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Class java.lang.Object

java.lang.Object

public class Object

See Also:

Class

Object()

clone()

Creates a clone of the object.

equals(Object)

Compares two Objects for equality.

finalize()

Code to perform when this object is garbage collected.

getClass()

Returns the Class of this Object.

hashCode()

Returns a hashcode for this Object.

notify()

Notifies a single waiting thread on a change in condition of another thread.

notifyAll()

Notifies all of the threads waiting for a condition to change.

toString()

Returns a String that represents the value of this Object.

wait()

Causes a thread to wait forever until it is notified.

wait(long)

Causes a thread to wait until it is notified or the specified timeout expires.

wait(long, int)

More accurate wait.

public Object()

public final Class getClass()

Returns the Class of this Object. Java has a runtime representation for classes- a descriptor of type Class- which the method getClass() returns for any Object.

public int hashCode()

Returns a hashcode for this Object. Each Object in the Java system has a hashcode. The hashcode is a number that is usually different for different Objects. It is used when storing Objects in hashtables. Note: hashcodes can be negative as well as positive.

See Also:

Hashtable

public boolean equals(Object obj)

Compares two Objects for equality. Returns a boolean that indicates whether this Object is equivalent to the specified Object. This method is used when an Object is stored in a hashtable.

Parameters:

obj - the Object to compare with

Returns:

true if these Objects are equal; false otherwise.

See Also:

Hashtable

protected Object clone() throws CloneNotSupportedException

Creates a clone of the object. A new instance is allocated and a bitwise clone of the current object is place in the new object.

Returns:

a clone of this Object.

Throws: OutOfMemoryError

If there is not enough memory.

Throws: CloneNotSupportedException

Object explicitly does not want to be cloned, or it does not support the Cloneable interface.

public String toString()

Returns a String that represents the value of this Object. It is recommended that all subclasses override this method.

public final void notify()

Notifies a single waiting thread on a change in condition of another thread. The thread effecting the change notifies the waiting thread using notify(). Threads that want to wait for a condition to change before proceeding can call wait().

The method notify() can only be called by the thread that is the owner of the current object's monitor.

Throws: IllegalMonitorStateException

If the current thread is not the owner of the Object's monitor.

See Also:

wait, notifyAll

public final void notifyAll()

Notifies all of the threads waiting for a condition to change. Threads that are waiting are generally waiting for another thread to change some condition. Thus, the thread effecting a change that more than one thread is waiting for notifies all the waiting threads using the method notifyAll(). Threads that want to wait for a condition to change before proceeding can call wait().

The method notifyAll() can only be called by the thread that is the owner of the current object's monitor.

Throws: IllegalMonitorStateException

If the current thread is not the owner of the Object's monitor.

See Also:

wait, notify

public final void wait(long timeout) throws InterruptedException

Causes a thread to wait until it is notified or the specified timeout expires.

The method wait() can only be called from within a synchronized method.

Parameters:

timeout - the maximum time to wait in milliseconds

Throws: IllegalMonitorStateException

If the current thread is not the owner of the Object's monitor.

Throws: InterruptedException

Another thread has interrupted this thread.

public final void wait(long timeout,
                         int nanos) throws InterruptedException

More accurate wait. The method wait() can only be called by the thread that is the owner of the current object's monitor.

Parameters:

timeout - the maximum time to wait in milliseconds

nano - additional time, in nanoseconds range 0-999999

Throws: IllegalMonitorStateException

If the current thread is not the owner of the Object's monitor.

Throws: InterruptedException

Another thread has interrupted this thread.

public final void wait() throws InterruptedException

Causes a thread to wait forever until it is notified.

The method wait() can only be called from within a synchronized method

Throws: IllegalMonitorStateException

If the current thread is not the owner of the Object's monitor.

Throws: InterruptedException

Another thread has interrupted this thread.

protected void finalize() throws Throwable

Code to perform when this object is garbage collected. The default is that nothing needs to be performed. Any exception thrown by a finalize method causes the finalization to halt. But otherwise, it is ignored.

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