org.apache.oozie.command.wf
Class ExternalIdXCommand

java.lang.Object
  extended by org.apache.oozie.command.XCommand<T>
      extended by org.apache.oozie.command.wf.WorkflowXCommand<String>
          extended by org.apache.oozie.command.wf.ExternalIdXCommand
All Implemented Interfaces:
Callable<String>, XCallable<String>

public class ExternalIdXCommand
extends WorkflowXCommand<String>


Field Summary
 
Fields inherited from class org.apache.oozie.command.XCommand
DEFAULT_LOCK_TIMEOUT, DEFAULT_REQUEUE_DELAY, dryrun, instrumentation, INSTRUMENTATION_GROUP, LOG, logInfo
 
Constructor Summary
ExternalIdXCommand(String externalId)
           
 
Method Summary
protected  String execute()
          Command execution body.
 String getEntityKey()
          Return the entity key for the command.
protected  boolean isLockRequired()
          Indicate if the the command requires locking.
protected  void loadState()
          Load the necessary state to perform the precondition check and to execute the command.
protected  void verifyPrecondition()
          Verify the precondition for the command after a lock has been obtain, just before executing the command.
 
Methods inherited from class org.apache.oozie.command.XCommand
call, eagerLoadState, eagerVerifyPrecondition, executeInterrupts, getCreatedTime, getInstrumentation, getKey, getLockTimeOut, getLog, getName, getPriority, getRequeueDelay, getType, inInterruptMode, isReQueueRequired, queue, queue, resetUsed, setInterruptMode
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ExternalIdXCommand

public ExternalIdXCommand(String externalId)
Method Detail

isLockRequired

protected boolean isLockRequired()
Description copied from class: XCommand
Indicate if the the command requires locking.

Subclasses should override this method if they require locking.

Specified by:
isLockRequired in class XCommand<String>
Returns:
true/false

getEntityKey

public String getEntityKey()
Description copied from class: XCommand
Return the entity key for the command.

Specified by:
getEntityKey in interface XCallable<String>
Specified by:
getEntityKey in class XCommand<String>
Returns:
the entity key for the command.

loadState

protected void loadState()
                  throws CommandException
Description copied from class: XCommand
Load the necessary state to perform the precondition check and to execute the command.

Subclasses must implement this method and load the state needed to do the precondition check and execute the command.

Specified by:
loadState in class XCommand<String>
Throws:
CommandException

verifyPrecondition

protected void verifyPrecondition()
                           throws CommandException,
                                  PreconditionException
Description copied from class: XCommand
Verify the precondition for the command after a lock has been obtain, just before executing the command.

Specified by:
verifyPrecondition in class XCommand<String>
Throws:
CommandException - thrown if the precondition is not met.
PreconditionException

execute

protected String execute()
                  throws CommandException
Description copied from class: XCommand
Command execution body.

This method will be invoked after the {link #loadState} and {link #verifyPrecondition} methods.

If the command requires locking, this method will be invoked ONLY if the lock has been acquired.

Specified by:
execute in class XCommand<String>
Returns:
a return value from the execution of the command, only meaningful if the command is executed synchronously.
Throws:
CommandException - thrown if the command execution failed.


Copyright © 2013 Apache Software Foundation. All Rights Reserved.