java.lang

Class Enum<T,extends,Enum,T>

Implemented Interfaces:
Comparable<T>, Serializable

public abstract class Enum<T,extends,Enum,T>
extends Object
implements Comparable<T>, Serializable

This class represents a Java enumeration. All enumerations are subclasses of this class.
Since:
1.5
See Also:
Serialized Form

Constructor Summary

Enum(String name, int ordinal)
This constructor is used by the compiler to create enumeration constants.

Method Summary

protected Object
clone()
Cloning of enumeration constants is prevented, to maintain their singleton status.
int
compareTo(T e)
Returns an integer which represents the relative ordering of this enumeration constant.
boolean
equals(Object o)
Returns true if this enumeration is equivalent to the supplied object, o.
static
extends Enum> S valueOf(Class etype, String s)
Returns an Enum for a enum class given a description string of the enum constant.
protected void
finalize()
Enumerations can not have finalization methods.
Class
getDeclaringClass()
Returns the type of this enumeration constant.
int
hashCode()
Returns the hash code of this constant.
String
name()
Returns the name of this enumeration constant.
int
ordinal()
Returns the number of this enumeration constant, which represents the order in which it was originally declared, starting from zero.
String
toString()
Returns a textual representation of this enumeration constant.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Enum

protected Enum(String name,
               int ordinal)
This constructor is used by the compiler to create enumeration constants.
Parameters:
name - the name of the enumeration constant.
ordinal - the number of the enumeration constant, based on the declaration order of the constants and starting from zero.

Method Details

clone

protected final Object clone()
            throws CloneNotSupportedException
Cloning of enumeration constants is prevented, to maintain their singleton status.
Overrides:
clone in interface Object
Returns:
the cloned object.
Throws:
CloneNotSupportedException - as enumeration constants can't be cloned.

compareTo

public final int compareTo(T e)
Returns an integer which represents the relative ordering of this enumeration constant. Enumeration constants are ordered by their ordinals, which represents their declaration order. So, comparing two identical constants yields zero, while one declared prior to this returns a positive integer and one declared after yields a negative integer.
Specified by:
compareTo in interface Comparable<T>
Parameters:
e - the enumeration constant to compare.
Returns:
a negative integer if e.ordinal <32this.ordinal, zero if e.ordinal == this.ordinal and a positive integer if e.ordinal > this.ordinal.
Throws:
ClassCastException - if e is not an enumeration constant of the same class.

equals

public final boolean equals(Object o)
Returns true if this enumeration is equivalent to the supplied object, o. Only one instance of an enumeration constant exists, so the comparison is simply done using ==.
Overrides:
equals in interface Object
Parameters:
o - the object to compare to this.
Returns:
true if this == o.

extends Enum> S valueOf

public static extends Enum> S valueOf(Class etype,
                                            String s)
Returns an Enum for a enum class given a description string of the enum constant.
Throws:
NullPointerException - when etype or s are null.
IllegalArgumentException - when there is no value s in the enum etype.

finalize

protected final void finalize()
Enumerations can not have finalization methods.
Overrides:
finalize in interface Object
Since:
1.6

getDeclaringClass

public final Class getDeclaringClass()
Returns the type of this enumeration constant. This is the class corresponding to the declaration of the enumeration.
Returns:
the type of this enumeration constant.

hashCode

public final int hashCode()
Returns the hash code of this constant. This is simply the ordinal.
Overrides:
hashCode in interface Object
Returns:
the hash code of this enumeration constant.

name

public final String name()
Returns the name of this enumeration constant.
Returns:
the name of the constant.

ordinal

public final int ordinal()
Returns the number of this enumeration constant, which represents the order in which it was originally declared, starting from zero.
Returns:
the number of this constant.

toString

public String toString()
Returns a textual representation of this enumeration constant. By default, this is simply the declared name of the constant, but specific enumeration types may provide an implementation more suited to the data being stored.
Overrides:
toString in interface Object
Returns:
a textual representation of this constant.

Enum.java - Base class for all enums Copyright (C) 2004, 2005 Free Software Foundation This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.