public class ColFitsPlusTableBuilder extends java.lang.Object implements TableBuilder
TableBuilderinterface which reads tables stored in column-oriented FITS binary table format. The table data is stored in a BINTABLE extension which has a single row; each cell in this row contains the data for an entire column of the represented table. The primary HDU contains a byte array giving the table metadata as a VOTable, as for
FitsPlusTableBuilder. If the VOTMETA card in the primary HDU does not have the value T, the VOTable metadata array is ignored.
This rather specialised format may provide good performance for certain operations on very large, especially very wide, tables. Although it is FITS and can therefore be used in principle for data interchange, in practice most non-STIL processors are unlikely to be able to do much useful with it.
|Constructor and Description|
|Modifier and Type||Method and Description|
Indicates whether this builder is able to turn a resource of media type indicated by flavor into a table.
Returns the name of the format which can be read by this handler.
Indicates whether the given location string is of a familiar form for this builder.
Reads a table from an input stream and writes it a row at a time to a sink.
public ColFitsPlusTableBuilder(WideFits wide)
wide- convention for representing extended columns; use null to avoid use of extended columns
public java.lang.String getFormatName()
public boolean looksLikeFile(java.lang.String location)
trueif there is a good chance that a file with the given
locationcan be interpreted by this reader, for instance if it has a suitable file extension.
This method may be used to guess, on a best-efforts basis, whether this builder is suitable for reading a file from a given location. Attempts may still be made to read inputs for which this method returns false. It is less important for builders that can recognise files by magic number, which is generally preferable to using filenames.
location- the location string, such as a filename or URL (not null)
public void streamStarTable(java.io.InputStream in, TableSink sink, java.lang.String pos) throws TableFormatException
The input stream should be prepared for use prior to calling this method, so implementations should not in general attempt to decompress or buffer istrm.
in- input stream containing table data
sink- destination of the table
pos- position identifier describing the location of the table within the stream; see
DataSource.getPosition()(may be null)
TableFormatException- if the table can't be streamed or the data is malformed
public boolean canImport(java.awt.datatransfer.DataFlavor flavor)
TableBuilder.streamStarTable(java.io.InputStream, uk.ac.starlink.table.TableSink, java.lang.String)method stands a reasonable chance of successfully constructing a StarTable from a DataSource whose input stream is described by the
DataFlavorflavor. It will typically make this determination based on the flavor's MIME type.
This method should only return true if the flavor looks like it is targeted at this builder; for instance a builder which uses a text-based format should return false for a flavor which indicates a MIME type of text/plain.
This method is used in supporting drag and drop functionality
flavor- the DataFlavor whose suitability as stream input is to be assessed
public StarTable makeStarTable(DataSource datsrc, boolean wantRandom, StoragePolicy policy) throws java.io.IOException
StarTablebased on a given DataSource. If the source is not recognised or this builder does not know how to construct a table from it, then a
TableFormatExceptionshould be thrown. If this builder thinks it should be able to handle the source but an error occurs during processing, an IOException can be thrown.
The wantRandom parameter is used to indicate whether, ideally, a random-access table should be returned. There is no requirement for the builder to honour this request, but if it knows how to make both random and non-random tables, it can use this flag to decide which to return.
Note: the presence of the
parameter is somewhat misleading. TableBuilder implementations
usually should, and do, ignore it (it would be removed from the
interface if it were not for backward compatibility issues).
Regardless of the value of this parameter, implementations should
return a random-access table only if it is easy for them to do so;
in particular they should not use the supplied
storagePolicy, or any other resource-expensive measure,
to randomise a sequential table just because the
wantRandom parameter is true.
datsrc- the DataSource containing the table resource
wantRandom- whether, preferentially, a random access table should be returned
policy- a StoragePolicy object which may be used to supply scratch storage if the builder needs it
TableFormatException- if the table is not of a kind that can be handled by this handler
java.io.IOException- if an unexpected I/O error occurs during processing
public static boolean isMagic(byte buffer)