Class: java.lang.Thread

  • public class Thread
  • 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.

Every thread has a priority. Threads with higher priority are executed in preference to threads with lower priority. Each thread may or may not also be marked as a daemon. When code running in some thread creates a new Thread object, the new thread has its priority initially set equal to the priority of the creating thread, and is a daemon thread if and only if the creating thread is a daemon.

When a Java Virtual Machine starts up, there is usually a single non-daemon thread (which typically calls the method named main of some designated class). The Java Virtual Machine continues to execute threads until either of the following occurs:

  • The exit method of class Runtime has been called and the security manager has permitted the exit operation to take place.
  • All threads that are not daemon threads have died, either by returning from the call to the run method or by throwing an exception that propagates beyond the run method.

There are two ways to create a new thread of execution. One is to declare a class to be a subclass of Thread. This subclass should override the run method of class Thread. An instance of the subclass can then be allocated and started. For example, a thread that computes primes larger than a stated value could be written as follows: 

     class PrimeThread extends Thread {
         long minPrime;
         PrimeThread(long minPrime) {
             this.minPrime = minPrime;
         }

         public void run() {
             // compute primes larger than minPrime
              . . .
         }
     }

The following code would then create a thread and start it running: 

     PrimeThread p = new PrimeThread(143);
     p.start();

The other way to create a thread is to declare a class that implements the Runnable interface. That class then implements the run method. An instance of the class can then be allocated, passed as an argument when creating Thread, and started. The same example in this other style looks like the following: 

     class PrimeRun implements Runnable {
         long minPrime;
         PrimeRun(long minPrime) {
             this.minPrime = minPrime;
         }

         public void run() {
             // compute primes larger than minPrime
              . . .
         }
     }

The following code would then create a thread and start it running: 

     PrimeRun p = new PrimeRun(143);
     new Thread(p).start();

Every thread has a name for identification purposes. More than one thread may have the same name. If a name is not specified when a thread is created, a new name is generated for it.

Authors:
@author unascribed
See:
@see Runnable
@see Runtime.exit(int)
@see Thread.run()
@see Thread.stop()
Since:
@since JDK1.0

Inheritance

Superclass tree: Implements:

Methods

  • Threadtop

    public Thread()
    Allocates a new Thread object. This constructor has the same effect as Thread(null, null, gname), where gname is a newly generated name. Automatically generated names are of the form "Thread-"+n, where n is an integer.
    See:
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
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  • Threadtop

    public Thread(Runnable target)
    Allocates a new Thread object. This constructor has the same effect as Thread(null, target, gname), where gname is a newly generated name. Automatically generated names are of the form "Thread-"+n, where n is an integer.
    Parameters:
    @param target the object whose run method is called.
    See:
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
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  • Threadtop

    public Thread(Runnable target, String name)
    Allocates a new Thread object. This constructor has the same effect as Thread(null, target, name).
    Parameters:
    @param target the object whose run method is called.
    @param name the name of the new thread.
    See:
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
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  • Threadtop

    public Thread(String name)
    Allocates a new Thread object. This constructor has the same effect as Thread(null, null, name).
    Parameters:
    @param name the name of the new thread.
    See:
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
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  • Threadtop

    public Thread(ThreadGroup group, Runnable target)
    Allocates a new Thread object. This constructor has the same effect as Thread(group, target, gname), where gname is a newly generated name. Automatically generated names are of the form "Thread-"+n, where n is an integer.
    Parameters:
    @param group the thread group.
    @param target the object whose run method is called.
    Exceptions:
    @exception SecurityException if the current thread cannot create a thread in the specified thread group.
    See:
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
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  • Threadtop

    public Thread(ThreadGroup group, Runnable target, String name)
    Allocates a new Thread object so that it has target as its run object, has the specified name as its name, and belongs to the thread group referred to by group.

    If group is null and there is a security manager, the group is determined by the security manager's getThreadGroup method. If group is null and there is not a security manager, or the security manager's getThreadGroup method returns null, the group is set to be the same ThreadGroup as the thread that is creating the new thread.

    If there is a security manager, its checkAccess method is called with the ThreadGroup as its argument.

    In addition, its checkPermission method is called with the RuntimePermission("enableContextClassLoaderOverride") permission when invoked directly or indirectly by the constructor of a subclass which overrides the getContextClassLoader or setContextClassLoader methods. This may result in a SecurityException.

    If the target argument is not null, the run method of the target is called when this thread is started. If the target argument is null, this thread's run method is called when this thread is started.

    The priority of the newly created thread is set equal to the priority of the thread creating it, that is, the currently running thread. The method setPriority may be used to change the priority to a new value.

    The newly created thread is initially marked as being a daemon thread if and only if the thread creating it is currently marked as a daemon thread. The method setDaemon may be used to change whether or not a thread is a daemon.

    Parameters:
    @param group the thread group.
    @param target the object whose run method is called.
    @param name the name of the new thread.
    Exceptions:
    @exception SecurityException if the current thread cannot create a thread in the specified thread group or cannot override the context class loader methods.
    See:
    @see Runnable.run()
    @see Thread.run()
    @see Thread.setDaemon(boolean)
    @see Thread.setPriority(int)
    @see ThreadGroup.checkAccess()
    @see SecurityManager.checkAccess(java.lang.Thread)
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  • Threadtop

    public Thread(ThreadGroup group, Runnable target, String name, long stackSize)
    Allocates a new Thread object so that it has target as its run object, has the specified name as its name, belongs to the thread group referred to by group, and has the specified stack size.

    This constructor is identical to Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String) with the exception of the fact that it allows the thread stack size to be specified. The stack size is the approximate number of bytes of address space that the virtual machine is to allocate for this thread's stack. The effect of the stackSize parameter, if any, is highly platform dependent.

    On some platforms, specifying a higher value for the stackSize parameter may allow a thread to achieve greater recursion depth before throwing a StackOverflowError. Similarly, specifying a lower value may allow a greater number of threads to exist concurrently without throwing an OutOfMemoryError (or other internal error). The details of the relationship between the value of the stackSize parameter and the maximum recursion depth and concurrency level are platform-dependent. On some platforms, the value of the stackSize parameter may have no effect whatsoever.

    The virtual machine is free to treat the stackSize parameter as a suggestion. If the specified value is unreasonably low for the platform, the virtual machine may instead use some platform-specific minimum value; if the specified value is unreasonably high, the virtual machine may instead use some platform-specific maximum. Likewise, the virtual machine is free to round the specified value up or down as it sees fit (or to ignore it completely).

    Specifying a value of zero for the stackSize parameter will cause this constructor to behave exactly like the Thread(ThreadGroup, Runnable, String) constructor.

    Due to the platform-dependent nature of the behavior of this constructor, extreme care should be exercised in its use. The thread stack size necessary to perform a given computation will likely vary from one JRE implementation to another. In light of this variation, careful tuning of the stack size parameter may be required, and the tuning may need to be repeated for each JRE implementation on which an application is to run.

    Implementation note: Java platform implementers are encouraged to document their implementation's behavior with respect to the stackSize parameter.

    Parameters:
    @param group the thread group.
    @param target the object whose run method is called.
    @param name the name of the new thread.
    @param stackSize the desired stack size for the new thread, or zero to indicate that this parameter is to be ignored.
    Exceptions:
    @exception SecurityException if the current thread cannot create a thread in the specified thread group.
    Since:
    @since 1.4
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  • Threadtop

    public Thread(ThreadGroup group, String name)
    Allocates a new Thread object. This constructor has the same effect as Thread(group, null, name)
    Parameters:
    @param group the thread group.
    @param name the name of the new thread.
    Exceptions:
    @exception SecurityException if the current thread cannot create a thread in the specified thread group.
    See:
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
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  • activeCounttop

    public static int activeCount()
    Returns the number of active threads in the current thread's thread group.
    Return:
    @return the number of active threads in the current thread's thread group.
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  • checkAccesstop

    public final void checkAccess()
    Determines if the currently running thread has permission to modify this thread.

    If there is a security manager, its checkAccess method is called with this thread as its argument. This may result in throwing a SecurityException.

    Exceptions:
    @exception SecurityException if the current thread is not allowed to access this thread.
    See:
    @see SecurityManager.checkAccess(java.lang.Thread)
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  • countStackFramestop

    public native int countStackFrames()
    Counts the number of stack frames in this thread. The thread must be suspended.
    Return:
    @return the number of stack frames in this thread.
    Exceptions:
    @exception IllegalThreadStateException if this thread is not suspended.
    Deprecated:
    @deprecated The definition of this call depends on Thread.suspend() , which is deprecated. Further, the results of this call were never well-defined.
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  • currentThreadtop

    public static native Thread currentThread()
    Returns a reference to the currently executing thread object.
    Return:
    @return the currently executing thread.
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  • destroytop

    public void destroy()
    Throws NoSuchMethodError.
    Exceptions:
    @throws NoSuchMethodError always
    Deprecated:
    @deprecated This method was originally designed to destroy this thread without any cleanup. Any monitors it held would have remained locked. However, the method was never implemented. If if were to be implemented, it would be deadlock-prone in much the manner of Thread.suspend() . If the target thread held a lock protecting a critical system resource when it was destroyed, no thread could ever access this resource again. If another thread ever attempted to lock this resource, deadlock would result. Such deadlocks typically manifest themselves as "frozen" processes. For more information, see Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
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  • dumpStacktop

    public static void dumpStack()
    Prints a stack trace of the current thread to the standard error stream. This method is used only for debugging.
    See:
    @see Throwable.printStackTrace()
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  • enumeratetop

    public static int enumerate(Thread[] tarray)
    Copies into the specified array every active thread in the current thread's thread group and its subgroups. This method simply calls the enumerate method of the current thread's thread group with the array argument.

    First, if there is a security manager, that enumerate method calls the security manager's checkAccess method with the thread group as its argument. This may result in throwing a SecurityException.

    Parameters:
    @param tarray an array of Thread objects to copy to
    Return:
    @return the number of threads put into the array
    Exceptions:
    @exception SecurityException if a security manager exists and its checkAccess method doesn't allow the operation.
    See:
    @see ThreadGroup.enumerate(java.lang.Thread[])
    @see SecurityManager.checkAccess(java.lang.ThreadGroup)
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  • getAllStackTracestop

    public static Map<Thread, StackTraceElement[]> getAllStackTraces()
    Returns a map of stack traces for all live threads. The map keys are threads and each map value is an array of StackTraceElement that represents the stack dump of the corresponding Thread. The returned stack traces are in the format specified for the getStackTrace method.

    The threads may be executing while this method is called. The stack trace of each thread only represents a snapshot and each stack trace may be obtained at different time. A zero-length array will be returned in the map value if the virtual machine has no stack trace information about a thread.

    If there is a security manager, then the security manager's checkPermission method is called with a RuntimePermission("getStackTrace") permission as well as RuntimePermission("modifyThreadGroup") permission to see if it is ok to get the stack trace of all threads.

    Return:
    @return a Map from Thread to an array of StackTraceElement that represents the stack trace of the corresponding thread.
    Exceptions:
    @throws SecurityException if a security manager exists and its checkPermission method doesn't allow getting the stack trace of thread.
    See:
    @see Thread.getStackTrace()
    @see SecurityManager.checkPermission(java.security.Permission)
    @see RuntimePermission
    @see Throwable.getStackTrace()
    Since:
    @since 1.5
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  • getContextClassLoadertop

    public ClassLoader getContextClassLoader()
    Returns the context ClassLoader for this Thread. The context ClassLoader is provided by the creator of the thread for use by code running in this thread when loading classes and resources. If not set, the default is the ClassLoader context of the parent Thread. The context ClassLoader of the primordial thread is typically set to the class loader used to load the application.

    First, if there is a security manager, and the caller's class loader is not null and the caller's class loader is not the same as or an ancestor of the context class loader for the thread whose context class loader is being requested, then the security manager's checkPermission method is called with a RuntimePermission("getClassLoader") permission to see if it's ok to get the context ClassLoader..

    Return:
    @return the context ClassLoader for this Thread
    Exceptions:
    @throws SecurityException if a security manager exists and its checkPermission method doesn't allow getting the context ClassLoader.
    See:
    @see Thread.setContextClassLoader(java.lang.ClassLoader)
    @see SecurityManager.checkPermission(java.security.Permission)
    @see RuntimePermission
    Since:
    @since 1.2
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  • getDefaultUncaughtExceptionHandlertop

    public static Thread.UncaughtExceptionHandler getDefaultUncaughtExceptionHandler()
    Returns the default handler invoked when a thread abruptly terminates due to an uncaught exception. If the returned value is null, there is no default.
    See:
    @see Thread.setDefaultUncaughtExceptionHandler(java.lang.Thread$UncaughtExceptionHandler)
    Since:
    @since 1.5
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  • getIdtop

    public long getId()
    Returns the identifier of this Thread. The thread ID is a positive long number generated when this thread was created. The thread ID is unique and remains unchanged during its lifetime. When a thread is terminated, this thread ID may be reused.
    Return:
    @return this thread's ID.
    Since:
    @since 1.5
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  • getNametop

    public final String getName()
    Returns this thread's name.
    Return:
    @return this thread's name.
    See:
    @see Thread.setName(java.lang.String)
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  • getPrioritytop

    public final int getPriority()
    Returns this thread's priority.
    Return:
    @return this thread's priority.
    See:
    @see Thread.setPriority(int)
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  • getStackTracetop

    public StackTraceElement[] getStackTrace()
    Returns an array of stack trace elements representing the stack dump of this thread. This method will return a zero-length array if this thread has not started or has terminated. If the returned array is of non-zero length then the first element of the array represents the top of the stack, which is the most recent method invocation in the sequence. The last element of the array represents the bottom of the stack, which is the least recent method invocation in the sequence.

    If there is a security manager, and this thread is not the current thread, then the security manager's checkPermission method is called with a RuntimePermission("getStackTrace") permission to see if it's ok to get the stack trace.

    Some virtual machines may, under some circumstances, omit one or more stack frames from the stack trace. In the extreme case, a virtual machine that has no stack trace information concerning this thread is permitted to return a zero-length array from this method.

    Return:
    @return an array of StackTraceElement, each represents one stack frame.
    Exceptions:
    @throws SecurityException if a security manager exists and its checkPermission method doesn't allow getting the stack trace of thread.
    See:
    @see SecurityManager.checkPermission(java.security.Permission)
    @see RuntimePermission
    @see Throwable.getStackTrace()
    Since:
    @since 1.5
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  • getStatetop

    public Thread.State getState()
    Returns the state of this thread. This method is designed for use in monitoring of the system state, not for synchronization control.
    Return:
    @return this thread's state.
    Since:
    @since 1.5
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  • getThreadGrouptop

    public final ThreadGroup getThreadGroup()
    Returns the thread group to which this thread belongs. This method returns null if this thread has died (been stopped).
    Return:
    @return this thread's thread group.
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  • getUncaughtExceptionHandlertop

    public Thread.UncaughtExceptionHandler getUncaughtExceptionHandler()
    Returns the handler invoked when this thread abruptly terminates due to an uncaught exception. If this thread has not had an uncaught exception handler explicitly set then this thread's ThreadGroup object is returned, unless this thread has terminated, in which case null is returned.
    Since:
    @since 1.5
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  • holdsLocktop

    public static native boolean holdsLock(Object obj)
    Returns true if and only if the current thread holds the monitor lock on the specified object.

    This method is designed to allow a program to assert that the current thread already holds a specified lock: 

         assert Thread.holdsLock(obj);
    Parameters:
    @param obj the object on which to test lock ownership
    Return:
    @return true if the current thread holds the monitor lock on the specified object.
    Exceptions:
    @throws NullPointerException if obj is null
    Since:
    @since 1.4
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  • interrupttop

    public void interrupt()
    Interrupts this thread.

    Unless the current thread is interrupting itself, which is always permitted, the checkAccess method of this thread is invoked, which may cause a SecurityException to be thrown.

    If this thread is blocked in an invocation of the wait(), wait(long), or wait(long, int) methods of the Object class, or of the Thread.join(), Thread.join(long), Thread.join(long, int), Thread.sleep(long), or Thread.sleep(long, int), methods of this class, then its interrupt status will be cleared and it will receive an InterruptedException.

    If this thread is blocked in an I/O operation upon an interruptible channel then the channel will be closed, the thread's interrupt status will be set, and the thread will receive a java.nio.channels.ClosedByInterruptException.

    If this thread is blocked in a java.nio.channels.Selector then the thread's interrupt status will be set and it will return immediately from the selection operation, possibly with a non-zero value, just as if the selector's wakeup method were invoked.

    If none of the previous conditions hold then this thread's interrupt status will be set.

    Interrupting a thread that is not alive need not have any effect.

    Exceptions:
    @throws SecurityException if the current thread cannot modify this thread
    Misc:
    @revised 6.0
    @spec JSR-51
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  • interruptedtop

    public static boolean interrupted()
    Tests whether the current thread has been interrupted. The interrupted status of the thread is cleared by this method. In other words, if this method were to be called twice in succession, the second call would return false (unless the current thread were interrupted again, after the first call had cleared its interrupted status and before the second call had examined it).

    A thread interruption ignored because a thread was not alive at the time of the interrupt will be reflected by this method returning false.

    Return:
    @return true if the current thread has been interrupted; false otherwise.
    See:
    @see Thread.isInterrupted()
    Misc:
    @revised 6.0
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  • isAlivetop

    public final native boolean isAlive()
    Tests if this thread is alive. A thread is alive if it has been started and has not yet died.
    Return:
    @return true if this thread is alive; false otherwise.
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  • isDaemontop

    public final boolean isDaemon()
    Tests if this thread is a daemon thread.
    Return:
    @return true if this thread is a daemon thread; false otherwise.
    See:
    @see Thread.setDaemon(boolean)
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  • isInterruptedtop

    public boolean isInterrupted()
    Tests whether this thread has been interrupted. The interrupted status of the thread is unaffected by this method.

    A thread interruption ignored because a thread was not alive at the time of the interrupt will be reflected by this method returning false.

    Return:
    @return true if this thread has been interrupted; false otherwise.
    See:
    @see Thread.interrupted()
    Misc:
    @revised 6.0
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  • jointop

    public final void join() throws InterruptedException
    Waits for this thread to die.
    Exceptions:
    @exception InterruptedException if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.
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  • jointop

    public final synchronized void join(long millis) throws InterruptedException
    Waits at most millis milliseconds for this thread to die. A timeout of 0 means to wait forever.
    Parameters:
    @param millis the time to wait in milliseconds.
    Exceptions:
    @exception InterruptedException if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.
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  • jointop

    public final synchronized void join(long millis, int nanos) throws InterruptedException
    Waits at most millis milliseconds plus nanos nanoseconds for this thread to die.
    Parameters:
    @param millis the time to wait in milliseconds.
    @param nanos 0-999999 additional nanoseconds to wait.
    Exceptions:
    @exception IllegalArgumentException if the value of millis is negative the value of nanos is not in the range 0-999999.
    @exception InterruptedException if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.
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  • resumetop

    public final void resume()
    Resumes a suspended thread.

    First, the checkAccess method of this thread is called with no arguments. This may result in throwing a SecurityException (in the current thread).

    If the thread is alive but suspended, it is resumed and is permitted to make progress in its execution.

    Exceptions:
    @exception SecurityException if the current thread cannot modify this thread.
    Deprecated:
    @deprecated This method exists solely for use with Thread.suspend() , which has been deprecated because it is deadlock-prone. For more information, see Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
    See:
    @see Thread.checkAccess()
    @see Thread.suspend()
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  • runtop

    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.

    See:
    @see Thread.start()
    @see Thread.stop()
    @see Thread.Thread(java.lang.ThreadGroup, java.lang.Runnable, java.lang.String)
    Specified by:
    run from Runnable
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  • setContextClassLoadertop

    public void setContextClassLoader(ClassLoader cl)
    Sets the context ClassLoader for this Thread. The context ClassLoader can be set when a thread is created, and allows the creator of the thread to provide the appropriate class loader to code running in the thread when loading classes and resources.

    First, if there is a security manager, its checkPermission method is called with a RuntimePermission("setContextClassLoader") permission to see if it's ok to set the context ClassLoader..

    Parameters:
    @param cl the context ClassLoader for this Thread
    Exceptions:
    @exception SecurityException if the current thread cannot set the context ClassLoader.
    See:
    @see Thread.getContextClassLoader()
    @see SecurityManager.checkPermission(java.security.Permission)
    @see RuntimePermission
    Since:
    @since 1.2
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  • setDaemontop

    public final void setDaemon(boolean on)
    Marks this thread as either a daemon thread or a user thread. The Java Virtual Machine exits when the only threads running are all daemon threads.

    This method must be called before the thread is started.

    This method first calls the checkAccess method of this thread with no arguments. This may result in throwing a SecurityException (in the current thread).

    Parameters:
    @param on if true, marks this thread as a daemon thread.
    Exceptions:
    @exception IllegalThreadStateException if this thread is active.
    @exception SecurityException if the current thread cannot modify this thread.
    See:
    @see Thread.isDaemon()
    @see Thread.checkAccess()
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  • setDefaultUncaughtExceptionHandlertop

    public static void setDefaultUncaughtExceptionHandler(Thread.UncaughtExceptionHandler eh)
    Set the default handler invoked when a thread abruptly terminates due to an uncaught exception, and no other handler has been defined for that thread.

    Uncaught exception handling is controlled first by the thread, then by the thread's ThreadGroup object and finally by the default uncaught exception handler. If the thread does not have an explicit uncaught exception handler set, and the thread's thread group (including parent thread groups) does not specialize its uncaughtException method, then the default handler's uncaughtException method will be invoked.

    By setting the default uncaught exception handler, an application can change the way in which uncaught exceptions are handled (such as logging to a specific device, or file) for those threads that would already accept whatever "default" behavior the system provided.

    Note that the default uncaught exception handler should not usually defer to the thread's ThreadGroup object, as that could cause infinite recursion.

    Parameters:
    @param eh the object to use as the default uncaught exception handler. If null then there is no default handler.
    Exceptions:
    @throws SecurityException if a security manager is present and it denies RuntimePermission ("setDefaultUncaughtExceptionHandler")
    See:
    @see Thread.setUncaughtExceptionHandler(java.lang.Thread$UncaughtExceptionHandler)
    @see Thread.getUncaughtExceptionHandler()
    @see ThreadGroup.uncaughtException(java.lang.Thread, java.lang.Throwable)
    Since:
    @since 1.5
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  • setNametop

    public final void setName(String name)
    Changes the name of this thread to be equal to the argument name.

    First the checkAccess method of this thread is called with no arguments. This may result in throwing a SecurityException.

    Parameters:
    @param name the new name for this thread.
    Exceptions:
    @exception SecurityException if the current thread cannot modify this thread.
    See:
    @see Thread.getName()
    @see Thread.checkAccess()
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  • setPrioritytop

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

    First the checkAccess method of this thread is called with no arguments. This may result in throwing a SecurityException.

    Otherwise, the priority of this thread is set to the smaller of the specified newPriority and the maximum permitted priority of the thread's thread group.

    Parameters:
    @param newPriority priority to set this thread to
    Exceptions:
    @exception IllegalArgumentException If the priority is not in the range MIN_PRIORITY to MAX_PRIORITY.
    @exception SecurityException if the current thread cannot modify this thread.
    See:
    @see Thread.getPriority()
    @see Thread.checkAccess()
    @see Thread.getThreadGroup()
    @see Thread.MAX_PRIORITY
    @see Thread.MIN_PRIORITY
    @see ThreadGroup.getMaxPriority()
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  • setUncaughtExceptionHandlertop

    public void setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler eh)
    Set the handler invoked when this thread abruptly terminates due to an uncaught exception.

    A thread can take full control of how it responds to uncaught exceptions by having its uncaught exception handler explicitly set. If no such handler is set then the thread's ThreadGroup object acts as its handler.

    Parameters:
    @param eh the object to use as this thread's uncaught exception handler. If null then this thread has no explicit handler.
    Exceptions:
    @throws SecurityException if the current thread is not allowed to modify this thread.
    See:
    @see Thread.setDefaultUncaughtExceptionHandler(java.lang.Thread$UncaughtExceptionHandler)
    @see ThreadGroup.uncaughtException(java.lang.Thread, java.lang.Throwable)
    Since:
    @since 1.5
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  • sleeptop

    public static native void sleep(long millis) throws InterruptedException
    Causes the currently executing thread to sleep (temporarily cease execution) for the specified number of milliseconds, subject to the precision and accuracy of system timers and schedulers. The thread does not lose ownership of any monitors.
    Parameters:
    @param millis the length of time to sleep in milliseconds.
    Exceptions:
    @exception InterruptedException if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.
    See:
    @see Object.notify()
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  • sleeptop

    public static void sleep(long millis, int nanos) throws InterruptedException
    Causes the currently executing thread to sleep (cease execution) for the specified number of milliseconds plus the specified number of nanoseconds, subject to the precision and accuracy of system timers and schedulers. The thread does not lose ownership of any monitors.
    Parameters:
    @param millis the length of time to sleep in milliseconds.
    @param nanos 0-999999 additional nanoseconds to sleep.
    Exceptions:
    @exception IllegalArgumentException if the value of millis is negative or the value of nanos is not in the range 0-999999.
    @exception InterruptedException if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.
    See:
    @see Object.notify()
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  • starttop

    public synchronized 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).

    It is never legal to start a thread more than once. In particular, a thread may not be restarted once it has completed execution.

    Exceptions:
    @exception IllegalThreadStateException if the thread was already started.
    See:
    @see Thread.run()
    @see Thread.stop()
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  • stoptop

    public final void stop()
    Forces the thread to stop executing.

    If there is a security manager installed, its checkAccess method is called with this as its argument. This may result in a SecurityException being raised (in the current thread).

    If this thread is different from the current thread (that is, the current thread is trying to stop a thread other than itself), the security manager's checkPermission method (with a RuntimePermission("stopThread") argument) is called in addition. Again, this may result in throwing a SecurityException (in the current thread).

    The thread represented by this thread is forced to stop whatever it is doing abnormally and to throw a newly created ThreadDeath object as an exception.

    It is permitted to stop a thread that has not yet been started. If the thread is eventually started, it immediately terminates.

    An application should not normally try to catch ThreadDeath unless it must do some extraordinary cleanup operation (note that the throwing of ThreadDeath causes finally clauses of try statements to be executed before the thread officially dies). If a catch clause catches a ThreadDeath object, it is important to rethrow the object so that the thread actually dies.

    The top-level error handler that reacts to otherwise uncaught exceptions does not print out a message or otherwise notify the application if the uncaught exception is an instance of ThreadDeath.

    Exceptions:
    @exception SecurityException if the current thread cannot modify this thread.
    Deprecated:
    @deprecated This method is inherently unsafe. Stopping a thread with Thread.stop causes it to unlock all of the monitors that it has locked (as a natural consequence of the unchecked ThreadDeath exception propagating up the stack). If any of the objects previously protected by these monitors were in an inconsistent state, the damaged objects become visible to other threads, potentially resulting in arbitrary behavior. Many uses of stop should be replaced by code that simply modifies some variable to indicate that the target thread should stop running. The target thread should check this variable regularly, and return from its run method in an orderly fashion if the variable indicates that it is to stop running. If the target thread waits for long periods (on a condition variable, for example), the interrupt method should be used to interrupt the wait. For more information, see Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
    See:
    @see Thread.interrupt()
    @see Thread.checkAccess()
    @see Thread.run()
    @see Thread.start()
    @see ThreadDeath
    @see ThreadGroup.uncaughtException(java.lang.Thread, java.lang.Throwable)
    @see SecurityManager.checkAccess(java.lang.Thread)
    @see SecurityManager.checkPermission(java.security.Permission)
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  • stoptop

    public final synchronized void stop(Throwable obj)
    Forces the thread to stop executing.

    If there is a security manager installed, the checkAccess method of this thread is called, which may result in a SecurityException being raised (in the current thread).

    If this thread is different from the current thread (that is, the current thread is trying to stop a thread other than itself) or obj is not an instance of ThreadDeath, the security manager's checkPermission method (with the RuntimePermission("stopThread") argument) is called in addition. Again, this may result in throwing a SecurityException (in the current thread).

    If the argument obj is null, a NullPointerException is thrown (in the current thread).

    The thread represented by this thread is forced to stop whatever it is doing abnormally and to throw the Throwable object obj as an exception. This is an unusual action to take; normally, the stop method that takes no arguments should be used.

    It is permitted to stop a thread that has not yet been started. If the thread is eventually started, it immediately terminates.

    Parameters:
    @param obj the Throwable object to be thrown.
    Exceptions:
    @exception SecurityException if the current thread cannot modify this thread.
    @throws NullPointerException if obj is null.
    Deprecated:
    @deprecated This method is inherently unsafe. See Thread.stop() for details. An additional danger of this method is that it may be used to generate exceptions that the target thread is unprepared to handle (including checked exceptions that the thread could not possibly throw, were it not for this method). For more information, see Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
    See:
    @see Thread.interrupt()
    @see Thread.checkAccess()
    @see Thread.run()
    @see Thread.start()
    @see Thread.stop()
    @see SecurityManager.checkAccess(java.lang.Thread)
    @see SecurityManager.checkPermission(java.security.Permission)
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  • suspendtop

    public final void suspend()
    Suspends this thread.

    First, the checkAccess method of this thread is called with no arguments. This may result in throwing a SecurityException (in the current thread).

    If the thread is alive, it is suspended and makes no further progress unless and until it is resumed.

    Exceptions:
    @exception SecurityException if the current thread cannot modify this thread.
    Deprecated:
    @deprecated This method has been deprecated, as it is inherently deadlock-prone. If the target thread holds a lock on the monitor protecting a critical system resource when it is suspended, no thread can access this resource until the target thread is resumed. If the thread that would resume the target thread attempts to lock this monitor prior to calling resume, deadlock results. Such deadlocks typically manifest themselves as "frozen" processes. For more information, see Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
    See:
    @see Thread.checkAccess()
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  • toStringtop

    public String toString()
    Returns a string representation of this thread, including the thread's name, priority, and thread group.
    Return:
    @return a string representation of this thread.
    Override hierarchy:
    toString from Object
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  • yieldtop

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

  • MAX_PRIORITY

    public static final int MAX_PRIORITY = 10
    The maximum priority that a thread can have.

  • MIN_PRIORITY

    public static final int MIN_PRIORITY = 1
    The minimum priority that a thread can have.

  • NORM_PRIORITY

    public static final int NORM_PRIORITY = 5
    The default priority that is assigned to a thread.