Class CoinsTableBuilder
- All Implemented Interfaces:
TableBuilder
- Since:
- 30 Jun 2010
- Author:
- Mark Taylor
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
canImport
(DataFlavor flavor) Indicates whether this builder is able to turn a resource of media type indicated by flavor into a table.Returns "COINS".boolean
looksLikeFile
(String location) Indicates whether the given location string is of a familiar form for this builder.makeStarTable
(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, StoragePolicy policy) Constructs aStarTable
based on a given DataSource.void
streamStarTable
(InputStream in, TableSink sink, String pos) Reads a table from an input stream and writes it a row at a time to a sink.
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Constructor Details
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CoinsTableBuilder
public CoinsTableBuilder()
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Method Details
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getFormatName
Returns "COINS".- Specified by:
getFormatName
in interfaceTableBuilder
- Returns:
- one-word description of this handler's format
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looksLikeFile
Description copied from interface:TableBuilder
Indicates whether the given location string is of a familiar form for this builder. Implementations should returntrue
if there is a good chance that a file with the givenlocation
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 interfaceTableBuilder
- 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
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canImport
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 itsTableBuilder.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 theDataFlavor
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 interfaceTableBuilder
- 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
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makeStarTable
public StarTable makeStarTable(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, StoragePolicy policy) throws IOException Description copied from interface:TableBuilder
Constructs aStarTable
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 aTableFormatException
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 suppliedstoragePolicy
, or any other resource-expensive measure, to randomise a sequential table just because thewantRandom
parameter is true.- Specified by:
makeStarTable
in interfaceTableBuilder
- Parameters:
datsrc
- the DataSource containing the table resourcewantRandom
- whether, preferentially, a random access table should be returnedpolicy
- a StoragePolicy object which may be used to supply scratch storage if the builder needs it- Returns:
- a StarTable made out of datsrc
- Throws:
IOException
- if an unexpected I/O error occurs during processing
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streamStarTable
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 aTableFormatException
.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 interfaceTableBuilder
- Parameters:
in
- input stream containing table datasink
- destination of the tablepos
- position identifier describing the location of the table within the stream; seeDataSource.getPosition()
(may be null)- Throws:
IOException
- if some other error occurs
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