Class AbstractFitsTableWriter

  • All Implemented Interfaces:
    uk.ac.starlink.table.MultiStarTableWriter, uk.ac.starlink.table.StarTableWriter
    Direct Known Subclasses:
    ColFitsTableWriter, FitsTableWriter, HduFitsTableWriter, HealpixFitsTableWriter, VariableFitsTableWriter

    public abstract class AbstractFitsTableWriter
    extends uk.ac.starlink.table.StreamStarTableWriter
    implements uk.ac.starlink.table.MultiStarTableWriter
    Abstract table writer superclass designed for writing FITS tables.

    A couple of Auxiliary metadata items of the ColumnInfo metadata from written tables are respected:

    • Tables.NULL_VALUE_INFO: sets the value of TNULLn "magic" blank value for integer columns
    • Tables.UBYTE_FLAG_INFO: if set to Boolean.TRUE and if the column has content class Short or short[], the data will be written as unsigned bytes (TFORMn='B') not 16-bit signed integers (TFORMn='I').
    • BintableStarTable.LONGOFF_INFO: if this is set to a string representation of an integer value, and the column has content class String or String[], then the data will be written as long integers (TFORMn='K') with the given offset (TZEROn=...). This option supports round-tripping of offset long values (typically representing unsigned longs) which are converted to strings on read.
    Since:
    27 Jun 2006
    Author:
    Mark Taylor
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected AbstractFitsTableWriter​(java.lang.String formatName)
      Constructor.
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      protected abstract FitsTableSerializer createSerializer​(uk.ac.starlink.table.StarTable table)
      Provides a suitable serializer for a given table.
      boolean getAllowSignedByte()
      Returns a flag indicating how Byte-valued columns are written.
      boolean getAllowZeroLengthString()
      Indicates whether zero-length string columns may be output.
      FitsTableSerializerConfig getConfig()
      Returns the configuration details for writing FITS files.
      static java.lang.String getCurrentDate()
      Returns an ISO-8601 data string representing the time at which this method is called.
      java.lang.String getFormatName()  
      protected java.util.List<CardImage> getMetadataCards()
      Adds some standard metadata header cards to a FITS table header.
      java.lang.String getMimeType()
      Returns "application/fits".
      byte getPadCharacter()
      Returns the byte value with which under-length string (character array) values will be padded.
      WideFits getWide()
      Indicates the convention in use for representing over-wide tables.
      boolean getWriteDate()
      Indicates whether a datestamp is written to output FITS files.
      void setAllowSignedByte​(boolean allowSignedByte)
      Configures how Byte-valued columns are written.
      void setAllowZeroLengthString​(boolean allowZeroLengthString)
      Sets whether zero-length string columns may be written.
      void setFormatName​(java.lang.String formatName)
      Sets the declared format name.
      void setPadCharacter​(byte padChar)
      Sets the byte value with which under-length string (character array) values should be padded.
      void setWide​(WideFits wide)
      Sets the convention for representing over-wide (>999 column) tables.
      void setWriteDate​(boolean writeDate)
      Configures whether a datestamp is written to output FITS files.
      void writePrimaryHDU​(java.io.OutputStream out)
      Writes the primary HDU.
      void writeStarTable​(uk.ac.starlink.table.StarTable table, java.io.OutputStream out)
      Writes a single table.
      void writeStarTables​(uk.ac.starlink.table.TableSequence tableSeq, java.io.OutputStream out)
      Writes tables.
      void writeStarTables​(uk.ac.starlink.table.TableSequence tableSeq, java.lang.String location, uk.ac.starlink.table.StarTableOutput sto)
      void writeTableHDU​(uk.ac.starlink.table.StarTable table, FitsTableSerializer fitser, java.io.OutputStream out)
      Writes a data HDU.
      • Methods inherited from class uk.ac.starlink.table.StreamStarTableWriter

        writeStarTable, writeStarTable
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
      • Methods inherited from interface uk.ac.starlink.table.StarTableWriter

        looksLikeFile, writeStarTable
    • Constructor Detail

      • AbstractFitsTableWriter

        protected AbstractFitsTableWriter​(java.lang.String formatName)
        Constructor.
        Parameters:
        formatName - format name
    • Method Detail

      • getFormatName

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

        public void setFormatName​(java.lang.String formatName)
        Sets the declared format name.
        Parameters:
        formatName - format name
      • getMimeType

        public java.lang.String getMimeType()
        Returns "application/fits".
        Specified by:
        getMimeType in interface uk.ac.starlink.table.StarTableWriter
        Returns:
        MIME type
      • writeStarTables

        public void writeStarTables​(uk.ac.starlink.table.TableSequence tableSeq,
                                    java.io.OutputStream out)
                             throws java.io.IOException
        Writes tables. Calls writePrimaryHDU(java.io.OutputStream) to write the primary HDU. Subclasses which want to put something related to the input tables into the primary HDU will need to override this method (writeStarTables).
        Specified by:
        writeStarTables in interface uk.ac.starlink.table.MultiStarTableWriter
        Throws:
        java.io.IOException
      • writeStarTables

        public void writeStarTables​(uk.ac.starlink.table.TableSequence tableSeq,
                                    java.lang.String location,
                                    uk.ac.starlink.table.StarTableOutput sto)
                             throws java.io.IOException
        Specified by:
        writeStarTables in interface uk.ac.starlink.table.MultiStarTableWriter
        Throws:
        java.io.IOException
      • writePrimaryHDU

        public void writePrimaryHDU​(java.io.OutputStream out)
                             throws java.io.IOException
        Writes the primary HDU. This cannot contain a table since BINTABLE HDUs can only be extensions. The AbstractFitsTableWriter implementation writes a minimal, data-less HDU.
        Parameters:
        out - destination stream
        Throws:
        java.io.IOException
      • writeTableHDU

        public void writeTableHDU​(uk.ac.starlink.table.StarTable table,
                                  FitsTableSerializer fitser,
                                  java.io.OutputStream out)
                           throws java.io.IOException
        Writes a data HDU.
        Parameters:
        table - the table to be written into the HDU
        fitser - fits serializer initalised from table
        out - destination stream
        Throws:
        java.io.IOException
      • getConfig

        public FitsTableSerializerConfig getConfig()
        Returns the configuration details for writing FITS files. Its content can be controlled using single-config-item mutator methods (which may also be labelled as ConfigMethods) on this class. This covers things that are generally orthogonal to the type of serialization, so may be set for any kind of FITS output, which is why it makes sense to manage them in the AbstractFitsTableWriter abstract superclass.
        Returns:
        object representing the FITS serialization options currently configured for this writer
      • createSerializer

        protected abstract FitsTableSerializer createSerializer​(uk.ac.starlink.table.StarTable table)
                                                         throws java.io.IOException
        Provides a suitable serializer for a given table. Note this should throw an IOException if it can be determined that the submitted table cannot be written by this writer, for instance if it has too many columns.
        Parameters:
        table - table to serialize
        Returns:
        FITS serializer
        Throws:
        java.io.IOException - if the table can't be written
      • getMetadataCards

        protected java.util.List<CardImage> getMetadataCards()
        Adds some standard metadata header cards to a FITS table header. This includes date stamp, STIL version, etc.
        Returns:
        list of cards giving write-specific metadata
      • setWriteDate

        @ConfigMethod(property="date",
                      doc="<p>If true, the DATE-HDU header is filled in with the current date; otherwise it is not included.</p>")
        public void setWriteDate​(boolean writeDate)
        Configures whether a datestamp is written to output FITS files.
        Parameters:
        writeDate - true to include DATE-HDU, false to omit it
      • getWriteDate

        public boolean getWriteDate()
        Indicates whether a datestamp is written to output FITS files.
        Returns:
        true to include DATE-HDU, false to omit it
      • setAllowSignedByte

        public void setAllowSignedByte​(boolean allowSignedByte)
        Configures how Byte-valued columns are written. This is a bit fiddly, since java bytes are signed, but FITS 8-bit integers are unsigned. If true, they are written as FITS unsigned 8-bit integers with an offset, as discussed in the FITS standard (TFORMn='B', TZERO=-128). If false, they are written as FITS signed 16-bit integers.
        Parameters:
        allowSignedByte - true to write offset bytes, false to write shorts
      • getAllowSignedByte

        public boolean getAllowSignedByte()
        Returns a flag indicating how Byte-valued columns are written.
        Returns:
        true to write offset bytes, false to write shorts
      • setAllowZeroLengthString

        public void setAllowZeroLengthString​(boolean allowZeroLengthString)
        Sets whether zero-length string columns may be written. Such columns (TFORMn='0A') are explicitly permitted by the FITS standard, but they can cause crashes because of divide-by-zero errors when encountered by some versions of CFITSIO (v3.50 and earlier), so FITS writing code may wish to avoid them. If this is set false, then A repeat values will always be >=1.
        Parameters:
        allowZeroLengthString - false to prevent zero-length string columns
      • getAllowZeroLengthString

        public boolean getAllowZeroLengthString()
        Indicates whether zero-length string columns may be output.
        Returns:
        false if zero-length string columns are avoided
      • setWide

        public void setWide​(WideFits wide)
        Sets the convention for representing over-wide (>999 column) tables.
        Parameters:
        wide - wide-table representation policy, null to avoid wide tables
      • getWide

        public WideFits getWide()
        Indicates the convention in use for representing over-wide tables.
        Returns:
        wide-table representation policy, null for no wide tables
      • setPadCharacter

        public void setPadCharacter​(byte padChar)
        Sets the byte value with which under-length string (character array) values should be padded. This should normally be one of 0x00 (ASCII NUL) or 0x20 (space). The function of an ASCII NUL is to terminate the string early, as described in Section 7.3.3.1 of the FITS 4.0 standard; space characters pad it to its declared length with whitespace. Other values in the range 0x21-0x7E are permitted but probably not sensible.
        Parameters:
        padChar - character data padding byte
      • getPadCharacter

        public byte getPadCharacter()
        Returns the byte value with which under-length string (character array) values will be padded. This will normally be one of 0x00 (ASCII NUL) or 0x20 (space).
        Returns:
        character data padding byte
      • getCurrentDate

        public static java.lang.String getCurrentDate()
        Returns an ISO-8601 data string representing the time at which this method is called.
        Returns:
        date string