Class WrapperRowSequence

java.lang.Object
uk.ac.starlink.table.WrapperRowSequence
All Implemented Interfaces:
Closeable, AutoCloseable, RowData, RowSequence, uk.ac.starlink.util.Sequence
Direct Known Subclasses:
MappingRowSplittable

public class WrapperRowSequence extends Object implements RowSequence
RowSequence which wraps another RowSequence. This class acts as a wrapper around an existing 'base' RowSequence object; all its methods are implemented by forwarding them to the corresponding methods of that base sequence.

This class is provided so that it can be extended by subclasses which modify the view of the base sequence in useful ways.

Author:
Mark Taylor (Starlink)
See Also:
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected final RowSequence
     
  • Constructor Summary

    Constructors
    Constructor
    Description
    Constructs a new RowSequence based on a given one.
    Constructs a new RowSequence based on a given one but with a supplied data access implementation.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Indicates that this sequence will not be required any more.
    getCell(int icol)
    Returns the contents of a cell in the current row.
    Returns the contents of the current table row, as an array with the same number of elements as there are columns in this table.
    boolean
    Attempts to advance the current row to the next one.
    Returns an indication of the wrapper structure of this sequence.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
  • Field Details

  • Constructor Details

    • WrapperRowSequence

      public WrapperRowSequence(RowSequence baseSeq)
      Constructs a new RowSequence based on a given one.
      Parameters:
      baseSeq - the base row sequence
    • WrapperRowSequence

      public WrapperRowSequence(RowSequence baseSeq, RowData data)
      Constructs a new RowSequence based on a given one but with a supplied data access implementation.
      Parameters:
      baseSeq - the base row access
      data - RowData object whose methods will be used to implement the getCell and getRow methods
  • Method Details

    • next

      public boolean next() throws IOException
      Description copied from interface: RowSequence
      Attempts to advance the current row to the next one. If true is returned the attempt has been successful, and if false is returned there are no more rows in this sequence. Since the initial position of a RowSequence is before the first row, this method must be called before current row data can be accessed using the RowSequence.getCell(int) or RowSequence.getRow() methods.
      Specified by:
      next in interface RowSequence
      Specified by:
      next in interface uk.ac.starlink.util.Sequence
      Returns:
      true iff this sequence has been advanced to the next row
      Throws:
      IOException - if there is some error
    • getCell

      public Object getCell(int icol) throws IOException
      Description copied from interface: RowSequence
      Returns the contents of a cell in the current row. The class of the returned object should be the same as, or a subclass of, the class returned by getColumnInfo(icol).getContentClass(). An unchecked exception will be thrown if there is no current row (next has not yet been called).
      Specified by:
      getCell in interface RowData
      Specified by:
      getCell in interface RowSequence
      Parameters:
      icol - column index
      Returns:
      the contents of cell icol in the current row
      Throws:
      IOException - if there is an error reading the data
    • getRow

      public Object[] getRow() throws IOException
      Description copied from interface: RowSequence
      Returns the contents of the current table row, as an array with the same number of elements as there are columns in this table. An unchecked exception will be thrown if there is no current row (next has not yet been called).
      Specified by:
      getRow in interface RowData
      Specified by:
      getRow in interface RowSequence
      Returns:
      an array of the objects in each cell in row irow
      Throws:
      IOException - if there is an error reading the data
    • close

      public void close() throws IOException
      Description copied from interface: RowSequence
      Indicates that this sequence will not be required any more. This should release resources associated with this object. The effect of calling any of the other methods following a close is undefined.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface RowSequence
      Throws:
      IOException
    • toString

      public String toString()
      Returns an indication of the wrapper structure of this sequence.
      Overrides:
      toString in class Object
      Returns:
      string representation