Package org.springframework.batch.core.partition.support

Class SimpleStepExecutionSplitter

java.lang.Object
org.springframework.batch.core.partition.support.SimpleStepExecutionSplitter
All Implemented Interfaces:
StepExecutionSplitter, org.springframework.beans.factory.InitializingBean
public class SimpleStepExecutionSplitter extends Object implements StepExecutionSplitter, org.springframework.beans.factory.InitializingBean
Generic implementation of StepExecutionSplitter that delegates to a Partitioner to generate ExecutionContext instances. Takes care of restartability and identifying the step executions from previous runs of the same job. The generated StepExecution instances have names that identify them uniquely in the partition. The name is constructed from a base (name of the target step) plus a suffix taken from the Partitioner identifiers, separated by a colon, e.g. {step1:partition0, step1:partition1, ...}.
Since:
2.0
Author:
Dave Syer, Mahmoud Ben Hassine

  • Constructor Details

    • SimpleStepExecutionSplitter

      public SimpleStepExecutionSplitter()
      Default constructor for convenience in configuration.

    • SimpleStepExecutionSplitter

      public SimpleStepExecutionSplitter(JobRepository jobRepository, boolean allowStartIfComplete, String stepName, Partitioner partitioner)
      Construct a SimpleStepExecutionSplitter from its mandatory properties.
      Parameters:
      jobRepository - the JobRepository
      allowStartIfComplete - flag specifying preferences on restart
      stepName - the target step name
      partitioner - a Partitioner to use for generating input parameters

  • Method Details

    • afterPropertiesSet

      public void afterPropertiesSet() throws Exception
      Check mandatory properties (step name, job repository and partitioner).
      Specified by:
      afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean
      Throws:
      Exception
      See Also:
      • InitializingBean.afterPropertiesSet()

    • setAllowStartIfComplete

      public void setAllowStartIfComplete(boolean allowStartIfComplete)
      Flag to indicate that the partition target step is allowed to start if an execution is complete. Defaults to the same value as the underlying step. Set this manually to override the underlying step properties.
      Parameters:
      allowStartIfComplete - the value to set
      See Also:

    • setJobRepository

      public void setJobRepository(JobRepository jobRepository)
      The job repository that will be used to manage the persistence of the delegate step executions.
      Parameters:
      jobRepository - the JobRepository to set

    • setPartitioner

      public void setPartitioner(Partitioner partitioner)
      The Partitioner that will be used to generate step execution meta data for the target step.
      Parameters:
      partitioner - the partitioner to set

    • setStepName

      public void setStepName(String stepName)
      The name of the target step that will be executed across the partitions. Mandatory with no default.
      Parameters:
      stepName - the step name to set

    • getStepName

      public String getStepName()
      Description copied from interface: StepExecutionSplitter
      The name of the step configuration that will be executed remotely. Remote workers are going to execute a the same step for each execution context in the partition.
      Specified by:
      getStepName in interface StepExecutionSplitter
      Returns:
      the name of the step that will execute the business logic
      See Also:

    • split

      public Set<StepExecution> split(StepExecution stepExecution, int gridSize) throws JobExecutionException
      Description copied from interface: StepExecutionSplitter
      Partition the provided StepExecution into a set of parallel executable instances with the same parent JobExecution. The grid size will be treated as a hint for the size of the collection to be returned. It may or may not correspond to the physical size of an execution grid.

      On a restart clients of the StepExecutionSplitter should expect it to reconstitute the state of the last failed execution and only return those executions that need to be restarted. Thus the grid size hint will be ignored on a restart.
      Specified by:
      split in interface StepExecutionSplitter
      Parameters:
      stepExecution - the StepExecution to be partitioned.
      gridSize - a hint for the splitter if the size of the grid is known
      Returns:
      a set of StepExecution instances for remote processing
      Throws:
      JobExecutionException - if the split cannot be made
      See Also:

    • isStartable

      protected boolean isStartable(StepExecution stepExecution, ExecutionContext context) throws JobExecutionException
      Check if a step execution is startable.
      Parameters:
      stepExecution - the step execution to check
      context - the execution context of the step
      Returns:
      true if the step execution is startable, false otherwise
      Throws:
      JobExecutionException - if unable to check if the step execution is startable