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java.lang.Object
Object
is the root of the class hierarchy.
Every class has Object
as a superclass. All objects,
including arrays, implement the methods of this class.
public Object()
protected native java.lang.Object clone() throws CloneNotSupportedException
The clone
method of class Object
will
only clone an object whose class indicates that it is willing for
its instances to be cloned. A class indicates that its instances
can be cloned by declaring that it implements the
Cloneable
interface.
Cloneable
interface. Subclasses
that override the clone
method can also
throw this exception to indicate that an instance cannot
be cloned.
public boolean equals(Object obj)
The equals
method implements an equivalence relation:
x
,
x.equals(x)
should return true
.
x
and
y
, x.equals(y)
should return
true
if and only if y.equals(x)
returns
true
.
x
,
y
, and z
, if x.equals(y)
returns true
and y.equals(z)
returns
true
, then x.equals(z)
should return
true
.
x
and y
, multiple invocations of x.equals(y)
consistently return true
or consistently return
false
.
x
, x.equals(null)
should return false
.
The equals method for class Object
implements the most
discriminating possible equivalence relation on objects; that is,
for any reference values x
and y
, this
method returns true
if and only if x
and
y
refer to the same object (x==y
has the
value true
).
true
if this object is the same as the obj
argument; false
otherwise.
protected void finalize() throws Throwable
finalize
method to dispose of
system resources or to perform other cleanup.
Any exception thrown by the finalize
method causes
the finalization of this object to be halted, but is otherwise
ignored.
The finalize
method in Object
does
nothing.
public final native java.lang.Class getClass()
Class
that represents the
runtime class of the object.
public native int hashCode()
java.util.Hashtable
.
The general contract of hashCode
is:
hashCode
method
must consistently return the same integer. This integer need not
remain consistent from one execution of an application to another
execution of the same application.
equals
method, then calling the hashCode
method on each of the
two objects must produce the same integer result.
public final native void notify()
wait
methods.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized
statement
that synchronizes on the object.
Class,
by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
public final native void notifyAll()
wait
methods.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify
method for a
description of the ways in which a thread can become the owner of
a monitor.
public java.lang.String toString()
toString
method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommendedthat all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@
', and
the unsigned hexadecimal representation of the hash code of the
object.
public final native void wait(long timeout) throws InterruptedException
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify
method
or the notifyAll
method.
timeout
argument in milliseconds, has elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify
method for a
description of the ways in which a thread can become the owner of
a monitor.
public final void wait(long timeout, int nanos) throws InterruptedException
This method is similar to the wait
method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up.
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify
method
or the notifyAll
method.
timeout
milliseconds plus nanos
nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution
This method should only be called by a thread that is the owner
of this object's monitor. See the notify
method for a
description of the ways in which a thread can become the owner of
a monitor.
public final void wait() throws InterruptedException
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify
method or the
notifyAll
method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify
method for a
description of the ways in which a thread can become the owner of
a monitor.
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