com.plotnix.enum
Class Enum

java.lang.Object
  |
  +--com.plotnix.enum.Enum

All Implemented Interfaces:

java.io.Serializable

public class Enum

extends java.lang.Object

implements java.io.Serializable

Enum represents a value characterized by the following properties:

• It has an integer value that uniquely identifies it among other Enums belonging to the same class. By default, the integer value represents the order in which Enums are added to the class, starting with 0. Alternatively, an integer value can be assigned explicitly to the Enum in the constructor.
• It has a string value, which is also unique. By default, this string value is the name of a public static Enum field declared on this Enum's own class for this enum. If there is no such name and the string value was not explicitly specified in the constructor, then the string value is a string representation of the Enum's integer value.
• The toString() method of the Enum returns a human readable description of the Enum. The class attempts to locate a label for the constant in the resource bundle that has the same name as the class itself. If that fails and a default label was specified in the constructor, that label is returned. If no such label was specified, the string value of the constant is returned.

Static methods of the Enum class support:

• Loading an Enum from .property file
• Automatic generation of Enum objects from integer constants
• Retrieving an array of all constants of a given type
• Retrieving an individual constant of a given type by its string or integer value

Version:

$Revision$ $Date$

Author:

Dmitri Plotnikov

See Also:

Serialized Form

Constructor Summary

protected	Enum() Initialize the Enum, using default integer and string values.
protected	Enum(int integer) Initialize the Enum with an integer value.
protected	Enum(int integer, java.lang.String label) Initialize the Enum with an integer value and a default label.
protected	Enum(java.lang.String string) Initialize the Enum with a string value.
protected	Enum(java.lang.String string, java.lang.String label) Initialize the Enum with a string value and a default label.

Method Summary

static Enum[]	enum(java.lang.Class enumClass) Returns an array of all Enums of the specified class in the order they were created.
static Enum	enum(java.lang.Class enumClass, int integer) Returns the Enum of the specified class that has the specified integer value, or null if there is no such Enum.
static Enum	enum(java.lang.Class enumClass, java.lang.String string) Returns the Enum of the specified class that has the specified st, or null if there is no such Enum.
protected static void	initIntegerEnum(java.lang.Class enumClass)
int	intValue() Returns the Enum's integer value.
protected static void	loadEnum(java.lang.Class enumClass) Loads properties from an enumClass.properties resource file.
protected static void	loadIntegerEnum(java.lang.Class enumClass) Loads properties from an enumClass.properties resource file.
protected java.lang.Object	readResolve() Ensures uniqueness of Enums during deserialization.
java.lang.String	stringValue() Returns the string value of this Enum.
java.lang.String	toString() Returns this Enum's human readable description in the default locale.
java.lang.String	toString(java.util.Locale locale) Returns this Enum's human readable description in the specified locale.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Enum

protected Enum()

Initialize the Enum, using default integer and string values.

Enum

protected Enum(java.lang.String string)

Initialize the Enum with a string value. An integer value is assigned automatically.

Enum

protected Enum(java.lang.String string,
               java.lang.String label)

Initialize the Enum with a string value and a default label. An integer value is assigned automatically.

Enum

protected Enum(int integer)

Initialize the Enum with an integer value. A string value will be produced automatically.

Enum

protected Enum(int integer,
               java.lang.String label)

Initialize the Enum with an integer value and a default label. A string value will be produced automatically.

Method Detail

stringValue

public java.lang.String stringValue()

Returns the string value of this Enum. Depending on how the Enum was created, the method behaves differently:

If the constant was created as a public static Enum, the name of that field is returned.

If the constant was declared as a public static int, and registered with initIntegerEnum, the name of that integer field is returned.

If the constant was loaded from a .properties file, the corresponding property name is returned.

intValue

public int intValue()

Returns the Enum's integer value. An Enum can be allocated with an explicitly specified integer value. If the integer value is not specified, the Enum's constructor gives it a default one, which is computed by adding one to the integer value of the previous Enum of the same type.

toString

public java.lang.String toString()

Returns this Enum's human readable description in the default locale.

Overrides:

toString in class java.lang.Object

toString

public java.lang.String toString(java.util.Locale locale)

Returns this Enum's human readable description in the specified locale. If the resource bundle is not found or does not have a value for this Enum, the value of the default label specified during construction is returned. If that value was not unspecified, the Enum's string value is returned.

enum

public static Enum[] enum(java.lang.Class enumClass)

Returns an array of all Enums of the specified class in the order they were created.

enum

public static Enum enum(java.lang.Class enumClass,
                        java.lang.String string)

Returns the Enum of the specified class that has the specified st, or null if there is no such Enum.

enum

public static Enum enum(java.lang.Class enumClass,
                        int integer)

Returns the Enum of the specified class that has the specified integer value, or null if there is no such Enum.

initIntegerEnum

protected static void initIntegerEnum(java.lang.Class enumClass)

loadEnum

protected static void loadEnum(java.lang.Class enumClass)

Loads properties from an enumClass.properties resource file. Uses property names as string values of the Enums.

loadIntegerEnum

protected static void loadIntegerEnum(java.lang.Class enumClass)

Loads properties from an enumClass.properties resource file. Uses property names as integer values of the Enums.

readResolve

protected java.lang.Object readResolve()
                                throws java.io.ObjectStreamException

Ensures uniqueness of Enums during deserialization. Finds an Enum that is already declared with the same integer value and returns that Enum instead of the current instance.