ObjID JDK 1.6)

Description

publicfinal class ObjID

An ObjID is used to identify a remote object exported to an RMI runtime.

An ObjID is used to identify a remote object exported to an RMI runtime. When a remote object is exported, it is assigned an object identifier either implicitly or explicitly, depending on the API used to export.

The ObjID.ObjID() constructor can be used to generate a unique object identifier. Such an ObjID is unique over time with respect to the host it is generated on. The ObjID.ObjID(int) constructor can be used to create a "well-known" object identifier. The scope of a well-known ObjID depends on the RMI runtime it is exported to.

An ObjID instance contains an object number (of type long) and an address space identifier (of type UID). In a unique ObjID, the address space identifier is unique with respect to a given host over time. In a well-known ObjID, the address space identifier is equivalent to one returned by invoking the UID.UID(short) constructor with the value zero.

If the system property java.rmi.server.randomIDs is defined to equal the string "true" (case insensitive), then the ObjID.ObjID() constructor will use a cryptographically strong random number generator to choose the object number of the returned ObjID.

See also:

Constructors

public ObjID ()

Generates a unique object identifier.

public ObjID (int objNum)

Creates a "well-known" object identifier.

private ObjID (long objNum, UID space)

Constructs an object identifier given data read from a stream.

Methods

Hide/Show inherited methods

public boolean equals (Object obj)

Compares the specified object with this ObjID for equality.

Compares the specified object with this ObjID for
equality.

This method returns true if and only if the
specified object is an ObjID instance with the same
object number and address space identifier as this one.
Returns: true if the given object is equivalent to this one, and false otherwise
Parameters:
- obj - the object to compare this ObjID to

public int hashCode ()

Returns the hash code value for this object identifier, the object number.

publicstatic ObjID read (ObjectInput in) throws IOException

Constructs and returns a new ObjID instance by unmarshalling a binary representation from an ObjectInput instance.

Specifically, this method first invokes the given stream's DataInput.readLong() method to read an object number, then it invokes UID.read(DataInput) with the stream to read an address space identifier, and then it creates and returns a new ObjID instance that contains the object number and address space identifier that were read from the stream.
Returns: unmarshalled ObjID instance
Parameters:
- in - the ObjectInput instance to read ObjID from
Throws:
- IOException - if an I/O error occurs while performing this operation

public String toString ()

Returns a string representation of this object identifier.

public void write (ObjectOutput out) throws IOException

Marshals a binary representation of this ObjID to an ObjectOutput instance.

Specifically, this method first invokes the given stream's DataOutput.writeLong(long) method with this object identifier's object number, and then it writes its address space identifier by invoking its UID.write(DataOutput) method with the stream.
Parameters:
- out - the ObjectOutput instance to write this ObjID to
Throws:
- IOException - if an I/O error occurs while performing this operation