dubbo.JVMUtil.jstack(JVMUtil.java:15)@b@@b@	at dubbo.JVMUtil.main(JVMUtil.java:93)