Documentation Version: 3.4 - Publication Date : Dec 24, 2014

Abstract Entry Processor

You can use the AbstractEntryProcessor when the same processing will be performed both on the primary and backup map entries (i.e. the same logic applies to them). If you use EntryProcessor, you need to apply the same logic to the backup entries separately. The AbstractEntryProcessor class makes this primary/backup processing easier.

Please see the example code below.

public abstract class AbstractEntryProcessor <K, V>
    implements EntryProcessor <K, V> {

  private final EntryBackupProcessor <K,V> entryBackupProcessor;
  public AbstractEntryProcessor() {
    this(true);
  }

  public AbstractEntryProcessor(boolean applyOnBackup) {
    if ( applyOnBackup ) {
      entryBackupProcessor = new EntryBackupProcessorImpl();
    } else {
      entryBackupProcessor = null;
    }
  } 

  @Override
  public abstract Object process(Map.Entry<K, V> entry);

  @Override
  public final EntryBackupProcessor <K, V> getBackupProcessor() {
    return entryBackupProcessor;
  }

  private class EntryBackupProcessorImpl implements EntryBackupProcessor <K,V>{
    @Override
    public void processBackup(Map.Entry<K, V> entry) {
      process(entry); 
    }
  }    
}

In the above example, the method getBackupProcessor returns an EntryBackupProcessor instance. This means the same processing will be applied to both the primary and backup entries. If you want to apply the processing only upon the primary entries, then make the getBackupProcessor method return null.