uk.ac.starlink.fits

## Class ColFitsStarTable

- java.lang.Object
- - uk.ac.starlink.table.AbstractStarTable
  - - uk.ac.starlink.fits.ColFitsStarTable

- All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, StarTable

      public class ColFitsStarTable
      extends AbstractStarTable

  StarTable based on a single-row FITS BINTABLE which contains the data for an entire column in each cell of the table. The BINTABLE must be the first extension of a FITS file.

  Some instances of this class hang on to file descriptors. If you are in danger of running out of that resource before insstances are garbage collected, you can call the `close()` method to release them. Attempting to read data following such a call may result in an exception.

  Since:
    21 Jun 2006

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `ColFitsStarTable(DataSource datsrc, FitsHeader hdr, long dataPos, boolean force, WideFits wide)` Constructor.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `close()` The `AbstractStarTable` implementation of this method does nothing.
    `java.lang.Object` | `getCell(long irow, int icol)` The `AbstractStarTable` implementation of this method throws an `UnsupportedOperationException`, since unless otherwise provided there is no random access.
    `int` | `getColumnCount()` Returns the number of columns in this table.
    `ColumnInfo` | `getColumnInfo(int icol)` Returns the object describing the data in a given column.
    `java.lang.Object[]` | `getRow(long irow)` The `AbstractStarTable` implementation of this method constructs a row by repeated invocation of `AbstractStarTable.getCell(long, int)`.
    `RowAccess` | `getRowAccess()` Returns an object which can provide random access to this table's data, if random access is implemented.
    `long` | `getRowCount()` Returns the number of rows in this table, if known.
    `RowSequence` | `getRowSequence()` Returns an object which can iterate over all the rows in the table sequentially.
    `boolean` | `isRandom()` The `AbstractStarTable` implementation of this method returns `false`.

    - ### Methods inherited from class uk.ac.starlink.table.AbstractStarTable

      `checkedLongToInt, getColumnAuxDataInfos, getName, getParameters, getRowSplittable, getURL, setName, setParameters, setURL`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

    - ### Methods inherited from interface uk.ac.starlink.table.StarTable

      `getParameterByName, setParameter`

- - ### Constructor Detail

    - #### ColFitsStarTable

          public ColFitsStarTable(DataSource datsrc,
                                  FitsHeader hdr,
                                  long dataPos,
                                  boolean force,
                                  WideFits wide)
                           throws java.io.IOException

      Constructor.
      Parameters:
        `datsrc` - data source containing the FITS data
        `hdr` - header of the HDU containing the table
        `dataPos` - offset into `file` of the start of the data part of the HDU
        `force` - true to make a table if we possibly can, false to reject if it doesn't look very much like one
        `wide` - convention for representing extended columns; use null to avoid use of extended columns
      Throws:
        `java.io.IOException`

  - ### Method Detail

    - #### getColumnCount

          public int getColumnCount()

      Description copied from interface: `StarTable`
      Returns the number of columns in this table.
      Specified by:
        `getColumnCount` in interface `StarTable`
      Specified by:
        `getColumnCount` in class `AbstractStarTable`
      Returns:
        the number of columns

    - #### getRowCount

          public long getRowCount()

      Description copied from interface: `StarTable`
      Returns the number of rows in this table, if known. If the number of rows cannot be (easily) determined, a value of -1 will be returned.
      Specified by:
        `getRowCount` in interface `StarTable`
      Specified by:
        `getRowCount` in class `AbstractStarTable`
      Returns:
        the number of rows, or -1

    - #### isRandom

          public boolean isRandom()

      Description copied from class: `AbstractStarTable`
      The `AbstractStarTable` implementation of this method returns `false`.
      Specified by:
        `isRandom` in interface `StarTable`
      Overrides:
        `isRandom` in class `AbstractStarTable`
      Returns:
        `true` if table random access methods are available

    - #### getColumnInfo

          public ColumnInfo getColumnInfo(int icol)

      Description copied from interface: `StarTable`
      Returns the object describing the data in a given column.
      Specified by:
        `getColumnInfo` in interface `StarTable`
      Specified by:
        `getColumnInfo` in class `AbstractStarTable`
      Parameters:
        `icol` - the column for which header information is required
      Returns:
        a ValueInfo object for column `icol`

    - #### getCell

          public java.lang.Object getCell(long irow,
                                          int icol)
                                   throws java.io.IOException

      Description copied from class: `AbstractStarTable`
      The `AbstractStarTable` implementation of this method throws an `UnsupportedOperationException`, since unless otherwise provided there is no random access.
      Specified by:
        `getCell` in interface `StarTable`
      Overrides:
        `getCell` in class `AbstractStarTable`
      Parameters:
        `irow` - the index of the cell's row
        `icol` - the index of the cell's column
      Returns:
        the contents of this cell
      Throws:
        `java.io.IOException` - if there is an error reading the data

    - #### getRow

          public java.lang.Object[] getRow(long irow)
                                    throws java.io.IOException

      Description copied from class: `AbstractStarTable`
      The `AbstractStarTable` implementation of this method constructs a row by repeated invocation of `AbstractStarTable.getCell(long, int)`.
      Specified by:
        `getRow` in interface `StarTable`
      Overrides:
        `getRow` in class `AbstractStarTable`
      Parameters:
        `irow` - the index of the row to retrieve
      Returns:
        an array of the objects in each cell in row `irow`
      Throws:
        `java.io.IOException` - if there is an error reading the data

    - #### getRowSequence

          public RowSequence getRowSequence()
                                     throws java.io.IOException

      Description copied from interface: `StarTable`
      Returns an object which can iterate over all the rows in the table sequentially. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
      Specified by:
        `getRowSequence` in interface `StarTable`
      Specified by:
        `getRowSequence` in class `AbstractStarTable`
      Returns:
        new RowSequence
      Throws:
        `java.io.IOException` - if there is an error providing access

    - #### getRowAccess

          public RowAccess getRowAccess()
                                 throws java.io.IOException

      Description copied from interface: `StarTable`
      Returns an object which can provide random access to this table's data, if random access is implemented. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
      Specified by:
        `getRowAccess` in interface `StarTable`
      Overrides:
        `getRowAccess` in class `AbstractStarTable`
      Returns:
        new RowAccess
      Throws:
        `java.io.IOException` - if there is an error setting up access

    - #### close

          public void close()
                     throws java.io.IOException

      Description copied from class: `AbstractStarTable`
      The `AbstractStarTable` implementation of this method does nothing.
      Specified by:
        `close` in interface `java.io.Closeable`
      Specified by:
        `close` in interface `java.lang.AutoCloseable`
      Specified by:
        `close` in interface `StarTable`
      Overrides:
        `close` in class `AbstractStarTable`
      Throws:
        `java.io.IOException`