Package uk.ac.starlink.table

Class AccessRowSequence

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, RowData, RowSequence, uk.ac.starlink.util.Sequence
    public class AccessRowSequence
extends java.lang.Object
implements RowSequence
    RowSequence implementation based on a RowAccess.
    Since:
    24 Jul 2020
    Author:
    Mark Taylor

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Indicates that this sequence will not be required any more.
      static AccessRowSequence createInstance​(StarTable table)
      Constructs an AccessRowSequence based on a given table.
      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 advance 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

      • AccessRowSequence

        public AccessRowSequence​(RowAccess racc,
                         long nrow)
        Constructor.
        Parameters:
        racc - row access providing data access
        nrow - number of rows

    • Method Detail

      • next

        public boolean next()
             throws java.io.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:
        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 RowData
        Specified by:
        getCell in interface RowSequence
        Parameters:
        icol - column index
        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 RowData
        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 java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in interface RowSequence
        Throws:
        java.io.IOException

      • createInstance

        public static AccessRowSequence createInstance​(StarTable table)
                                        throws java.io.IOException
        Constructs an AccessRowSequence based on a given table.
        Parameters:
        table - table
        Returns:
        new row access
        Throws:
        java.io.IOException