Class RandomRowSequence

  • All Implemented Interfaces:
    RowSequence

    public class RandomRowSequence
    extends java.lang.Object
    implements RowSequence
    An implementation of RowSequence which obtains its data from a random-access StarTable object.
    • Constructor Summary

      Constructors 
      Constructor Description
      RandomRowSequence​(StarTable startab)
      Constructs a RowSequence from a StarTable which must offer random access and know its number of rows.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      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.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • RandomRowSequence

        public RandomRowSequence​(StarTable startab)
        Constructs a RowSequence from a StarTable which must offer random access and know its number of rows.
        Parameters:
        startab - the StarTable object providing the data
        Throws:
        java.lang.IllegalArgumentException - if startab.isRandom()==false or startab.getRowCount()<0
    • Method Detail

      • next

        public boolean next()
        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
      • 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
      • 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
      • close

        public void close()
        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