Class ProxyWriter

Method Details

• map

  public static ProxyWriter map(DataWriter Writer, Function<Record,Record> mapper) throws Throwable

  Wraps the writer in a proxy that passes each record through the mapper before writing it; a null result drops the record.

  Throws:

  Throwable

• map

  public static ProxyWriter map(DataWriter writer, BiFunction<ProxyWriter,Record,Record> mapper) throws Throwable

  Wraps the writer in a proxy that passes itself and each record to the mapper before writing; a null result drops the record.

  Throws:

  Throwable

• getNestedWriter

  public DataWriter getNestedWriter()

  Description copied from class: DataWriter

  Returns the DataWriter held inside this one or null if there isn't one.

  Overrides:

  getNestedWriter in class DataWriter

• setNestedDataWriter

  protected void setNestedDataWriter(DataWriter nestedDataWriter)

  Make sure to close old target and open the new one or call setNestedDataWriter(DataWriter, boolean) with true.

• setNestedDataWriter

  protected void setNestedDataWriter(DataWriter nestedDataWriter, boolean manageLifecycle) throws DataException

  Replaces the nested writer; with manageLifecycle the old writer is closed and, if this proxy is open, the new one is opened.

  Throws:

  DataException

• available

  public int available() throws DataException

  Description copied from class: DataWriter

  Returns the number of records that can probably be written without blocking.

  Overrides:

  available in class DataWriter

  Throws:

  DataException

• open

  public void open() throws DataException

  Description copied from class: DataEndpoint

  Makes this endpoint ready for reading or writing.

  Overrides:

  open in class DataEndpoint

  Throws:

  DataException

• close

  public void close() throws DataException

  Description copied from class: DataEndpoint

  Indicates that this endpoint has finished reading or writing.

  Overrides:

  close in class DataEndpoint

  Throws:

  DataException

• interceptRecord

  protected Record interceptRecord(Record record) throws Throwable

  Overridden by subclasses to transform, drop, or observe a record on its way through this proxy.

  Contract for subclasses (see also docs/authoring/ProxyWriter.md):

  • Return the record (possibly modified) to forward it to the nested DataWriter.
  • Return null to drop the record; the framework will not write it downstream.
  • Throw to fail the pipeline; the framework wraps the throwable in a DataException with .setRecord(record).
  • The nested DataWriter is opened and closed for you; do not write to it here.
  • Do not call DataEndpoint.incrementRecordCount() here.

  Throws:

  Throwable

• writeImpl

  protected void writeImpl(Record record) throws Throwable

  Description copied from class: DataWriter

  Overridden by subclasses to write the specified record to this DataWriter.

  Contract for subclasses (see also docs/authoring/DataWriter.md):

  • Do not call this method directly — DataWriter.write(Record) is the template method that wraps exceptions, increments the record count, and attaches the offending record to thrown DataExceptions.
  • Do not call DataEndpoint.incrementRecordCount() here; DataWriter.write(Record) already does.
  • Throw raw exceptions; DataWriter.write(Record) wraps them via exception(throwable).setRecord(record).

  Specified by:

  writeImpl in class DataWriter

  Throws:

  Throwable

• addExceptionProperties

  public DataException addExceptionProperties(DataException exception)

  Description copied from class: Endpoint

  Adds this endpoint's current state to a DataException. Since this method is called whenever an exception is thrown, subclasses should override it to add their specific information.

  Overrides:

  addExceptionProperties in class DataWriter