Package uk.ac.starlink.fits

Class StandardFitsTableSerializer

  • All Implemented Interfaces:
    FitsTableSerializer
    Direct Known Subclasses:
    VariableFitsTableSerializer
    public class StandardFitsTableSerializer
extends java.lang.Object
implements FitsTableSerializer
    Class which knows how to do the various bits of serializing a StarTable to FITS BINTABLE format. A normal (row-oriented) organisation of the data is used. Array-valued columns are all written as fixed size arrays. This class does the hard work for FitsTableWriter.

    When writing tables that are marked up using the headers defined in HealpixTableInfo, this serializer will attempt to insert FITS headers corresponding to the HEALPix-FITS convention.

    Author:
    Mark Taylor (Starlink)
    See Also:
    HEALPix-FITS convention

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String getBadValue​(int icol)
      Returns the bad value (text of the TNULLnn card), if any, used for a given column.
      FitsTableSerializerConfig getConfig()
      Returns the configuration information for this serializer.
      int[] getDimensions​(int icol)
      Returns the dimensions of the items which will be output for a given column.
      char getFormatChar​(int icol)
      Returns the FITS TFORM letter which describes the type of data output for a given column.
      CardImage[] getHeader()
      Returns header cards suitable for the HDU which will contain the table.
      protected CardImage[] getHealpixHeaders​(uk.ac.starlink.table.HealpixTableInfo hpxInfo)
      Returns FITS headers specific for a table containing a HEALPix map.
      long getRowCount()
      Returns the number of rows which will be output.
      void writeData​(java.io.DataOutput strm)
      Writes the HDU data for the table to an output stream.
      long writeDataOnly​(java.io.DataOutput strm)
      Writes the table data content without any trailing padding.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • StandardFitsTableSerializer

        public StandardFitsTableSerializer​(FitsTableSerializerConfig config,
                                   uk.ac.starlink.table.StarTable table)
                            throws java.io.IOException
        Constructor.
        Parameters:
        config - configuration
        table - table to serialize
        Throws:
        java.io.IOException - if it won't be possible to write the given table

    • Method Detail

      • getConfig

        public FitsTableSerializerConfig getConfig()
        Returns the configuration information for this serializer.
        Returns:
        config

      • getHeader

        public CardImage[] getHeader()
        Description copied from interface: FitsTableSerializer
        Returns header cards suitable for the HDU which will contain the table. Additional metadata and an END marker will be added after these cards, so the returned array must not contain the END card.
        Specified by:
        getHeader in interface FitsTableSerializer
        Returns:
        header cards

      • writeData

        public void writeData​(java.io.DataOutput strm)
               throws java.io.IOException
        Description copied from interface: FitsTableSerializer
        Writes the HDU data for the table to an output stream.
        Specified by:
        writeData in interface FitsTableSerializer
        Parameters:
        strm - destination stream
        Throws:
        java.io.IOException

      • writeDataOnly

        public long writeDataOnly​(java.io.DataOutput strm)
                   throws java.io.IOException
        Writes the table data content without any trailing padding.
        Parameters:
        strm - destination stream
        Returns:
        number of bytes written
        Throws:
        java.io.IOException

      • getFormatChar

        public char getFormatChar​(int icol)
        Description copied from interface: FitsTableSerializer
        Returns the FITS TFORM letter which describes the type of data output for a given column. This is as described by the FITS standard - 'J' for 4-byte integer, 'A' for characters, etc. If the column is not being output, (char)0 will be returned.
        Specified by:
        getFormatChar in interface FitsTableSerializer
        Parameters:
        icol - column to query
        Returns:
        format letter for data in column icol, or 0 for a column being skipped

      • getDimensions

        public int[] getDimensions​(int icol)
        Description copied from interface: FitsTableSerializer
        Returns the dimensions of the items which will be output for a given column. This will be null only if that column is not being output. Otherwise it will be a zero-element array for a scalar, 1-element array for a vector, etc.
        Specified by:
        getDimensions in interface FitsTableSerializer
        Parameters:
        icol - column to query
        Returns:
        dimensions array for data in column icol or null for a column being skipped

      • getBadValue

        public java.lang.String getBadValue​(int icol)
        Description copied from interface: FitsTableSerializer
        Returns the bad value (text of the TNULLnn card), if any, used for a given column.
        Specified by:
        getBadValue in interface FitsTableSerializer
        Parameters:
        icol - column to query
        Returns:
        blank value string, or null if there is none or the column is being skipped

      • getHealpixHeaders

        protected CardImage[] getHealpixHeaders​(uk.ac.starlink.table.HealpixTableInfo hpxInfo)
                                 throws uk.ac.starlink.table.TableFormatException
        Returns FITS headers specific for a table containing a HEALPix map. If this method is called the assumption is that the table looks like it should be a HEALPix map of some sort. If there are problems with the metadata that prevent a consistent set of headers from being generated, a TableFormatException with an informative message should be thrown.
        Parameters:
        hpxInfo - non-null healpix description
        Returns:
        array of FITS headers describing healpix information
        Throws:
        uk.ac.starlink.table.TableFormatException