Class AbstractReader

Method Details

• 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 DataReader

• isFieldNamesInFirstRow

  public boolean isFieldNamesInFirstRow()

  Indicates if the first row holds the field names instead of data (default is false).

• setFieldNamesInFirstRow

  public AbstractReader setFieldNamesInFirstRow(boolean fieldNamesInFirstRow)

  Indicates if the first row holds the field names instead of data (default is false); must be called before open().

• getFieldNames

  public String[] getFieldNames()

  Returns a copy of the field names that were set or read from the first row, or an empty array if there are none yet.

• setFieldNames

  public AbstractReader setFieldNames(String... fieldNames)

  Sets the names given to each record's fields, taking precedence over names in the first row; must be called before open().

• setFieldNames

  public AbstractReader setFieldNames(Collection<String> fieldNames)

  Sets the names given to each record's fields, taking precedence over names in the first row; must be called before open().

• setStartingRow

  public AbstractReader setStartingRow(int startingRow)

  Sets the 0-based index of the first row to read; earlier rows are skipped when the reader is opened (default is 0).

• getStartingRow

  public int getStartingRow()

  Returns the 0-based index of the first row to read; earlier rows are skipped when the reader is opened (default is 0).

• setLastRow

  public AbstractReader setLastRow(int lastRow)

  Sets the 0-based index of the last row to read or -1 to read to the end (default is -1).

• getLastRow

  public int getLastRow()

  Returns the 0-based index of the last row to read or -1 to read to the end (default is -1).

• setSkipEmptyRows

  public AbstractReader setSkipEmptyRows(boolean skipEmptyRows)

  Indicates that rows with only null values should not be returned by the reader (default is false).

• isSkipEmptyRows

  public boolean isSkipEmptyRows()

  Indicates that rows with only null values should not be returned by the reader (default is false).

• 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

• read

  public Record read() throws DataException

  Description copied from class: DataReader

  Reads the next record from this DataReader and increases the record-count by 1. This method will first read any pushed (DataReader.push(Record)) records before reading from the underlying source.

  If no record is available, null will be returned. This method blocks until a record is available, the end of the stream is reached, or an exception is thrown.

  Any exception raised while reading will be converted to a DataException using DataObject.exception(Throwable).

  Subclasses generally do not need to override this method, instead they should implement DataReader.readImpl().

  Overrides:

  read in class DataReader

  Throws:

  DataException

  See Also:

  • DataReader.push(Record)
  • DataReader.peek(int)
  • DataReader.read()

• readImpl

  protected Record readImpl() throws Throwable

  Description copied from class: DataReader

  Overridden by subclasses to read the next record from this DataReader. The default implementation of DataReader.read() now insures that this method will not be called again after it returns a null.

  If no record is available, null will be returned.

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

  • Return null exactly once to signal end-of-stream.
  • Do not call this method directly — DataReader.read() is the template method that wraps exceptions, increments the record count, and tracks lineage.
  • Do not call DataEndpoint.incrementRecordCount() here; DataReader.read() already does.
  • Throw raw exceptions; DataReader.read() wraps them via exception(throwable).

  Specified by:

  readImpl in class DataReader

  Throws:

  Throwable

• fillRecord

  protected abstract boolean fillRecord(Record record) throws Throwable

  Populates the given record with the next row's values; returns false at the end of the input.

  Throws:

  Throwable