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org.apache.oozie.command.wf
Class ActionCheckXCommand

java.lang.Object
  org.apache.oozie.command.XCommand<T>
      org.apache.oozie.command.wf.WorkflowXCommand<Void>
          org.apache.oozie.command.wf.ActionXCommand<Void>
              org.apache.oozie.command.wf.ActionCheckXCommand

All Implemented Interfaces:

Callable<Void>, XCallable<Void>

public class ActionCheckXCommand
extends ActionXCommand<Void>

Executes the check command for ActionHandlers.

Ensures the action is in RUNNING state before executing ActionExecutor.check(org.apache.oozie.action.ActionExecutor.Context, org.apache.oozie.client.WorkflowAction)

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.oozie.command.wf.ActionXCommand

ActionXCommand.ActionExecutorContext

Field Summary

static String

EXEC_DATA_MISSING

Fields inherited from class org.apache.oozie.command.wf.ActionXCommand

INSTR_FAILED_JOBS_COUNTER, RECOVERY_ID_SEPARATOR

Fields inherited from class org.apache.oozie.command.XCommand

DEFAULT_LOCK_TIMEOUT, DEFAULT_REQUEUE_DELAY, dryrun, instrumentation, LOG, logInfo

Constructor Summary

ActionCheckXCommand(String actionId)

ActionCheckXCommand(String actionId, int checkDelay)

ActionCheckXCommand(String actionId, int priority, int checkDelay)

Method Summary

protected void	eagerLoadState() Load the necessary state to perform an eager precondition check.
protected void	eagerVerifyPrecondition() Verify the precondition for the command before obtaining a lock.
protected Void	execute() Command execution body.
protected 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.wf.ActionXCommand

addActionCron, failJob, handleError, handleNonTransient, handleTransient, handleUserRetry, incrActionCounter

Methods inherited from class org.apache.oozie.command.XCommand

call, getCreatedTime, getInstrumentation, getKey, getLockTimeOut, getLog, getName, getPriority, getRequeueDelay, getType, isReQueueRequired, queue, queue, resetUsed

Methods inherited from class java.lang.Object

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

Field Detail

EXEC_DATA_MISSING

public static final String EXEC_DATA_MISSING

See Also:

Constant Field Values

Constructor Detail

ActionCheckXCommand

public ActionCheckXCommand(String actionId)

ActionCheckXCommand

public ActionCheckXCommand(String actionId,
                           int priority,
                           int checkDelay)

ActionCheckXCommand

public ActionCheckXCommand(String actionId,
                           int checkDelay)

Method Detail

eagerLoadState

protected void eagerLoadState()
                       throws CommandException

Description copied from class: XCommand

Load the necessary state to perform an eager precondition check.

This implementation does a NOP.

Subclasses should override this method and load the state needed to do an eager precondition check.

A trivial implementation is calling {link #loadState}.

Overrides:

eagerLoadState in class XCommand<Void>

Throws:

CommandException

eagerVerifyPrecondition

protected void eagerVerifyPrecondition()
                                throws CommandException,
                                       PreconditionException

Description copied from class: XCommand

Verify the precondition for the command before obtaining a lock.

This implementation does a NOP.

A trivial implementation is calling {link #verifyPrecondition}.

Overrides:

eagerVerifyPrecondition in class XCommand<Void>

Throws:

CommandException - thrown if the precondition is not met.

PreconditionException

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<Void>

Returns:

true/false

getEntityKey

protected String getEntityKey()

Description copied from class: XCommand

Return the entity key for the command.

Specified by:

getEntityKey in class XCommand<Void>

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<Void>

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<Void>

Throws:

CommandException - thrown if the precondition is not met.

PreconditionException

execute

protected Void 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<Void>

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.