Package com.onenetwork.platform.grid

Interface TaskPerformer

All Known Implementing Classes:
AbstractTaskPerformer
public interface TaskPerformer
Classes implementing the TaskPerformer interface are created and called by the Grid Dispatcher to perform a task of the type returned by getTaskType().

A single TaskPerformer object is associated with a single thread. TaskPerformer implementations do not have to worry about more than one thread accessing a single TaskPerformer object at a time. A single TaskPerformer object will be used over and over again to process tasks of the specified task type. If the TaskPerformer keeps any state, it should make sure that the state is cleared each time performTask is called.

Clients are encouraged to use AbstractTaskPerformer as the base class for their TaskPerformer implementations.

  • Method Summary

    Modifier and Type Method Description
    void addToFailTransaction​(java.lang.String taskParams, java.lang.String taskInput, java.lang.String reason)
    After a result of FAIL, this gives the TaskPerformer the opportunity to perform an action which may update the database.
    void addToRetryTransaction​(java.lang.String taskParams, java.lang.String taskInput, java.lang.String reason)
    After a result of RETRY, this gives the TaskPerformer the opportunity to perform an action which may update the database.
    TaskPerformerConfig getTaskPerformerConfig()
    Returns the TaskPerformerConfig for this task performer.
    java.lang.String getTaskType()
    Returns the task type that this TaskPerformer can handle
    TaskResult performTask​(java.lang.String taskParams, java.lang.String taskInput)
    Execute the given task - this represents the "meat" of most TaskPerformer implementations.
    void setTaskPerformerConfig​(TaskPerformerConfig taskPerformerConfig)
    Sets the TaskPerformerConfig on this task performer.

  • Method Details

    • setTaskPerformerConfig

      void setTaskPerformerConfig​(TaskPerformerConfig taskPerformerConfig)
      Sets the TaskPerformerConfig on this task performer. This includes any parameterization of the behavior of this performer specified in that configuration
      Parameters:
      taskPerformerConfig - configuration for this task performer

    • performTask

      TaskResult performTask​(java.lang.String taskParams, java.lang.String taskInput)
      Execute the given task - this represents the "meat" of most TaskPerformer implementations. The TaskPerformer should perform its work and return a TaskResult to indicate the outcome.

      If this method throws an Exception, a RETRY will automatically be used which wraps the thrown exception.

      Parameters:
      taskParams - parameters supplied when task was created
      taskInput - the output of the task this task depends on
      Returns:
      the execution status

    • addToFailTransaction

      void addToFailTransaction​(java.lang.String taskParams, java.lang.String taskInput, java.lang.String reason)
      After a result of FAIL, this gives the TaskPerformer the opportunity to perform an action which may update the database. (In a typical failure scenario the transaction is rolled back, thus the need for a separate handler.)

      Note: This method is also called when a task moves from FAIL_PENDING to FAILED. Currently, implementations can restrict or modify execution by checking the task state in the method using GridTask.getState() from GridTaskContext.getGridTask(). A state of TaskState.RUNNING implies that the method was called through normal execution of the task; TaskState.FAIL_PENDING implies that it is being run administratively.

      Parameters:
      taskParams - parameters supplied when task was created
      taskInput - the output of the task this task depends on
      reason - a description of what caused the task to fail

    • addToRetryTransaction

      void addToRetryTransaction​(java.lang.String taskParams, java.lang.String taskInput, java.lang.String reason)
      After a result of RETRY, this gives the TaskPerformer the opportunity to perform an action which may update the database. (In a typical retry scenario the transaction is rolled back, thus the need for a separate handler.)
      Parameters:
      taskParams - parameters supplied when task was created
      taskInput - the output of the task this task depends on
      reason - a description of what caused the task to retry

    • getTaskType

      java.lang.String getTaskType()
      Returns the task type that this TaskPerformer can handle
      Returns:
      the task type that this TaskPerformer can handle

    • getTaskPerformerConfig

      TaskPerformerConfig getTaskPerformerConfig()
      Returns the TaskPerformerConfig for this task performer. This includes any parameterization of the behavior of this performer specified in that configuration.
      Returns:
      TaskPerformerConfig for this task performer