Package org.apache.commons.exec

Class ShutdownHookProcessDestroyer

  • All Implemented Interfaces:
    java.lang.Runnable, ProcessDestroyer
    public class ShutdownHookProcessDestroyer
extends java.lang.Object
implements ProcessDestroyer, java.lang.Runnable
    Destroys all registered Processes when the VM exits.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.util.concurrent.atomic.AtomicBoolean added
      Whether or not this ProcessDestroyer has been registered as a shutdown hook.
      private ShutdownHookProcessDestroyer.ProcessDestroyerThread destroyProcessThread
      The thread registered at the JVM to execute the shutdown handler.
      private java.util.List<java.lang.Process> processes
      The list of currently running processes.
      private java.util.concurrent.atomic.AtomicBoolean running
      Whether or not this ProcessDestroyer is currently running as shutdown hook.

    • Constructor Summary

      Constructors 
      Constructor Description
      ShutdownHookProcessDestroyer()
      Constructs a ProcessDestroyer and obtains Runtime.addShutdownHook() and Runtime.removeShutdownHook() through reflection.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean add​(java.lang.Process process)
      Returns true if the specified Process was successfully added to the list of processes to destroy upon VM exit.
      private void addShutdownHook()
      Registers this ProcessDestroyer as a shutdown hook.
      boolean isAddedAsShutdownHook()
      Tests whether or not the ProcessDestroyer is registered as shutdown hook.
      boolean isEmpty()
      Tests emptiness (size == 0).
      boolean remove​(java.lang.Process process)
      Returns true if the specified Process was successfully removed from the list of processes to destroy upon VM exit.
      private void removeShutdownHook()
      Removes this ProcessDestroyer as a shutdown hook.
      void run()
      Invoked by the VM when it is exiting.
      int size()
      Returns the number of registered processes.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • processes

        private final java.util.List<java.lang.Process> processes
        The list of currently running processes.

      • added

        private final java.util.concurrent.atomic.AtomicBoolean added
        Whether or not this ProcessDestroyer has been registered as a shutdown hook.

      • running

        private final java.util.concurrent.atomic.AtomicBoolean running
        Whether or not this ProcessDestroyer is currently running as shutdown hook.

    • Constructor Detail

      • ShutdownHookProcessDestroyer

        public ShutdownHookProcessDestroyer()
        Constructs a ProcessDestroyer and obtains Runtime.addShutdownHook() and Runtime.removeShutdownHook() through reflection. The ProcessDestroyer manages a list of processes to be destroyed when the VM exits. If a process is added when the list is empty, this ProcessDestroyer is registered as a shutdown hook. If removing a process results in an empty list, the ProcessDestroyer is removed as a shutdown hook.

    • Method Detail

      • add

        public boolean add​(java.lang.Process process)
        Returns true if the specified Process was successfully added to the list of processes to destroy upon VM exit.
        Specified by:
        add in interface ProcessDestroyer
        Parameters:
        process - the process to add.
        Returns:
        true if the specified Process was successfully added.

      • addShutdownHook

        private void addShutdownHook()
        Registers this ProcessDestroyer as a shutdown hook.

      • isAddedAsShutdownHook

        public boolean isAddedAsShutdownHook()
        Tests whether or not the ProcessDestroyer is registered as shutdown hook.
        Returns:
        true if this is currently added as shutdown hook.

      • isEmpty

        public boolean isEmpty()
        Tests emptiness (size == 0).
        Returns:
        Whether or not this is empty.
        Since:
        1.4.0

      • remove

        public boolean remove​(java.lang.Process process)
        Returns true if the specified Process was successfully removed from the list of processes to destroy upon VM exit.
        Specified by:
        remove in interface ProcessDestroyer
        Parameters:
        process - the process to remove.
        Returns:
        true if the specified Process was successfully removed.

      • removeShutdownHook

        private void removeShutdownHook()
        Removes this ProcessDestroyer as a shutdown hook.

      • run

        public void run()
        Invoked by the VM when it is exiting.
        Specified by:
        run in interface java.lang.Runnable

      • size

        public int size()
        Returns the number of registered processes.
        Specified by:
        size in interface ProcessDestroyer
        Returns:
        the number of register process.