Package org.apache.tomcat.util

Class Diagnostics

  • public class Diagnostics
extends java.lang.Object

    • Constructor Summary

      Constructors 
      Constructor Description
      Diagnostics()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.lang.String findDeadlock()
      Check if any threads are deadlocked.
      static void gc()
      Initiate garbage collection via MX Bean
      static java.lang.String getThreadDump()
      Retrieves a formatted JVM thread dump.
      static java.lang.String getThreadDump​(java.util.Enumeration<java.util.Locale> requestedLocales)
      Retrieves a formatted JVM thread dump.
      static java.lang.String getThreadDump​(StringManager requestedSm)
      Retrieve a JVM thread dump formatted using the given StringManager.
      static java.lang.String getVMInfo()
      Retrieves a formatted JVM information text.
      static java.lang.String getVMInfo​(java.util.Enumeration<java.util.Locale> requestedLocales)
      Retrieves a formatted JVM information text.
      static java.lang.String getVMInfo​(StringManager requestedSm)
      Retrieve a JVM information text formatted using the given StringManager.
      static boolean isThreadContentionMonitoringEnabled()
      Check whether thread contention monitoring is enabled.
      static boolean isThreadCpuTimeEnabled()
      Check whether thread cpu time measurement is enabled.
      static void resetPeakThreadCount()
      Reset peak thread count in ThreadMXBean
      static void resetPeakUsage​(java.lang.String name)
      Reset peak memory usage data in MemoryPoolMXBean
      static boolean setCollectionUsageThreshold​(java.lang.String name, long threshold)
      Set collection usage threshold in MemoryPoolMXBean
      static void setLoggerLevel​(java.lang.String loggerName, java.lang.String levelName)
      Set logger level
      static void setThreadContentionMonitoringEnabled​(boolean enable)
      Enable or disable thread contention monitoring via the ThreadMxMXBean.
      static void setThreadCpuTimeEnabled​(boolean enable)
      Enable or disable thread cpu time measurement via the ThreadMxMXBean.
      static boolean setUsageThreshold​(java.lang.String name, long threshold)
      Set usage threshold in MemoryPoolMXBean
      static void setVerboseClassLoading​(boolean verbose)
      Set verbose class loading
      static void setVerboseGarbageCollection​(boolean verbose)
      Set verbose garbage collection logging

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • Diagnostics

        public Diagnostics()

    • Method Detail

      • isThreadContentionMonitoringEnabled

        public static boolean isThreadContentionMonitoringEnabled()
        Check whether thread contention monitoring is enabled.
        Returns:
        true if thread contention monitoring is enabled

      • setThreadContentionMonitoringEnabled

        public static void setThreadContentionMonitoringEnabled​(boolean enable)
        Enable or disable thread contention monitoring via the ThreadMxMXBean.
        Parameters:
        enable - whether to enable thread contention monitoring

      • isThreadCpuTimeEnabled

        public static boolean isThreadCpuTimeEnabled()
        Check whether thread cpu time measurement is enabled.
        Returns:
        true if thread cpu time measurement is enabled

      • setThreadCpuTimeEnabled

        public static void setThreadCpuTimeEnabled​(boolean enable)
        Enable or disable thread cpu time measurement via the ThreadMxMXBean.
        Parameters:
        enable - whether to enable thread cpu time measurement

      • resetPeakThreadCount

        public static void resetPeakThreadCount()
        Reset peak thread count in ThreadMXBean

      • setVerboseClassLoading

        public static void setVerboseClassLoading​(boolean verbose)
        Set verbose class loading
        Parameters:
        verbose - whether to enable verbose class loading

      • setLoggerLevel

        public static void setLoggerLevel​(java.lang.String loggerName,
                                  java.lang.String levelName)
        Set logger level
        Parameters:
        loggerName - the name of the logger
        levelName - the level to set

      • setVerboseGarbageCollection

        public static void setVerboseGarbageCollection​(boolean verbose)
        Set verbose garbage collection logging
        Parameters:
        verbose - whether to enable verbose gc logging

      • gc

        public static void gc()
        Initiate garbage collection via MX Bean

      • resetPeakUsage

        public static void resetPeakUsage​(java.lang.String name)
        Reset peak memory usage data in MemoryPoolMXBean
        Parameters:
        name - name of the MemoryPoolMXBean or "all"

      • setUsageThreshold

        public static boolean setUsageThreshold​(java.lang.String name,
                                        long threshold)
        Set usage threshold in MemoryPoolMXBean
        Parameters:
        name - name of the MemoryPoolMXBean
        threshold - the threshold to set
        Returns:
        true if setting the threshold succeeded

      • setCollectionUsageThreshold

        public static boolean setCollectionUsageThreshold​(java.lang.String name,
                                                  long threshold)
        Set collection usage threshold in MemoryPoolMXBean
        Parameters:
        name - name of the MemoryPoolMXBean
        threshold - the collection threshold to set
        Returns:
        true if setting the threshold succeeded

      • findDeadlock

        public static java.lang.String findDeadlock()
        Check if any threads are deadlocked. If any, print the thread dump for those threads.
        Returns:
        a deadlock message and the formatted thread dump of the deadlocked threads

      • getThreadDump

        public static java.lang.String getThreadDump()
        Retrieves a formatted JVM thread dump. The default StringManager will be used.
        Returns:
        the formatted JVM thread dump

      • getThreadDump

        public static java.lang.String getThreadDump​(java.util.Enumeration<java.util.Locale> requestedLocales)
        Retrieves a formatted JVM thread dump. The given list of locales will be used to retrieve a StringManager.
        Parameters:
        requestedLocales - list of locales to use
        Returns:
        the formatted JVM thread dump

      • getThreadDump

        public static java.lang.String getThreadDump​(StringManager requestedSm)
        Retrieve a JVM thread dump formatted using the given StringManager.
        Parameters:
        requestedSm - the StringManager to use
        Returns:
        the formatted JVM thread dump

      • getVMInfo

        public static java.lang.String getVMInfo()
        Retrieves a formatted JVM information text. The default StringManager will be used.
        Returns:
        the formatted JVM information text

      • getVMInfo

        public static java.lang.String getVMInfo​(java.util.Enumeration<java.util.Locale> requestedLocales)
        Retrieves a formatted JVM information text. The given list of locales will be used to retrieve a StringManager.
        Parameters:
        requestedLocales - list of locales to use
        Returns:
        the formatted JVM information text

      • getVMInfo

        public static java.lang.String getVMInfo​(StringManager requestedSm)
        Retrieve a JVM information text formatted using the given StringManager.
        Parameters:
        requestedSm - the StringManager to use
        Returns:
        the formatted JVM information text