uk.ac.starlink.table
Class WrapperRowSequence

java.lang.Object
  extended by uk.ac.starlink.table.WrapperRowSequence
All Implemented Interfaces:
RowSequence

public class WrapperRowSequence
extends java.lang.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.

See Also:
WrapperStarTable

Field Summary
protected  RowSequence baseSeq
           
 
Constructor Summary
WrapperRowSequence(RowSequence baseSeq)
          Constructs a new RowSequence based on a given one.
 
Method Summary
 void close()
          Indicates that this sequence will not be required any more.
 java.lang.Object getCell(int icol)
          Returns the contents of a cell in the current row.
 java.lang.Object[] getRow()
          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 next()
          Attempts to advances the current row to the next one.
 java.lang.String toString()
          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 Detail

baseSeq

protected RowSequence baseSeq
Constructor Detail

WrapperRowSequence

public WrapperRowSequence(RowSequence baseSeq)
Constructs a new RowSequence based on a given one.

Parameters:
baseSeq - the base row sequence
Method Detail

next

public boolean next()
             throws java.io.IOException
Description copied from interface: RowSequence
Attempts to advances 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
Returns:
true iff this sequence has been advanced to the next row
Throws:
java.io.IOException - if there is some error

getCell

public java.lang.Object getCell(int icol)
                         throws java.io.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 RowSequence
Returns:
the contents of cell icol in the current row
Throws:
java.io.IOException - if there is an error reading the data

getRow

public java.lang.Object[] getRow()
                          throws java.io.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 RowSequence
Returns:
an array of the objects in each cell in row irow
Throws:
java.io.IOException - if there is an error reading the data

close

public void close()
           throws java.io.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 RowSequence
Throws:
java.io.IOException

toString

public java.lang.String toString()
Returns an indication of the wrapper structure of this sequence.

Overrides:
toString in class java.lang.Object
Returns:
string representation