Declaring the Capabilities of the Java code (Java Integration stage in DataStage)

The Capabilities class defines the capabilities of your Java™ code by encapsulating a list of attributes and parameters.

The following is a list of the available methods that the Capabilities class provides. For details about the methods, see the Javadoc information in the Java Integration stage API documentation.

getMinimumInputLinkCount()
getMaximumInputLinkCount()
getMinimumOutputStreamLinkCount()
getMaximumOutputStreamLinkCount()
getMinimumRejectLinkCount()
getMaximumRejectLinkCount()
getColumnTransferBehavior()
isWaveGenerator()
isRunOnConductor()
setMinumumInputLinkCount()
setMaximumInputLinkCount()
setMinimumOutputStreamLinkCount()
setMaximumOutputStreamLinkCount()
setMinimumRejectLinkCount()
setMaximumRejectLinkCount()
setIsWaveGenerator()
setColumnTransferBehavior()
setIsRunOnConductor()

Right after instantiating your Processor code, the Java Integration stage invokes the getCapabilities() method in your Processor code to get its associated Capabilities object to determine whether your Java code can be run in the current job design.

By overriding the getCapabilities() method in the Processor class, your Java code can customize the values of the capabilities to address your Java code, and pass it to the Java Integration stage.

The following example shows that your Java code only accepts the case of single input link.

public Capabilities getCapabilities()
{
  Capabilities capabilities = new Capabilities();
  capabilities.setMinimumInputLinkCount(1);
  capabilities.setMaximumInputLinkCount(1);
  capabilities.setMaximumOutputStreamLinkCount(0);
  capabilities.setMaximumRejectLinkCount(0);
  return capabilities;
}

The job ends if the current job design does not fit the specified capabilities.

The following code provides the functionality which is equivalent to the first example. The Java Integration stage will compare the number of links attached to the stage with the limits specified by the implementation of the getCapabilities() method. If the number of links it outside of the specified bounds, then the Java Integration stage will send an appropriate message to the job log and will abort the job.

package samples;

import com.ibm.is.cc.javastage.api.*;

public class ReworkedSimplePeek extends Processor
{
  private InputLink m_inputLink;

  public Capabilities getCapabilities()
  {
    Capabilities capabilities = new Capabilities();
    capabilities.setMinimumInputLinkCount(1);
    capabilities.setMaximumInputLinkCount(1);
    capabilities.setMaximumOutputStreamLinkCount(0);
    capabilities.setMaximumRejectLinkCount(0);
    return capabilities;
  }

  public boolean validateConfiguration(
    Configuration configuration, boolean isRuntime)throws Exception
  {
    m_inputLink = configuration.getInputLink(0);     
    return true;   
  }

  public void process() throws Exception
  {
    do
{
      InputRecord inputRecord = m_inputLink.readRecord();
      if (inputRecord == null)
      { 
         // No more input. Your code must return from process() method.
         break;
      }

      for (int i = 0; i < m_inputLink.getColumnCount(); i++) 
      { 
         Object value = inputRecord.getValue(i);
         Logger.information(value.toString());
      }
    } 
    while (true);
  }
}