Class FITSDataNode

java.lang.Object
uk.ac.starlink.datanode.nodes.DefaultDataNode
uk.ac.starlink.datanode.nodes.FITSDataNode
All Implemented Interfaces:
DataNode
Direct Known Subclasses:
FITSFileDataNode, FITSStreamDataNode

public abstract class FITSDataNode extends DefaultDataNode
Abstract DataNode class for representing FITS objects. Subclasses are provided for FITS objects on disk or in a stream.
Author:
Mark Taylor (Starlink)
  • Constructor Details

    • FITSDataNode

      public FITSDataNode(uk.ac.starlink.util.DataSource datsrc) throws NoSuchDataException
      Constructs a FITSDataNode from a data source.
      Parameters:
      datsrc - the source of the data
      Throws:
      NoSuchDataException
  • Method Details

    • getName

      public String getName()
      Description copied from interface: DataNode
      Gets the name of this object. This is an intrinsic property of the object.
      Specified by:
      getName in interface DataNode
      Overrides:
      getName in class DefaultDataNode
      Returns:
      the name of the object
    • getDescription

      public String getDescription()
      Description copied from interface: DataNode
      Gets a concise description of this object. The form of the description will depend on the type of node, but it might detail the shape or type of data represented, or otherwise give some information additional to the name. It should not include the return value of the getName method, since they may be presented together. It should be on one line, and preferably no longer than around 70 characters. The null value may be returned if there is nothing to say.
      Specified by:
      getDescription in interface DataNode
      Overrides:
      getDescription in class DefaultDataNode
      Returns:
      a short string describing this object
    • allowsChildren

      public boolean allowsChildren()
      Description copied from class: DefaultDataNode
      The DefaultDataNode implementation of this method returns false.
      Specified by:
      allowsChildren in interface DataNode
      Overrides:
      allowsChildren in class DefaultDataNode
      Returns:
      true if the node is of a type which can have child nodes, false otherwise
    • getArrayData

      protected abstract FITSDataNode.ArrayDataMaker getArrayData(long start, long size)
      Returns an ArrayDataMaker encapsulating the same input stream as the on one which this FITSDataNode is based, but starting at a given offset start into the stream and size bytes long.
      Parameters:
      start - the offset into this FITSDataNode's stream at which the returned source's streams should start
      size - the number of bytes contained by the returned source's stream
    • getChildIterator

      public Iterator getChildIterator()
      Description copied from class: DefaultDataNode
      The DefaultDataNode implementation of this method throws UnsupportedOperationException (DefaultDataNode.allowsChildren() is false).
      Specified by:
      getChildIterator in interface DataNode
      Overrides:
      getChildIterator in class DefaultDataNode
      Returns:
      an Iterator over the children. Each object iterated over should be a DataNode. Behaviour is undefined if this method is called on an object for which allowsChildren returns false.
    • getPathSeparator

      public String getPathSeparator()
      Description copied from class: DefaultDataNode
      Returns a default separator string.
      Specified by:
      getPathSeparator in interface DataNode
      Overrides:
      getPathSeparator in class DefaultDataNode
      Returns:
      "."
    • getNodeTLA

      public String getNodeTLA()
      Description copied from class: DefaultDataNode
      The DefaultDataNode implementation returns the string "...".
      Specified by:
      getNodeTLA in interface DataNode
      Overrides:
      getNodeTLA in class DefaultDataNode
      Returns:
      "..."
    • getNodeType

      public String getNodeType()
      Description copied from interface: DataNode
      Returns a short sentence indicating what kind of node this is. The return value should be just a few words. As a rough guideline it should indicate what the implementing class is.
      Specified by:
      getNodeType in interface DataNode
      Overrides:
      getNodeType in class DefaultDataNode
      Returns:
      a short description of the type of this DataNode
    • getDataInput

      protected nom.tam.util.ArrayDataInput getDataInput() throws IOException
      Returns an ArrayDataInput object containing the data from this FITS object.
      Throws:
      IOException
    • isMagic

      public static boolean isMagic(byte[] buffer)
      Indicates whether a buffer of bytes looks like the start of a FITS file.
      Parameters:
      buffer - the first few bytes of a potential stream
      Returns:
      true if buffer matches the FITS file magic number