org.apache.oozie.service

Class UUIDService

java.lang.Object

org.apache.oozie.service.UUIDService

All Implemented Interfaces:

Service

Direct Known Subclasses:

ZKUUIDService

public class UUIDService
extends Object
implements Service

The UUID service generates unique IDs.

The configuration property CONF_GENERATOR specifies the ID generation type, 'random' or 'counter'.

For 'random' uses the JDK UUID.randomUUID() method.

For 'counter' uses a counter postfixed wit the system start up time.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	UUIDService.ApplicationType

Field Summary

Fields

Modifier and Type	Field and Description
static String	CONF_GENERATOR
static String	CONF_PREFIX
protected String	startTime

Fields inherited from interface org.apache.oozie.service.Service

DEFAULT_LOCK_TIMEOUT, lockTimeout

Constructor Summary

Constructors

Constructor and Description
UUIDService()

Method Summary

Methods

Modifier and Type	Method and Description
protected String	appendTimeToSequence(long id, String localStartTime)
protected String	createSequence()
void	destroy() Destroy the UUID service.
String	generateChildId(String id, String childName) Create a child ID.
String	generateId(UUIDService.ApplicationType type) Create a unique ID.
String	getChildName(String childId) Return the child name from a child ID.
protected long	getCounter()
String	getId(String childId) Return the ID from a child ID.
Class<? extends Service>	getInterface() Return the public interface for UUID service.
void	init(Services services) Initialize the UUID service.
protected String	longPadding(long number)
protected void	resetStartTime() reset start time

Methods inherited from class java.lang.Object

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

Field Detail

CONF_PREFIX

public static final String CONF_PREFIX

See Also:

Constant Field Values

CONF_GENERATOR

public static final String CONF_GENERATOR

See Also:

Constant Field Values

startTime

protected String startTime

Constructor Detail

UUIDService

public UUIDService()

Method Detail

init

public void init(Services services)
          throws ServiceException

Initialize the UUID service.

Specified by:

init in interface Service

Parameters:

services - services instance.

Throws:

ServiceException - thrown if the UUID service could not be initialized.

destroy

public void destroy()

Destroy the UUID service.

Specified by:

destroy in interface Service

resetStartTime

protected void resetStartTime()

reset start time

getInterface

public Class<? extends Service> getInterface()

Return the public interface for UUID service.

Specified by:

getInterface in interface Service

Returns:

UUIDService.

longPadding

protected String longPadding(long number)

generateId

public String generateId(UUIDService.ApplicationType type)

Create a unique ID.

Parameters:

type: - Type of Id. Generally 'C' for Coordinator and 'W' for Workflow.

Returns:

unique ID.

createSequence

protected String createSequence()

getCounter

protected long getCounter()

appendTimeToSequence

protected String appendTimeToSequence(long id,
                          String localStartTime)

generateChildId

public String generateChildId(String id,
                     String childName)

Create a child ID.

If the same child name is given the returned child ID is the same.

Parameters:

id - unique ID.

childName - child name.

Returns:

a child ID.

getId

public String getId(String childId)

Return the ID from a child ID.

Parameters:

childId - child ID.

Returns:

ID of the child ID.

getChildName

public String getChildName(String childId)

Return the child name from a child ID.

Parameters:

childId - child ID.

Returns:

child name.