Class Thread

java.lang.Object
java.lang.Thread
All Implemented Interfaces:
Runnable
public class Thread extends Object implements Runnable
A thread is a thread of execution in a program. The Java Virtual Machine allows an application to have multiple threads of execution running concurrently.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    Thread.UncaughtExceptionHandler
    Handles what a thread's run method throws.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    MAX_PRIORITY
    The maximum priority that a thread can have.
    static final int
    MIN_PRIORITY
    The minimum priority that a thread can have.
    static final int
    NORM_PRIORITY
    The default priority that is assigned to a thread.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Thread()
    Allocates a new Thread object.
    Thread(Runnable target)
    Allocates a new Thread object with a specific target object whose run method is called.
    Thread(Runnable target, String name)
    Allocates a new Thread object with the given target and name.
    Thread(String name)
    Allocates a new Thread object with the given name.

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    activeCount()
    Returns the current number of active threads in the virtual machine.
    static Thread
    currentThread()
    Returns a reference to the currently executing Thread object.
    static Thread.UncaughtExceptionHandler
    getDefaultUncaughtExceptionHandler()
    The handler setDefaultUncaughtExceptionHandler set, or null.
    long
    getId()
    A number that identifies this thread for its lifetime.
    final String
    getName()
    Returns this thread's name.
    final int
    getPriority()
    Returns this thread's priority.
    StackTraceElement[]
    getStackTrace()
     
    Thread.UncaughtExceptionHandler
    getUncaughtExceptionHandler()
    This thread's handler, or the default handler when it has none.
    void
    interrupt()
    Interrupts this thread.
    static boolean
    interrupted()
    Tests and clears the current thread's interrupt status.
    final boolean
    isAlive()
    Tests if this thread is alive.
    final boolean
    isDaemon()
    Returns whether this thread is a daemon.
    boolean
    isInterrupted()
    Tests this thread's interrupt status without clearing it.
    final void
    join()
    Waits for this thread to die.
    final void
    join(long millis)
    Waits at most millis milliseconds for this thread to die; 0 waits for as long as it takes.
    final void
    join(long millis, int nanos)
    Waits at most millis milliseconds plus nanos nanoseconds for this thread to die.
    void
    run()
    If this thread was constructed using a separate Runnable run object, then that Runnable object's run method is called; otherwise, this method does nothing and returns.
    final void
    setDaemon(boolean on)
    Marks this thread as a daemon before it is started.
    static void
    setDefaultUncaughtExceptionHandler(Thread.UncaughtExceptionHandler handler)
    Sets the handler for what any thread without its own handler throws.
    final void
    setName(String name)
    Changes this thread's name.
    final void
    setPriority(int newPriority)
    Changes the priority of this thread.
    void
    setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler handler)
    Sets the handler for what this thread's run method throws; null leaves it to the default handler.
    static void
    sleep(long millis)
    Causes the currently executing thread to sleep (temporarily cease execution) for the specified number of milliseconds.
    static void
    sleep(long millis, int nanos)
    Sleeps for millis milliseconds plus nanos nanoseconds.
    void
    start()
    Causes this thread to begin execution; the Java Virtual Machine calls the run method of this thread.
    String
    toString()
    Returns a string representation of this thread, including the thread's name and priority.
    static void
    yield()
    Causes the currently executing thread object to temporarily pause and allow other threads to execute.

    Methods inherited from class Object

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

  • Field Details

    • MAX_PRIORITY

      public static final int MAX_PRIORITY
      The maximum priority that a thread can have. See Also:Constant Field Values
      See Also:

    • MIN_PRIORITY

      public static final int MIN_PRIORITY
      The minimum priority that a thread can have. See Also:Constant Field Values
      See Also:

    • NORM_PRIORITY

      public static final int NORM_PRIORITY
      The default priority that is assigned to a thread. See Also:Constant Field Values
      See Also:

  • Constructor Details

    • Thread

      public Thread()
      Allocates a new Thread object. Threads created this way must have overridden their run() method to actually do anything.

    • Thread

      public Thread(Runnable target)
      Allocates a new Thread object with a specific target object whose run method is called. target - the object whose run method is called.

    • Thread

      public Thread(Runnable target, String name)
      Allocates a new Thread object with the given target and name. target - the object whose run method is called.name - the name of the new thread.

    • Thread

      public Thread(String name)
      Allocates a new Thread object with the given name. Threads created this way must have overridden their run() method to actually do anything. name - the name of the new thread.

  • Method Details

    • activeCount

      public static int activeCount()
      Returns the current number of active threads in the virtual machine.

    • currentThread

      public static Thread currentThread()
      Returns a reference to the currently executing Thread object.

    • getName

      public final String getName()
      Returns this thread's name. Note that in CLDC the name of the thread can only be set when creating the thread.

    • getPriority

      public final int getPriority()
      Returns this thread's priority.

    • interrupt

      public void interrupt()
      Interrupts this thread. In an implementation conforming to the CLDC Specification, this operation is not required to cancel or clean up any pending I/O operations that the thread may be waiting for.

    • interrupted

      public static boolean interrupted()
      Tests and clears the current thread's interrupt status. Compile-time declaration; each platform supplies the runtime implementation.

    • isInterrupted

      public boolean isInterrupted()
      Tests this thread's interrupt status without clearing it.

    • setDaemon

      public final void setDaemon(boolean on)
      Marks this thread as a daemon before it is started.

    • isDaemon

      public final boolean isDaemon()
      Returns whether this thread is a daemon.

    • isAlive

      public final boolean isAlive()
      Tests if this thread is alive. A thread is alive if it has been started and has not yet died.

    • join

      public final void join() throws InterruptedException
      Waits for this thread to die.
      Throws:
      InterruptedException

    • join

      public final void join(long millis) throws InterruptedException
      Waits at most millis milliseconds for this thread to die; 0 waits for as long as it takes.
      Throws:
      InterruptedException

    • join

      public final void join(long millis, int nanos) throws InterruptedException
      Waits at most millis milliseconds plus nanos nanoseconds for this thread to die.
      Throws:
      InterruptedException

    • sleep

      public static void sleep(long millis, int nanos) throws InterruptedException
      Sleeps for millis milliseconds plus nanos nanoseconds.
      Throws:
      InterruptedException

    • setName

      public final void setName(String name)
      Changes this thread's name.

    • getId

      public long getId()
      A number that identifies this thread for its lifetime.

    • setUncaughtExceptionHandler

      public void setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler handler)
      Sets the handler for what this thread's run method throws; null leaves it to the default handler.

    • getUncaughtExceptionHandler

      public Thread.UncaughtExceptionHandler getUncaughtExceptionHandler()
      This thread's handler, or the default handler when it has none.

    • setDefaultUncaughtExceptionHandler

      public static void setDefaultUncaughtExceptionHandler(Thread.UncaughtExceptionHandler handler)
      Sets the handler for what any thread without its own handler throws. In a Codename One application it also receives what an event dispatch thread task throws, which then no longer reaches the platform's own error handling.

    • getDefaultUncaughtExceptionHandler

      public static Thread.UncaughtExceptionHandler getDefaultUncaughtExceptionHandler()
      The handler setDefaultUncaughtExceptionHandler set, or null.

    • run

      public void run()
      If this thread was constructed using a separate Runnable run object, then that Runnable object's run method is called; otherwise, this method does nothing and returns. Subclasses of Thread should override this method.
      Specified by:
      run in interface Runnable

    • setPriority

      public final void setPriority(int newPriority)
      Changes the priority of this thread.

    • sleep

      public static void sleep(long millis) throws InterruptedException
      Causes the currently executing thread to sleep (temporarily cease execution) for the specified number of milliseconds. The thread does not lose ownership of any monitors.
      Throws:
      InterruptedException

    • start

      public void start()
      Causes this thread to begin execution; the Java Virtual Machine calls the run method of this thread. The result is that two threads are running concurrently: the current thread (which returns from the call to the start method) and the other thread (which executes its run method).

    • toString

      public String toString()
      Returns a string representation of this thread, including the thread's name and priority.
      Overrides:
      toString in class Object

    • yield

      public static void yield()
      Causes the currently executing thread object to temporarily pause and allow other threads to execute.

    • getStackTrace

      public StackTraceElement[] getStackTrace()