org.apache.oozie.command.coord
Class CoordActionStartXCommand

java.lang.Object
  extended by org.apache.oozie.command.XCommand<T>
      extended by org.apache.oozie.command.coord.CoordinatorXCommand<Void>
          extended by 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, eventService, instrumentation, INSTRUMENTATION_GROUP, LOG, logInfo
 
Constructor Summary
CoordActionStartXCommand(String id, String user, String appName, 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.
 String getKey()
          Get command key
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.coord.CoordinatorXCommand
generateEvent, generateEvent
 
Methods inherited from class org.apache.oozie.command.XCommand
call, eagerVerifyPrecondition, executeInterrupts, getCreatedTime, getInstrumentation, 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 appName,
                                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

getKey

public String getKey()
Description copied from class: XCommand
Get command key

Specified by:
getKey in interface XCallable<Void>
Overrides:
getKey in class XCommand<Void>
Returns:
command key


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