ObjID (Java Platform SE 7 b138)

java.lang.Object
- java.rmi.server.ObjID

All Implemented Interfaces:

Serializable
```
public final class ObjID
extends Object
implements Serializable
```
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() 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(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() constructor will use a cryptographically strong random number generator to choose the object number of the returned ObjID.

Since:

JDK1.1

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`ACTIVATOR_ID` Object number for well-known `ObjID` of the activator.
`static int`	`DGC_ID` Object number for well-known `ObjID` of the distributed garbage collector.
`static int`	`REGISTRY_ID` Object number for well-known `ObjID` of the registry.

Constructor Summary

Constructors
Constructor and Description

ObjID()
Generates a unique object identifier.

ObjID(int objNum)
Creates a "well-known" object identifier.

Constructors
Constructor and Description
`ObjID()` Generates a unique object identifier.
`ObjID(int objNum)` Creates a "well-known" object identifier.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`equals(Object obj)` Compares the specified object with this `ObjID` for equality.
`int`	`hashCode()` Returns the hash code value for this object identifier, the object number.
`static ObjID`	`read(ObjectInput in)` Constructs and returns a new `ObjID` instance by unmarshalling a binary representation from an `ObjectInput` instance.
`String`	`toString()` Returns a string representation of this object identifier.
`void`	`write(ObjectOutput out)` Marshals a binary representation of this `ObjID` to an `ObjectOutput` instance.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - REGISTRY_ID
```
public static final int REGISTRY_ID
```
    Object number for well-known ObjID of the registry.
    
    See Also:
    Constant Field Values
  - ACTIVATOR_ID
```
public static final int ACTIVATOR_ID
```
    Object number for well-known ObjID of the activator.
    
    See Also:
    Constant Field Values
  - DGC_ID
```
public static final int DGC_ID
```
    Object number for well-known ObjID of the distributed garbage collector.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - ObjID
```
public ObjID()
```
    Generates a unique object identifier.
    If the system property java.rmi.server.randomIDs is defined to equal the string "true" (case insensitive), then this constructor will use a cryptographically strong random number generator to choose the object number of the returned ObjID.
  - ObjID
```
public ObjID(int objNum)
```
    Creates a "well-known" object identifier.
    An ObjID created via this constructor will not clash with any ObjIDs generated via the no-arg constructor.
    
    Parameters:
    objNum - object number for well-known object identifier
- Method Detail
  - write
```
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
  - read
```
public static 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.
    
    Parameters:
    in - the ObjectInput instance to read ObjID from
    
    Returns:
    unmarshalled ObjID instance
    
    Throws:
    
    IOException - if an I/O error occurs while performing this operation
  - hashCode
```
public int hashCode()
```
    Returns the hash code value for this object identifier, the object number.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    the hash code value for this object identifier
    See Also:
    Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)
  - equals
```
public boolean equals(Object obj)
```
    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.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    obj - the object to compare this ObjID to
    
    Returns:
    true if the given object is equivalent to this one, and false otherwise
    See Also:
    Object.hashCode(), HashMap
  - toString
```
public String toString()
```
    Returns a string representation of this object identifier.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    a string representation of this object identifier

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.
DRAFT ea-b138

Class ObjID

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

REGISTRY_ID

ACTIVATOR_ID

DGC_ID

Constructor Detail

ObjID

ObjID

Method Detail

write

read

hashCode

equals

toString