|Modifier and Type||Method and Description|
Indicates whether some other object is "equal to" this one.
Returns a hash code value for the object.
Returns the JNI-style signature for this type.
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
For primitive classes
the returned signature is the signature of the corresponding primitive
type; for example, "I" is returned as the signature of the class
equals method implements an equivalence relation
on non-null object references:
trueif and only if
y, multiple invocations of x.equals(y) consistently return
trueor consistently return
false, provided no information used in
equalscomparisons on the objects is modified.
The equals method for class
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values
y, this method returns
true if and only
y refer to the same object
x == y has the value
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
public int hashCode()
The general contract of
hashCodemethod on each of the two objects must produce the same integer result.
Object.equals(java.lang.Object)method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)