uk.ac.starlink.cdf
Class CdfTableBuilder

java.lang.Object
  extended by uk.ac.starlink.cdf.CdfTableBuilder
All Implemented Interfaces:
TableBuilder

public class CdfTableBuilder
extends java.lang.Object
implements TableBuilder

Table input handler for NASA CDF (Common Data Format) files.

Since:
24 Jun 2013

Field Summary
static CdfTableProfile DEFAULT_PROFILE
          Default CDF-StarTable translation profile.
 
Constructor Summary
CdfTableBuilder()
          Constructs a default Cdf table builder.
CdfTableBuilder(CdfTableProfile profile)
          Constructs a Cdf table builder with a custom translation profile.
 
Method Summary
 boolean canImport(java.awt.datatransfer.DataFlavor flavor)
          Returns false.
static CdfTableProfile createProfile(boolean invarParams, java.lang.String[] descripAttNames, java.lang.String[] unitAttNames, java.lang.String[] blankvalAttNames)
          Constructs an instance of CdfTableProfile with some suggestions for attribute names with known semantics.
 java.lang.String getFormatName()
          Returns "CDF".
 StarTable makeStarTable(DataSource datsrc, boolean wantRandom, StoragePolicy storagePolicy)
          Constructs a StarTable based on a given DataSource.
 void streamStarTable(java.io.InputStream in, TableSink sink, java.lang.String pos)
          Throws a TableFormatException.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEFAULT_PROFILE

public static final CdfTableProfile DEFAULT_PROFILE
Default CDF-StarTable translation profile.

Constructor Detail

CdfTableBuilder

public CdfTableBuilder()
Constructs a default Cdf table builder.


CdfTableBuilder

public CdfTableBuilder(CdfTableProfile profile)
Constructs a Cdf table builder with a custom translation profile.

Parameters:
profile - CDF-Startable translation profile
Method Detail

getFormatName

public java.lang.String getFormatName()
Returns "CDF".

Specified by:
getFormatName in interface TableBuilder
Returns:
one-word description of this handler's format

makeStarTable

public StarTable makeStarTable(DataSource datsrc,
                               boolean wantRandom,
                               StoragePolicy storagePolicy)
                        throws java.io.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
storagePolicy - 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
java.io.IOException - if an unexpected I/O error occurs during processing

canImport

public boolean canImport(java.awt.datatransfer.DataFlavor flavor)
Returns false. I don't think there is a MIME type associated with the CDF format. References to application/x-cdf and application/cdf appear on the web, but neither is IANA registered, and I think they refer to some other format.

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

streamStarTable

public void streamStarTable(java.io.InputStream in,
                            TableSink sink,
                            java.lang.String pos)
                     throws java.io.IOException
Throws a TableFormatException. CDF is not suitable for streaming.

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
java.io.IOException - if some other error occurs

createProfile

public static CdfTableProfile createProfile(boolean invarParams,
                                            java.lang.String[] descripAttNames,
                                            java.lang.String[] unitAttNames,
                                            java.lang.String[] blankvalAttNames)
Constructs an instance of CdfTableProfile with some suggestions for attribute names with known semantics.

Parameters:
invarParams - true for turning non-row-varying variables into table parameters, false for turning them into variables
descripAttNames - ordered list of names of attributes that might supply description metadata
unitAttNames - ordered list of names of attributes that might supply units metadata
blankvalAttNames - ordered list of names of attributes that might supply magic blank values
Returns:
new profile instance