Class CoinsTableBuilder

java.lang.Object
uk.ac.starlink.table.formats.CoinsTableBuilder
All Implemented Interfaces:
TableBuilder

public class CoinsTableBuilder extends Object implements TableBuilder
Can be used to make sense of the COINS data from the UK Government. It is CSV-like, but has '@' characters as the separators. Tested on file /fact_table_extract_2009_10.zip from http://data.gov.uk/. Clearly, this is of limited use for astronomical analysis, but it may provide a template for implementation of other custom CSV-like data sets.
Since:
30 Jun 2010
Author:
Mark Taylor
  • Constructor Details

    • CoinsTableBuilder

      public CoinsTableBuilder()
  • Method Details

    • getFormatName

      public String getFormatName()
      Returns "COINS".
      Specified by:
      getFormatName in interface TableBuilder
      Returns:
      one-word description of this handler's format
    • looksLikeFile

      public boolean looksLikeFile(String location)
      Description copied from interface: TableBuilder
      Indicates whether the given location string is of a familiar form for this builder. Implementations should return true if there is a good chance that a file with the given location can 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.

      Specified by:
      looksLikeFile in interface TableBuilder
      Parameters:
      location - the location string, such as a filename or URL (not null)
      Returns:
      true iff there is a good chance that the named input can be interpreted by this reader
    • canImport

      public boolean canImport(DataFlavor flavor)
      Description copied from interface: TableBuilder
      Indicates whether this builder is able to turn a resource of media type indicated by flavor into a table. It should return true if it thinks that its 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 DataFlavor flavor. 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 (see StarTableFactory.canImport(java.awt.datatransfer.DataFlavor[])).

      Specified by:
      canImport in interface TableBuilder
      Parameters:
      flavor - the DataFlavor whose suitability as stream input is to be assessed
      Returns:
      true iff this builder reckons it stands a good chance of turning a stream of type flavor into a StarTable
    • makeStarTable

      public StarTable makeStarTable(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, StoragePolicy policy) throws IOException
      Description copied from interface: TableBuilder
      Constructs a StarTable based 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 TableFormatException should 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 wantRandom 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.

      Specified by:
      makeStarTable in interface TableBuilder
      Parameters:
      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
      Returns:
      a StarTable made out of datsrc
      Throws:
      TableFormatException - if the table is not of a kind that can be handled by this handler
      IOException - if an unexpected I/O error occurs during processing
    • streamStarTable

      public void streamStarTable(InputStream in, TableSink sink, String pos) throws IOException
      Description copied from interface: TableBuilder
      Reads a table from an input stream and writes it a row at a time to a sink. Not all implementations will be able to do this; for instance, extracting the table from the data may be a two-pass process. Implementations which are unable to perform this function should throw a 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.

      Specified by:
      streamStarTable in interface TableBuilder
      Parameters:
      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)
      Throws:
      TableFormatException - if the table can't be streamed or the data is malformed
      IOException - if some other error occurs