Package uk.ac.starlink.votable

Class FitsPlusTableBuilder

  • All Implemented Interfaces:
    uk.ac.starlink.table.MultiTableBuilder, uk.ac.starlink.table.TableBuilder
    public class FitsPlusTableBuilder
extends java.lang.Object
implements uk.ac.starlink.table.TableBuilder, uk.ac.starlink.table.MultiTableBuilder
    Table builder which can read files in 'fits-plus' format (as written by FitsPlusTableWriter). This looks for a primary header in the FITS file which contains the VOTMETA header (in fact it is quite inflexible about what it recognises as this format - see isMagic(byte[])) and tries to interpret the data array as a 1-d array of bytes representing the XML of a VOTable document. This VOTable document should have one or more TABLE elements with no DATA content - the table data is got from the extension extension HDUs, one per table, and they must be BINTABLE extensions matching the metadata described by the VOTable.

    The point of all this is so that you can store VOTables in the efficient FITS format (it can be mapped if it's on local disk, which makes table creation practically instantaneous, even for random access) without sacrificing any of the metadata that you want to encode in VOTable format.

    Since:
    27 Aug 2004
    Author:
    Mark Taylor (Starlink)
    See Also:
    FitsPlusTableWriter

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean canImport​(java.awt.datatransfer.DataFlavor flavor)
      Returns true for a flavor with the MIME type "application/fits".
      java.lang.String getFormatName()  
      static boolean isMagic​(byte[] buffer)
      Tests whether a given buffer contains bytes which might be the first few bytes of a FitsPlus table.
      boolean looksLikeFile​(java.lang.String location)  
      uk.ac.starlink.table.StarTable makeStarTable​(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, uk.ac.starlink.table.StoragePolicy storagePolicy)  
      uk.ac.starlink.table.TableSequence makeStarTables​(uk.ac.starlink.util.DataSource datsrc, uk.ac.starlink.table.StoragePolicy storagePolicy)  
      void streamStarTable​(java.io.InputStream in, uk.ac.starlink.table.TableSink sink, java.lang.String pos)  

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • FitsPlusTableBuilder

        public FitsPlusTableBuilder()
        Default constructor.

      • FitsPlusTableBuilder

        public FitsPlusTableBuilder​(uk.ac.starlink.fits.WideFits wide)
        Constructor.
        Parameters:
        wide - convention for representing extended columns; use null to avoid use of extended columns

    • Method Detail

      • getFormatName

        public java.lang.String getFormatName()
        Specified by:
        getFormatName in interface uk.ac.starlink.table.TableBuilder

      • looksLikeFile

        public boolean looksLikeFile​(java.lang.String location)
        Specified by:
        looksLikeFile in interface uk.ac.starlink.table.TableBuilder

      • makeStarTable

        public uk.ac.starlink.table.StarTable makeStarTable​(uk.ac.starlink.util.DataSource datsrc,
                                                    boolean wantRandom,
                                                    uk.ac.starlink.table.StoragePolicy storagePolicy)
                                             throws java.io.IOException
        Specified by:
        makeStarTable in interface uk.ac.starlink.table.TableBuilder
        Throws:
        java.io.IOException

      • makeStarTables

        public uk.ac.starlink.table.TableSequence makeStarTables​(uk.ac.starlink.util.DataSource datsrc,
                                                         uk.ac.starlink.table.StoragePolicy storagePolicy)
                                                  throws java.io.IOException
        Specified by:
        makeStarTables in interface uk.ac.starlink.table.MultiTableBuilder
        Throws:
        java.io.IOException

      • streamStarTable

        public void streamStarTable​(java.io.InputStream in,
                            uk.ac.starlink.table.TableSink sink,
                            java.lang.String pos)
                     throws java.io.IOException
        Specified by:
        streamStarTable in interface uk.ac.starlink.table.TableBuilder
        Throws:
        java.io.IOException

      • canImport

        public boolean canImport​(java.awt.datatransfer.DataFlavor flavor)
        Returns true for a flavor with the MIME type "application/fits".
        Specified by:
        canImport in interface uk.ac.starlink.table.TableBuilder

      • isMagic

        public static boolean isMagic​(byte[] buffer)
        Tests whether a given buffer contains bytes which might be the first few bytes of a FitsPlus table. The criterion is that it looks like the start of a FITS header, and the first few cards look roughly like this: 
             SIMPLE  =              T
     BITPIX  =              8
     NAXIS   =              1
     NAXIS1  =            ???
     VOTMETA =              T
        Parameters:
        buffer - byte buffer containing leading few bytes of data
        Returns:
        true if it looks like a FitsPlus file