How to use org.apache.hive.hcatalog.messaging

/**
 * Getter for MessageFactory instance.
 */
public static MessageFactory getInstance() {
 if (instance == null) {
  instance = getInstance(HCAT_MESSAGE_FACTORY_IMPL);
 }
 return instance;
}

 @Override
 public HCatEventMessage checkValid() {
  if (getTable() == null)
   throw new IllegalStateException("Table name unset.");
  return super.checkValid();
 }
}

@Override
public HCatEventMessage checkValid() {
 if (getTable() == null) throw new IllegalStateException("Table name unset.");
 return super.checkValid();
}

switch (HCatEventMessage.EventType.valueOf(eventTypeString)) {
case CREATE_DATABASE:
 return getCreateDatabaseMessage(messageBody);
case DROP_DATABASE:
 return getDropDatabaseMessage(messageBody);
case CREATE_TABLE:
 return getCreateTableMessage(messageBody);
case ALTER_TABLE:
 return getAlterTableMessage(messageBody);
case DROP_TABLE:
 return getDropTableMessage(messageBody);
case ADD_PARTITION:
 return getAddPartitionMessage(messageBody);
case ALTER_PARTITION:
 return getAlterPartitionMessage(messageBody);
case DROP_PARTITION:
 return getDropPartitionMessage(messageBody);
case CREATE_FUNCTION:
 return getCreateFunctionMessage(messageBody);
case DROP_FUNCTION:
 return getDropFunctionMessage(messageBody);
case INSERT:
 return getInsertMessage(messageBody);
default:
 throw new IllegalArgumentException("Unsupported event-type: " + eventTypeString);

 @Override
 public HCatEventMessage checkValid() {
  if (getTable() == null)
   throw new IllegalStateException("Table name unset.");
  if (getPartitions() == null)
   throw new IllegalStateException("Partition-list unset.");
  return super.checkValid();
 }
}

 @Override
 public HCatEventMessage checkValid() {
  if (getTable() == null)
   throw new IllegalStateException("Table name unset.");
  if (getPartitions() == null)
   throw new IllegalStateException("Partition-list unset.");
  return super.checkValid();
 }
}

 @Override
 public HCatEventMessage checkValid() {
  if (getTable() == null) throw new IllegalStateException("Table name unset.");
  if (getKeyValues() == null) throw new IllegalStateException("Partition values unset");
  return super.checkValid();
 }
}

public AlterTableReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event, HCatConstants.HCAT_ALTER_TABLE_EVENT);
 alterTableMessage = messageFactory.getDeserializer().getAlterTableMessage(event.getMessage());
}

public DropDatabaseReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event, HCatConstants.HCAT_DROP_DATABASE_EVENT);
 dropDatabaseMessage = messageFactory.getDeserializer().getDropDatabaseMessage(event.getMessage());
}

public CreateTableReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event, HCatConstants.HCAT_CREATE_TABLE_EVENT);
 createTableMessage = messageFactory.getDeserializer().getCreateTableMessage(event.getMessage());
}

public AlterPartitionReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event,HCatConstants.HCAT_ALTER_PARTITION_EVENT);
 alterPartitionMessage = messageFactory.getDeserializer().getAlterPartitionMessage(event.getMessage());
}

public DropPartitionReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event, HCatConstants.HCAT_DROP_PARTITION_EVENT);
 dropPartitionMessage = messageFactory.getDeserializer().getDropPartitionMessage(event.getMessage());
}

public InsertReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event, HCatConstants.HCAT_INSERT_EVENT);
 insertMessage = messageFactory.getDeserializer().getInsertMessage(event.getMessage());
}

public DropTableReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event, HCatConstants.HCAT_DROP_TABLE_EVENT);
 dropTableMessage = messageFactory.getDeserializer().getDropTableMessage(event.getMessage());
}

public AddPartitionReplicationTask(HCatNotificationEvent event) {
 super(event);
 validateEventType(event,HCatConstants.HCAT_ADD_PARTITION_EVENT);
 addPartitionMessage = messageFactory.getDeserializer().getAddPartitionMessage(event.getMessage());
}

 @Override
 public HCatEventMessage checkValid() {
  if (getTable() == null)
   throw new IllegalStateException("Table name unset.");
  return super.checkValid();
 }
}

 @Override
 public HCatEventMessage checkValid() {
  if (getTable() == null)
   throw new IllegalStateException("Table name unset.");
  return super.checkValid();
 }
}

public abstract MessageDeserializer getDeserializer();

public boolean needsStagingDirs(){
 // we need staging directories as long as a single partition needed addition
 return (!addPartitionMessage.getPartitions().isEmpty());
}

@Override
public void onAlterPartition(AlterPartitionEvent ape) throws MetaException {
 if (ape.getStatus()) {
  Partition before = ape.getOldPartition();
  Partition after = ape.getNewPartition();
  String topicName = getTopicName(ape.getTable());
  send(messageFactory.buildAlterPartitionMessage(ape.getTable(),before, after,
      ape.getWriteId()), topicName);
 }
}