UUID

java.lang.Object
- org.jgroups.util.UUID

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Cloneable, java.lang.Comparable<Address>, Address, Streamable

Direct Known Subclasses:

AdditionalDataUUID, PayloadUUID, TopologyUUID
```
public class UUID
extends java.lang.Object
implements Address, Streamable, java.lang.Comparable<Address>
```
Logical address which is unique over space and time.
Copied from java.util.UUID, but unneeded fields from the latter have been removed. UUIDs needs to have a small memory footprint.

Author:

Bela Ban

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected byte[]`	`additional_data`
`protected static LazyRemovalCache<Address,java.lang.String>`	`cache` Keeps track of associations between logical addresses (UUIDs) and logical names
`protected long`	`leastSigBits`
`protected long`	`mostSigBits`
`protected static java.security.SecureRandom`	`numberGenerator` The random number generator used by this class to create random based UUIDs
`protected static LazyRemovalCache.Printable<Address,java.lang.String>`	`print_function`
`protected static boolean`	`print_uuids`
`protected static int`	`SIZE`

Fields inherited from interface org.jgroups.Address
IP_ADDR, NULL, UUID_ADDR

Constructor Summary

Constructors
Modifier	Constructor and Description
	`UUID()`
`protected`	`UUID(byte[] data)` Private constructor which uses a byte array to construct the new UUID
	`UUID(long mostSigBits, long leastSigBits)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static void`	`add(Address uuid, java.lang.String logical_name)`
`static void`	`add(java.util.Map<Address,java.lang.String> map)`
`java.lang.Object`	`clone()`
`int`	`compareTo(Address other)` Compares this UUID with the specified UUID.
`protected static java.lang.String`	`digits(long val, int digits)` Returns val represented by the specified number of hex digits.
`boolean`	`equals(java.lang.Object obj)` Compares this object to the specified object.
`static java.lang.String`	`get(Address logical_addr)`
`byte[]`	`getAdditionalData()` Deprecated. Will be removed in 3.0. This was only added to be backwards compatible with 2.7
`static java.util.Map<Address,java.lang.String>`	`getContents()` Returns a copy of the cache's contents
`long`	`getLeastSignificantBits()`
`long`	`getMostSignificantBits()` Returns the most significant 64 bits of this UUID's 128 bit value.
`int`	`hashCode()` Returns a hash code for this `UUID`.
`boolean`	`isMulticastAddress()` Checks whether this is an address that represents multiple destinations; e.g., a class D address in the Internet.
`static java.lang.String`	`printCache()`
`static UUID`	`randomUUID()` Static factory to retrieve a type 4 (pseudo randomly generated) UUID.
`void`	`readExternal(java.io.ObjectInput in)`
`void`	`readFrom(java.io.DataInputStream in)` Read the state of the current object (including superclasses) from instream Note that the input stream must not be closed
`static void`	`remove(Address addr)`
`static void`	`removeAll(java.util.Collection<Address> mbrs)`
`static void`	`retainAll(java.util.Collection<Address> logical_addrs)`
`void`	`setAdditionalData(byte[] additional_data)` Deprecated. Will be removed in 3.0. This was only added to be backwards compatible with 2.7
`int`	`size()` Returns serialized size of this address
`java.lang.String`	`toString()`
`java.lang.String`	`toStringLong()` Returns a `String` object representing this `UUID`.
`void`	`writeExternal(java.io.ObjectOutput out)`
`void`	`writeTo(java.io.DataOutputStream out)` Write the entire state of the current object (including superclasses) to outstream.

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

- Field Detail
  - mostSigBits
```
protected long mostSigBits
```
  - leastSigBits
```
protected long leastSigBits
```
  - additional_data
```
protected byte[] additional_data
```
  - numberGenerator
```
protected static volatile java.security.SecureRandom numberGenerator
```
    The random number generator used by this class to create random based UUIDs
  - cache
```
protected static LazyRemovalCache<Address,java.lang.String> cache
```
    Keeps track of associations between logical addresses (UUIDs) and logical names
  - print_uuids
```
protected static boolean print_uuids
```
  - SIZE
```
protected static final int SIZE
```
    See Also:
    
    Constant Field Values
  - print_function
```
protected static final LazyRemovalCache.Printable<Address,java.lang.String> print_function
```
- Constructor Detail
  - UUID
```
public UUID()
```
  - UUID
```
public UUID(long mostSigBits,
            long leastSigBits)
```
  - UUID
```
protected UUID(byte[] data)
```
    Private constructor which uses a byte array to construct the new UUID
- Method Detail
  - add
```
public static void add(Address uuid,
                       java.lang.String logical_name)
```
  - add
```
public static void add(java.util.Map<Address,java.lang.String> map)
```
  - get
```
public static java.lang.String get(Address logical_addr)
```
  - getContents
```
public static java.util.Map<Address,java.lang.String> getContents()
```
    Returns a copy of the cache's contents
  - remove
```
public static void remove(Address addr)
```
  - removeAll
```
public static void removeAll(java.util.Collection<Address> mbrs)
```
  - retainAll
```
public static void retainAll(java.util.Collection<Address> logical_addrs)
```
  - printCache
```
public static java.lang.String printCache()
```
  - getAdditionalData
```
public final byte[] getAdditionalData()
```
    Deprecated. Will be removed in 3.0. This was only added to be backwards compatible with 2.7
    
    Returns the additional_data.
    
    Returns:
    
    byte[]
    
    Since:
    
    2.8
  - setAdditionalData
```
public final void setAdditionalData(byte[] additional_data)
```
    Deprecated. Will be removed in 3.0. This was only added to be backwards compatible with 2.7
    
    Sets the additional_data.
    
    Parameters:
    
    additional_data - The additional_data to set
    
    Since:
    
    2.8
  - randomUUID
```
public static UUID randomUUID()
```
    Static factory to retrieve a type 4 (pseudo randomly generated) UUID. The UUID is generated using a cryptographically strong pseudo random number generator.
    
    Returns:
    
    A randomly generated UUID
  - getLeastSignificantBits
```
public long getLeastSignificantBits()
```
  - getMostSignificantBits
```
public long getMostSignificantBits()
```
    Returns the most significant 64 bits of this UUID's 128 bit value.
    
    Returns:
    
    The most significant 64 bits of this UUID's 128 bit value
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - toStringLong
```
public java.lang.String toStringLong()
```
    Returns a String object representing this UUID.
    The UUID string representation is as described by this BNF:
    UUID = <time_low> "-" <time_mid> "-" <time_high_and_version> "-" <variant_and_sequence> "-" <node> time_low = 4*<hexOctet> time_mid = 2*<hexOctet> time_high_and_version = 2*<hexOctet> variant_and_sequence = 2*<hexOctet> node = 6*<hexOctet> hexOctet = <hexDigit><hexDigit> hexDigit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" | "a" | "b" | "c" | "d" | "e" | "f" | "A" | "B" | "C" | "D" | "E" | "F"
    Returns:
    
    A string representation of this UUID
  - digits
```
protected static java.lang.String digits(long val,
                                         int digits)
```
    Returns val represented by the specified number of hex digits.
  - hashCode
```
public int hashCode()
```
    Returns a hash code for this UUID.
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    A hash code value for this UUID
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Compares this object to the specified object. The result is true if and only if the argument is not null, is a UUID object, has the same variant, and contains the same value, bit for bit, as this UUID.
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    obj - The object to be compared
    
    Returns:
    
    true if the objects are the same; false otherwise
  - compareTo
```
public int compareTo(Address other)
```
    Compares this UUID with the specified UUID.
    The first of two UUIDs is greater than the second if the most significant field in which the UUIDs differ is greater for the first UUID.
    
    Specified by:
    
    compareTo in interface java.lang.Comparable<Address>
    
    Parameters:
    
    other - UUID to which this UUID is to be compared
    
    Returns:
    
    -1, 0 or 1 as this UUID is less than, equal to, or greater than val
  - writeTo
```
public void writeTo(java.io.DataOutputStream out)
             throws java.io.IOException
```
    Description copied from interface: Streamable
    
    Write the entire state of the current object (including superclasses) to outstream. Note that the output stream must not be closed
    
    Specified by:
    
    writeTo in interface Streamable
    
    Throws:
    
    java.io.IOException
  - readFrom
```
public void readFrom(java.io.DataInputStream in)
              throws java.io.IOException,
                     java.lang.IllegalAccessException,
                     java.lang.InstantiationException
```
    Description copied from interface: Streamable
    
    Read the state of the current object (including superclasses) from instream Note that the input stream must not be closed
    
    Specified by:
    
    readFrom in interface Streamable
    
    Throws:
    
    java.io.IOException
    
    java.lang.IllegalAccessException
    
    java.lang.InstantiationException
  - isMulticastAddress
```
public boolean isMulticastAddress()
```
    Description copied from interface: Address
    
    Checks whether this is an address that represents multiple destinations; e.g., a class D address in the Internet.
    
    Specified by:
    
    isMulticastAddress in interface Address
    
    Returns:
    
    true if this is a multicast address, false if it is a unicast address
  - size
```
public int size()
```
    Description copied from interface: Address
    
    Returns serialized size of this address
    
    Specified by:
    
    size in interface Address
  - clone
```
public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException
```
    Overrides:
    
    clone in class java.lang.Object
    
    Throws:
    
    java.lang.CloneNotSupportedException
  - writeExternal
```
public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
```
    Specified by:
    
    writeExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException
  - readExternal
```
public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException
```
    Specified by:
    
    readExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException
    
    java.lang.ClassNotFoundException

Class UUID

Field Summary

Fields inherited from interface org.jgroups.Address

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

mostSigBits

leastSigBits

additional_data

numberGenerator

cache

print_uuids

SIZE

print_function

Constructor Detail

UUID

UUID

UUID

Method Detail

add

add

get

getContents

remove

removeAll

retainAll

printCache

getAdditionalData

setAdditionalData

randomUUID

getLeastSignificantBits

getMostSignificantBits

toString

toStringLong

digits

hashCode

equals

compareTo

writeTo

readFrom

isMulticastAddress

size

clone

writeExternal

readExternal