Module java.desktop

Package javax.print.attribute

Class EnumSyntax

java.lang.Object

javax.print.attribute.EnumSyntax

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

Chromaticity, ColorSupported, Compression, DialogTypeSelection, Fidelity, Finishings, JobSheets, JobState, JobStateReason, Media, MultipleDocumentHandling, OrientationRequested, PDLOverrideSupported, PresentationDirection, PrinterIsAcceptingJobs, PrinterState, PrinterStateReason, PrintQuality, ReferenceUriSchemesSupported, Severity, SheetCollate, Sides

public abstract class EnumSyntax
extends Object
implements Serializable, Cloneable

Class EnumSyntax is an abstract base class providing the common implementation of all "type safe enumeration" objects. An enumeration class (which extends class EnumSyntax) provides a group of enumeration values (objects) that are singleton instances of the enumeration class; for example:

     public class Bach extends EnumSyntax {
         public static final Bach JOHANN_SEBASTIAN     = new Bach(0);
         public static final Bach WILHELM_FRIEDEMANN   = new Bach(1);
         public static final Bach CARL_PHILIP_EMMANUEL = new Bach(2);
         public static final Bach JOHANN_CHRISTIAN     = new Bach(3);
         public static final Bach P_D_Q                = new Bach(4);

         private static final String[] stringTable = {
             "Johann Sebastian Bach",
              "Wilhelm Friedemann Bach",
              "Carl Philip Emmanuel Bach",
              "Johann Christian Bach",
              "P.D.Q. Bach"
         };

         protected String[] getStringTable() {
             return stringTable;
         }

         private static final Bach[] enumValueTable = {
             JOHANN_SEBASTIAN,
              WILHELM_FRIEDEMANN,
              CARL_PHILIP_EMMANUEL,
              JOHANN_CHRISTIAN,
              P_D_Q
         };

         protected EnumSyntax[] getEnumValueTable() {
             return enumValueTable;
         }
     }
 

You can then write code that uses the == and != operators to test enumeration values; for example:

     Bach theComposer;
     . . .
     if (theComposer == Bach.JOHANN_SEBASTIAN) {
         System.out.println ("The greatest composer of all time!");
     }
 

The equals() method for an enumeration class just does a test for identical objects (==).

You can convert an enumeration value to a string by calling toString(). The string is obtained from a table supplied by the enumeration class.

Under the hood, an enumeration value is just an integer, a different integer for each enumeration value within an enumeration class. You can get an enumeration value's integer value by calling getValue(). An enumeration value's integer value is established when it is constructed (see EnumSyntax(int)). Since the constructor is protected, the only possible enumeration values are the singleton objects declared in the enumeration class; additional enumeration values cannot be created at run time.

You can define a subclass of an enumeration class that extends it with additional enumeration values. The subclass's enumeration values' integer values need not be distinct from the superclass's enumeration values' integer values; the ==, !=, equals(), and toString() methods will still work properly even if the subclass uses some of the same integer values as the superclass. However, the application in which the enumeration class and subclass are used may need to have distinct integer values in the superclass and subclass.

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	EnumSyntax(int value)	Construct a new enumeration value with the given integer value.

Method Summary

Modifier and Type	Method	Description
Object	clone()	Returns a clone of this enumeration value, which to preserve the semantics of enumeration values is the same object as this enumeration value.
protected EnumSyntax[]	getEnumValueTable()	Returns the enumeration value table for this enumeration value's enumeration class.
protected int	getOffset()	Returns the lowest integer value used by this enumeration value's enumeration class.
protected String[]	getStringTable()	Returns the string table for this enumeration value's enumeration class.
int	getValue()	Returns this enumeration value's integer value.
int	hashCode()	Returns a hash code value for this enumeration value.
protected Object	readResolve()	During object input, convert this deserialized enumeration instance to the proper enumeration value defined in the enumeration attribute class.
String