org.cojen.dirmi.core

Class Identifier

java.lang.Object

org.cojen.dirmi.core.Identifier

All Implemented Interfaces:

Serializable, Comparable<org.cojen.dirmi.core.AbstractIdentifier>

public class Identifier
extends Object

Object which uniquely identifies another object. All Identifier instances themselves are identity comparable.

Author:

Brian S O'Neill

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
int	compareTo(org.cojen.dirmi.core.AbstractIdentifier id) Lexicographically compares two identifiers.
boolean	equals(Object obj)
int	hashCode()
static Identifier	identify(Object obj) Returns a new or existing unique identifier for the given object.
static Identifier	read(DataInput in) Returns a deserialized identifier, which may or may not have an object registered with it.
static Identifier	read(InputStream in) Returns a deserialized identifier, which may or may not have an object registered with it.
<T> void	register(T obj) Register the given object with this identifier.
String	toString()
Object	tryRetrieve() Returns the identified object, if it exists locally.
void	write(DataOutput out)
void	write(OutputStream out)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

identify

public static Identifier identify(Object obj)

Returns a new or existing unique identifier for the given object. If new, the given object is automatically registered with the identifier.

Throws:

IllegalArgumentException - if object is null

read

public static Identifier read(DataInput in)
                       throws IOException

Returns a deserialized identifier, which may or may not have an object registered with it.

Throws:

IOException

read

public static Identifier read(InputStream in)
                       throws IOException

Returns a deserialized identifier, which may or may not have an object registered with it.

Throws:

IOException

tryRetrieve

public Object tryRetrieve()

Returns the identified object, if it exists locally.

Returns:

identified object, or null if it doesn't exist locally.

register

public <T> void register(T obj)
                  throws IllegalArgumentException

Register the given object with this identifier. Registered objects are not strongly referenced, and so they may be garbage collected unless referenced elsewhere. Many objects can be registered with an identifier.

A registered object cannot be retrieved, but calling identify against a registered object returns the original identifier object.

Throws:

IllegalArgumentException - if given object is null

write

public void write(DataOutput out)
           throws IOException

Throws:

IOException

write

public void write(OutputStream out)
           throws IOException

Throws:

IOException

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(org.cojen.dirmi.core.AbstractIdentifier id)

Lexicographically compares two identifiers.

Specified by:

compareTo in interface Comparable<org.cojen.dirmi.core.AbstractIdentifier>