Package com.streambase.liveview.client

Class SnapshotQueryListener

java.lang.Object
com.streambase.liveview.client.SnapshotQueryListener
All Implemented Interfaces:
QueryListener, SnapshotResult, Closeable, AutoCloseable, EventListener
public final class SnapshotQueryListener extends Object implements SnapshotResult, QueryListener
A Convenience implementation of QueryListener that provides a pull based iterator pattern for iterating over snapshot queries. This should be used with snapshot queries only. Snapshots that hit the row limit are ended without any special notification.

  • Constructor Details

    • SnapshotQueryListener

      public SnapshotQueryListener()

    • SnapshotQueryListener

      public SnapshotQueryListener(int dataQueueCapacity)

  • Method Details

    • getFields

      public List<Schema.Field> getFields() throws LiveViewException
      Retrieves the fields describing the tuples that will be returned.
      Specified by:
      getFields in interface SnapshotResult
      Returns:
      the fields describing the tuples
      Throws:
      LiveViewException - if exception occurs on the Query

    • hasNext

      public boolean hasNext() throws LiveViewException
      See if there are more tuples to retrieve. If there are not currently any Tuples waiting to be read, this will block until either the next Tuple or the Snapshot end arrives.
      Specified by:
      hasNext in interface SnapshotResult
      Returns:
      true if more tuples exist in result
      Throws:
      LiveViewException

    • next

      public Tuple next() throws LiveViewException
      Retrieves the next tuple in the result. If there are not currently any Tuples waiting to be read, this will block until either the next Tuple or the Snapshot end arrives.
      Specified by:
      next in interface SnapshotResult
      Returns:
      the next tuple
      Throws:
      LiveViewException - if exception occurs on the Query

    • tupleAdded

      public void tupleAdded(TupleAddedEvent event)
      Event when a new tuple is added to the result.
      Specified by:
      tupleAdded in interface QueryListener
      Parameters:
      event - add event

    • tupleUpdated

      public void tupleUpdated(TupleUpdatedEvent event)
      Event when an existing tuple in the result is updated.
      Specified by:
      tupleUpdated in interface QueryListener
      Parameters:
      event - update event

    • tupleRemoved

      public void tupleRemoved(TupleRemovedEvent event)
      Event when an existing tuple is removed from the result.
      Specified by:
      tupleRemoved in interface QueryListener
      Parameters:
      event - remove event

    • snapshotBegin

      public void snapshotBegin(BeginSnapshotEvent event)
      Event to indicate the start of the result snapshot. This is the first method called when a query starts returning results, but this method is also called to indicate a reset (a complete restart of the query.)
      Specified by:
      snapshotBegin in interface QueryListener
      Parameters:
      event - snapshot begin

    • snapshotEnd

      public void snapshotEnd(EndSnapshotEvent event)
      Event to indicate the query snapshot is complete.
      Specified by:
      snapshotEnd in interface QueryListener
      Parameters:
      event - snapshot end

    • exceptionRaised

      public void exceptionRaised(QueryExceptionEvent event)
      Event when an exception occurs during the query. Since 1.3, reaching the row limit is considered an exception.
      Specified by:
      exceptionRaised in interface QueryListener
      Parameters:
      event - exception event

    • queryClosed

      public void queryClosed(QueryClosedEvent event)
      Event when a query being listened to is closed.
      Specified by:
      queryClosed in interface QueryListener
      Parameters:
      event - query closed event

    • setQuery

      public void setQuery(Query queryImpl)

    • close

      public void close()
      Description copied from interface: SnapshotResult
      closes any resource associated with the snapshot result
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface SnapshotResult

    • deleteBegin

      public void deleteBegin(BeginDeleteEvent event)
      Description copied from interface: QueryListener
      Event to indicate the start of delete query.
      Specified by:
      deleteBegin in interface QueryListener
      Parameters:
      event - delete begin

    • deleteEnd

      public void deleteEnd(EndDeleteEvent event)
      Description copied from interface: QueryListener
      Event to indicate the delete query is complete.
      Specified by:
      deleteEnd in interface QueryListener
      Parameters:
      event - delete end