/*
 
* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code 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
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
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*/

package java.lang;

import java.io.Serializable;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectStreamException;

/**
 
* This is the common base class of all Java language enumeration types.
 
*
 
* More information about enums, including descriptions of the
 
* implicitly declared methods synthesized by the compiler, can be
 
* found in section 8.9 of
 
* <cite>The Java&trade; Language Specification</cite>.
 
*
 
* <p> Note that when using an enumeration type as the type of a set
 
* or as the type of the keys in a map, specialized and efficient
 
* {@linkplain java.util.EnumSet set} and {@linkplain
 
* java.util.EnumMap map} implementations are available.
 
*
 
* @param <E> The enum type subclass
 
* @author
  
Josh Bloch
 
* @author
  
Neal Gafter
 
* @see
     
Class#getEnumConstants()
 
* @see
     
java.util.EnumSet
 
* @see
     
java.util.EnumMap
 
* @since
   
1.5
 
*/

public abstract class Enum<E extends Enum<E>>
        
implements Comparable<E>, Serializable {
    
/**
     
* The name of this enum constant, as declared in the enum declaration.
     
* Most programmers should use the {@link #toString} method rather than
     
* accessing this field.
     
*/

    
private final String name;

    
/**
     
* Returns the name of this enum constant, exactly as declared in its
     
* enum declaration.
     
*
     
* <b>Most programmers should use the {@link #toString} method in
     
* preference to this one, as the toString method may return
     
* a more user-friendly name.</b>
  
This method is designed primarily for
     
* use in specialized situations where correctness depends on getting the
     
* exact name, which will not vary from release to release.
     
*
     
* @return the name of this enum constant
     
*/

    
public final String name() {
        
return name;
    
}

    
/**
     
* The ordinal of this enumeration constant (its position
     
* in the enum declaration, where the initial constant is assigned
     
* an ordinal of zero).
     
*
     
* Most programmers will have no use for this field.
  
It is designed
     
* for use by sophisticated enum-based data structures, such as
     
*
 
 
and {@link java.util.EnumMap}.
     
*/

    
private final int ordinal;

    
/**
     
* Returns the ordinal of this enumeration constant (its position
     
* in its enum declaration, where the initial constant is assigned
     
* an ordinal of zero).
     
*
     
* Most programmers will have no use for this method.
  
It is
     
* designed for use by sophisticated enum-based data structures, such
     
* as
 
 
and {@link java.util.EnumMap}.
     
*
     
* @return the ordinal of this enumeration constant
     
*/

    
public final int ordinal() {
        
return ordinal;
    
}

    
/**
     
* Sole constructor.
  
Programmers cannot invoke this constructor.
     
* It is for use by code emitted by the compiler in response to
     
* enum type declarations.
     
*
     
* @param name - The name of this enum constant, which is the identifier
     
*
               
used to declare it.
     
* @param ordinal - The ordinal of this enumeration constant (its position
     
*
         
in the enum declaration, where the initial constant is assigned
     
*
         
an ordinal of zero).
     
*/

    
protected Enum(String name, int ordinal) {
        
this.name = name;
        
this.ordinal = ordinal;
    
}

    
/**
     
* Returns the name of this enum constant, as contained in the
     
* declaration.
  
This method may be overridden, though it typically
     
* isn't necessary or desirable.
  
An enum type should override this
     
* method when a more "programmer-friendly" string form exists.
     
*
     
* @return the name of this enum constant
     
*/

    
public String toString() {
        
return name;
    
}

    
/**
     
* Returns true if the specified object is equal to this
     
* enum constant.
     
*
     
* @param other the object to be compared for equality with this object.
     
* @return
  
true if the specified object is equal to this
     
*
          
enum constant.
     
*/

    
public final boolean equals(Object other) {
        
return this==other;
    
}

    
/**
     
* Returns a hash code for this enum constant.
     
*
     
* @return a hash code for this enum constant.
     
*/
    
public final int hashCode() {
        
return super.hashCode();
    
}

    
/**
     
* Throws CloneNotSupportedException.
  
This guarantees that enums
     
* are never cloned, which is necessary to preserve their "singleton"
     
* status.
     
*
     
* @return (never returns)
     
*/

    
protected final Object clone() throws CloneNotSupportedException {
        
throw new CloneNotSupportedException();
    
}

    
/**
     
* Compares this enum with the specified object for order.
  
Returns a
     
* negative integer, zero, or a positive integer as this object is less
     
* than, equal to, or greater than the specified object.
     
*
     
* Enum constants are only comparable to other enum constants of the
     
* same enum type.
  
The natural order implemented by this
     
* method is the order in which the constants are declared.
     
*/

    
public final int compareTo(E o) {
        
Enum<?> other = (Enum<?>)o;
        
Enum<E> self = this;
        
if (self.getClass() != other.getClass() && // optimization
            
self.getDeclaringClass() != other.getDeclaringClass())
            
throw new ClassCastException();
        
return self.ordinal - other.ordinal;
    
}

    
/**
     
* Returns the Class object corresponding to this enum constant's
     
* enum type.
  
Two enum constants e1 ande2 are of the
     
* same enum type if and only if
     
*
   
e1.getDeclaringClass() == e2.getDeclaringClass().
     
* (The value returned by this method may differ from the one returned
     
* by the {@link Object#getClass} method for enum constants with
     
* constant-specific class bodies.)
     
*
     
* @return the Class object corresponding to this enum constant's
     
*enum type
     
*/

    
@SuppressWarnings("unchecked")
    
public final Class<E> getDeclaringClass() {
        
Class<?> clazz = getClass();
        
Class<?> zuper = clazz.getSuperclass();
        
return (zuper == Enum.class) ? (Class<E>)clazz : (Class<E>)zuper;
    
}

    
/**
     
* Returns the enum constant of the specified enum type with the
     
* specified name.
  
The name must match exactly an identifier used
     
* to declare an enum constant in this type.
  
(Extraneous whitespace
     
* characters are not permitted.)
     
*
     
* <p>Note that for a particular enum type {@code T}, the
     
* implicitly declared {@code public static T valueOf(String)}
     
* method on that enum may be used instead of this method to map
     
* from a name to the corresponding enum constant.
  
All the
     
* constants of an enum type can be obtained by calling the
     
* implicit {@code public static T[] values()} method of that
     
* type.
     
*
     
* @param <T> The enum type whose constant is to be returned
     
* @param enumType the {@code Class} object of the enum type from which
     
*
      
to return a constant
     
* @param name the name of the constant to return
     
* @return the enum constant of the specified enum type with the
     
*
      
specified name
     
* @throws IllegalArgumentException if the specified enum type has
     
*
         
no constant with the specified name, or the specified
     
*
         
class object does not represent an enum type
     
* @throws NullPointerException if {@code enumType} or {@code name}
     
*
         
is null
     
* @since 1.5
     
*/

    
public static <T extends Enum<T>> T valueOf(Class<T> enumType,
                                                
String name) {
        
T result = enumType.enumConstantDirectory().get(name);
        
if (result != null)
            
return result;
        
if (name == null)
            
throw new NullPointerException("Name is null");
        
throw new IllegalArgumentException(
            
"No enum constant " + enumType.getCanonicalName() + "." + name);
    
}

    
/**
     
* enum classes cannot have finalize methods.
     
*/
    
protected final void finalize() { }

    
/**
     
* prevent default deserialization
     
*/
    
private void readObject(ObjectInputStream in) throws IOException,
        
ClassNotFoundException {
        
throw new InvalidObjectException("can't deserialize enum");
    
}

    
private void readObjectNoData() throws ObjectStreamException {
        
throw new InvalidObjectException("can't deserialize enum");
    
}
}