org.apache.oozie.command.coord
Class CoordActionStartXCommand

java.lang.Object
  org.apache.oozie.command.XCommand<T>
      org.apache.oozie.command.coord.CoordinatorXCommand<Void>
          org.apache.oozie.command.coord.CoordActionStartXCommand

All Implemented Interfaces:

Callable<Void>, XCallable<Void>

public class CoordActionStartXCommand
extends CoordinatorXCommand<Void>

Field Summary

static String	COULD_NOT_START
static String	EL_ERROR
static String	EL_EVAL_ERROR
static String	EXEC_DATA_MISSING
static String	START_DATA_MISSING

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

DEFAULT_LOCK_TIMEOUT, DEFAULT_REQUEUE_DELAY, dryrun, instrumentation, INSTRUMENTATION_GROUP, LOG, logInfo

Constructor Summary

CoordActionStartXCommand(String id, String user, String token, String jobId)

Method Summary

protected void	eagerLoadState() Load the necessary state to perform an eager precondition check.
protected Void	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, 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

Field Detail

EL_ERROR

public static final String EL_ERROR

See Also:

Constant Field Values

EL_EVAL_ERROR

public static final String EL_EVAL_ERROR

See Also:

Constant Field Values

COULD_NOT_START

public static final String COULD_NOT_START

See Also:

Constant Field Values

START_DATA_MISSING

public static final String START_DATA_MISSING

See Also:

Constant Field Values

EXEC_DATA_MISSING

public static final String EXEC_DATA_MISSING

See Also:

Constant Field Values

Constructor Detail

CoordActionStartXCommand

public CoordActionStartXCommand(String id,
                                String user,
                                String token,
                                String jobId)

Method Detail

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.

getEntityKey

public String getEntityKey()

Description copied from class: XCommand

Return the entity key for the command.

Specified by:

getEntityKey in interface XCallable<Void>

Specified by:

getEntityKey in class XCommand<Void>

Returns:

the entity key for the command.

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

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

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

verifyPrecondition

protected void verifyPrecondition()
                           throws 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:

PreconditionException