Class SourceReader

java.lang.Object
uk.ac.starlink.util.SourceReader

public class SourceReader extends Object
Convenience class to manipulate XML Sources. Methods are provided to do the useful things you might want done with from a Source. Depending on the type of the input source this may involve an XML transformation or it may not; such a transformation is not performed if it is not required.

The transformer object used in the case that transformations are required may be accessed or set to permit some customisation of the way the transformation is done. Some convenience methods are provided for doing these settings as well.

Author:
Mark Taylor (Starlink)
  • Constructor Details

    • SourceReader

      public SourceReader()
  • Method Details

    • getTransformer

      public Transformer getTransformer()
      Returns a reference to the Transformer object used for transformations used by this object. Its characteristics may be changed if required. Note that in the case a transformation is not required (e.g. in the case of getting a DOM node from a source which is already a DOMSource) this transformer will not be used.
      Returns:
      the transformer object used when transformation is necessary
    • setTransformer

      public void setTransformer(Transformer trans)
      Sets the transformer object used for transformations. Note that in the case a transformation is not required (e.g. in the case of getting a DOM node from a source which is already a DOMSource) this transformer will not be used.
      Parameters:
      trans - the transformer object to be used when transformation is necessary. If null is supplied, a default transformer will be used.
    • getDOM

      public Node getDOM(Source src) throws TransformerException
      Returns a DOM Node representing the given source. Transformation errors are handled by this object's Transformer, whose behaviour is in turn determined by its ErrorListener. By default, this SourceReader is installed as the ErrorListener.
      Parameters:
      src - the Source for which the DOM is required
      Returns:
      a DOM node (typically an Element) representing the XML data in src
      Throws:
      TransformerException - if some error occurs in transformation or I/O
    • getElement

      public Element getElement(Source src) throws TransformerException
      Returns a DOM Element representing the given source. This convenience method invokes getDOM(javax.xml.transform.Source) and then finds an element in the result - if the result is an element that is returned, but if it is a Document then the top-level document element is returned. Anything else throws an IllegalArgumentException.
      Parameters:
      src - the Source for which the DOM is required
      Returns:
      an Element representing the XML data in src
      Throws:
      TransformerException - if some error occurs in transformation or I/O
      IllegalArgumentException - if src does not represent a Document or Element
    • writeSource

      public void writeSource(Source src, Writer wr) throws TransformerException
      Writes the contents of a given Source into a given Writer. Additional buffering will be performed on the writer if necessary. The writer will be flushed, but not closed.

      Hmm, not sure if the encoding is handled correctly here for SAXSources...

      Parameters:
      src - the Source to be written
      wr - the destination for the content of src
      Throws:
      TransformerException - if some error occurs in transformation or I/O
    • writeSource

      public void writeSource(Source src, OutputStream ostrm) throws TransformerException
      Writes the contents of a given Source into a given OutputStream. Additional buffering will be performed on the stream if necessary. The stream will be flushed, but not closed.
      Parameters:
      src - the Source to be written
      ostrm - the destination for the content of src
      Throws:
      TransformerException - if some error occurs in transformation or I/O
    • getXMLStream

      public InputStream getXMLStream(Source src)
      Returns an input stream from which the serialised XML text corresponding to a given Source can be read.
      Parameters:
      src - the Source to be read
      Returns:
      an InputStream which will supply the XML serialisation of src
    • setIndent

      public SourceReader setIndent(int indent)
      Tries to set the indent level used by the writeSource methods. This method modifies the output properties of the the current transformer to affect the way it does the transformation (so will be undone by a subsequent setTransformer). If the supplied indent value is >=0 then the transformer may add whitespace when producing the XML output; it will be encouraged to prettyprint the XML using indent spaces to indicate element nesting, though whether this is actually done depends on which parser is actually being used by JAXP. If indent<0 then no whitespace will be added when outputting XML.

      By default, no whitespace is added.

      For convenience the method returns this SourceReader is returned.

      Parameters:
      indent - indicates if and how whitespace should be added by writeSource methods
      Returns:
      this SourceReader
    • setIncludeDeclaration

      public SourceReader setIncludeDeclaration(boolean flag)
      Sets whether the writeSource methods will output an XML declaration at the start of the XML output. This method modifies the output properties of the the current transformer to affect the way it does the transformation (so will be undone by a subsequent setTransformer).

      By default, the declaration is included

      For convenience the method returns this SourceReader is returned.

      Parameters:
      flag - true if the writeSource methods are to output an XML declaration, false if they are not to
      Returns:
      this SourceReader