com.marklogic.client.datamovement

Class UrisToWriterListener

java.lang.Object

com.marklogic.client.datamovement.UrisToWriterListener

All Implemented Interfaces:

BatchListener<QueryBatch>, QueryBatchListener

public class UrisToWriterListener
extends Object
implements QueryBatchListener

Facilitates writing uris to a file when necessary because setting merge timestamp and withConsistentSnapshot is not an option, but you need to run DeleteListener or ApplyTransformListener.

Example writing uris to disk then running a delete:

FileWriter writer = new FileWriter("uriCache.txt");
QueryBatcher getUris = dataMovementManager.newQueryBatcher(query)
  .withBatchSize(5000)
  .onUrisReady( new UrisToWriterListener(writer) )
  .onQueryFailure(exception -> exception.printStackTrace());
JobTicket getUrisTicket = dataMovementManager.startJob(getUris);
getUris.awaitCompletion();
dataMovementManager.stopJob(getUrisTicket);
writer.flush();
writer.close();

// now we have the uris, let's step through them
BufferedReader reader = new BufferedReader(new FileReader("uriCache.txt"));
QueryBatcher performDelete = dataMovementManager.newQueryBatcher(reader.lines().iterator())
  .onUrisReady(new DeleteListener())
  .onQueryFailure(exception -> exception.printStackTrace());
JobTicket ticket = dataMovementManager.startJob(performDelete);
performDelete.awaitCompletion();
dataMovementManager.stopJob(ticket);

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	UrisToWriterListener.OutputListener

Constructor Summary

Constructors

Constructor and Description
UrisToWriterListener(Writer writer)

Method Summary

Modifier and Type	Method and Description
UrisToWriterListener	onBatchFailure(BatchFailureListener<Batch<String>> listener) When a batch fails or a callback throws an Exception, run this listener code.
UrisToWriterListener	onGenerateOutput(UrisToWriterListener.OutputListener listener)
void	processEvent(QueryBatch batch) The method called by QueryBatcher or WriteBatcher to run your custom code on this batch.
UrisToWriterListener	withRecordPrefix(String prefix)
UrisToWriterListener	withRecordSuffix(String suffix)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UrisToWriterListener

public UrisToWriterListener(Writer writer)

Method Detail

processEvent

public void processEvent(QueryBatch batch)

Description copied from interface: QueryBatchListener

The method called by QueryBatcher or WriteBatcher to run your custom code on this batch. You usually implement this as a lambda expression.

For example, see the lambda expression passed to onUrisReady:

QueryBatcher qhb = dataMovementManager.newQueryBatcher(query)
    .withBatchSize(1000)
    .withThreadCount(20)
    .onUrisReady(batch -> {
        for ( String uri : batch.getItems() ) {
            if ( uri.endsWith(".txt") ) {
                batch.getClient().newDocumentManager().delete(uri);
            }
        }
    })
    .onQueryFailure(queryBatchException -> queryBatchException.printStackTrace());
JobTicket ticket = dataMovementManager.startJob(qhb);
qhb.awaitCompletion();
dataMovementManager.stopJob(ticket);

Specified by:

processEvent in interface BatchListener<QueryBatch>

Specified by:

processEvent in interface QueryBatchListener

Parameters:

batch - the batch of uris and some metadata about the current status of the job

withRecordSuffix

public UrisToWriterListener withRecordSuffix(String suffix)

withRecordPrefix

public UrisToWriterListener withRecordPrefix(String prefix)

onGenerateOutput

public UrisToWriterListener onGenerateOutput(UrisToWriterListener.OutputListener listener)

onBatchFailure

public UrisToWriterListener onBatchFailure(BatchFailureListener<Batch<String>> listener)

When a batch fails or a callback throws an Exception, run this listener code. Multiple listeners can be registered with this method.

Parameters:

listener - the code to run when a failure occurs

Returns:

this instance for method chaining