EnumSyntax (Java SE 17 & JDK 17)
Description: declaration: module: java.desktop, package: javax.print.attribute, class: EnumSyntax
Keywords: javax.print.attribute.EnumSyntax class

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`
  `toString()`
  Returns a string value corresponding to this enumeration value.

  ### Methods declared in class java.lang.Object

  `equals, finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### EnumSyntax

    protected EnumSyntax(int value)
    Construct a new enumeration value with the given integer value.
    Parameters:
      `value` - Integer value

- ## Method Details

  - ### getValue

    public int getValue()
    Returns this enumeration value's integer value.
    Returns:
      the value

  - ### clone

    public 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.
    Overrides:
      `clone` in class `Object`
    Returns:
      a clone of this instance.
    See Also:
      - `Cloneable`

  - ### hashCode

    public int hashCode()
    Returns a hash code value for this enumeration value. The hash code is just this enumeration value's integer value.
    Overrides:
      `hashCode` in class `Object`
    Returns:
      a hash code value for this object.
    See Also:
      - `Object.equals(java.lang.Object)`
      - `System.identityHashCode(java.lang.Object)`

  - ### toString

    public String toString()
    Returns a string value corresponding to this enumeration value.
    Overrides:
      `toString` in class `Object`
    Returns:
      a string representation of the object.

  - ### readResolve

    protected Object readResolve() throws ObjectStreamException
    During object input, convert this deserialized enumeration instance to the proper enumeration value defined in the enumeration attribute class.
    Returns:
      The enumeration singleton value stored at index i-L in the enumeration value table returned by `getEnumValueTable()`, where i is this enumeration value's integer value and L is the value returned by `getOffset()`
    Throws:
      `ObjectStreamException` - if the stream can't be deserialised
      `InvalidObjectException` - if the enumeration value table is `null`, this enumeration value's integer value does not correspond to an element in the enumeration value table, or the corresponding element in the enumeration value table is `null`. (Note: `InvalidObjectException` is a subclass of `ObjectStreamException`, which `readResolve()` is declared to throw.)

  - ### getStringTable

    protected String[] getStringTable()
    Returns the string table for this enumeration value's enumeration class. The enumeration class's integer values are assumed to lie in the range L..L+N-1, where L is the value returned by `getOffset()` and N is the length of the string table. The element in the string table at index i-L is the value returned by `toString()` for the enumeration value whose integer value is i. If an integer within the above range is not used by any enumeration value, leave the corresponding table element `null`.

    The default implementation returns `null`. If the enumeration class (a subclass of class `EnumSyntax`) does not override this method to return a `non-null` string table, and the subclass does not override the `toString()` method, the base class `toString()` method will return just a string representation of this enumeration value's integer value.

    Returns:
      the string table

  - ### getEnumValueTable

    protected EnumSyntax[] getEnumValueTable()
    Returns the enumeration value table for this enumeration value's enumeration class. The enumeration class's integer values are assumed to lie in the range L..L+N-1, where L is the value returned by `getOffset()` and N is the length of the enumeration value table. The element in the enumeration value table at index i-L is the enumeration value object whose integer value is i; the `readResolve()` method needs this to preserve singleton semantics during deserialization of an enumeration instance. If an integer within the above range is not used by any enumeration value, leave the corresponding table element `null`.

    The default implementation returns `null`. If the enumeration class (a subclass of class EnumSyntax) does not override this method to return a `non-null` enumeration value table, and the subclass does not override the `readResolve()` method, the base class `readResolve()` method will throw an exception whenever an enumeration instance is deserialized from an object input stream.

    Returns:
      the value table

  - ### getOffset

    protected int getOffset()
    Returns the lowest integer value used by this enumeration value's enumeration class.

    The default implementation returns 0. If the enumeration class (a subclass of class `EnumSyntax`) uses integer values starting at other than 0, override this method in the subclass.

    Returns:
      the offset of the lowest enumeration value