org.apache.commons.id
Class ConstantIdentifierGenerator

java.lang.Object
  org.apache.commons.id.AbstractStringIdentifierGenerator
      org.apache.commons.id.ConstantIdentifierGenerator

All Implemented Interfaces:

IdentifierGenerator, StringIdentifierGenerator

public class ConstantIdentifierGenerator
extends AbstractStringIdentifierGenerator

StringIdentifierGenerator that always returns the same string. Use with CompositeIdentifierGenerator to embed constant string identifiers, or to add prefixes or suffixes.

Null constant values are not allowed. The default (assumed by the argumentless constructor) is an empty string.

Version:

$Id$

Author:

Commons-Id team

Field Summary

Fields inherited from class org.apache.commons.id.AbstractStringIdentifierGenerator

ALPHA_NUMERIC_CHARSET_SIZE, DEFAULT_ALPHANUMERIC_IDENTIFIER_SIZE, MAX_INT_ALPHANUMERIC_VALUE_LENGTH, MAX_INT_NUMERIC_VALUE_LENGTH, MAX_LONG_ALPHANUMERIC_VALUE_LENGTH, MAX_LONG_NUMERIC_VALUE_LENGTH

Fields inherited from interface org.apache.commons.id.StringIdentifierGenerator

INFINITE_MAX_LENGTH

Constructor Summary

ConstantIdentifierGenerator()
Creates a new ConstantIdentifierGenerator using the default (empty string) constant value.

ConstantIdentifierGenerator(java.lang.String identifier)
Creates a new ConstantIdentifierGenerator using the given constant value.

Method Summary

static StringIdentifierGenerator	getInstance(java.lang.String identifier) Factory method to create a new ConstantIdentifierGenerator with the given constant value.
long	maxLength() Returns the length of the constant string returned by this generator.
long	minLength() Returns the length of the constant string returned by this generator.
java.lang.String	nextStringIdentifier() Gets the next identifier in the sequence.

Methods inherited from class org.apache.commons.id.AbstractStringIdentifierGenerator

nextIdentifier

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstantIdentifierGenerator

public ConstantIdentifierGenerator()

Creates a new ConstantIdentifierGenerator using the default (empty string) constant value.

ConstantIdentifierGenerator

public ConstantIdentifierGenerator(java.lang.String identifier)

Creates a new ConstantIdentifierGenerator using the given constant value.

Null constant values are not allowed.

Parameters:

identifier - constant value returned by the generator. Must not be null.

Throws:

IllegalArgumentExeption - if identifier is null

Method Detail

getInstance

public static StringIdentifierGenerator getInstance(java.lang.String identifier)

Factory method to create a new ConstantIdentifierGenerator with the given constant value. Does not allow null values.

Parameters:

identifier - constant value returned by the newly created generator. Must not be null.

Returns:

a new ConstantIdentifierGenerator

Throws:

java.lang.IllegalArgumentException - if identifier is null

nextStringIdentifier

public java.lang.String nextStringIdentifier()

Description copied from interface: StringIdentifierGenerator

Gets the next identifier in the sequence.

Specified by:

nextStringIdentifier in interface StringIdentifierGenerator

Specified by:

nextStringIdentifier in class AbstractStringIdentifierGenerator

Returns:

the next String identifier in sequence

maxLength

public long maxLength()

Returns the length of the constant string returned by this generator. If the constant is null or an empty string, 0 is returned.

Specified by:

maxLength in interface StringIdentifierGenerator

Overrides:

maxLength in class AbstractStringIdentifierGenerator

Returns:

the length of the constant string returned by this generator

minLength

public long minLength()

Returns the length of the constant string returned by this generator. If the constant is null or an empty string, 0 is returned.

Specified by:

minLength in interface StringIdentifierGenerator

Overrides:

minLength in class AbstractStringIdentifierGenerator

Returns:

the length of the constant string returned by this generator