prajna.io

Class XmlDocReader

java.lang.Object

prajna.io.XmlDocReader

All Implemented Interfaces:

FormatReader<DocData>

public class XmlDocReader
extends java.lang.Object
implements FormatReader<DocData>

Document reader that attempts to transform a structured XML document into a nested group of document objects. This class creates documents whenever an XML element is determined to have multiple complex children, and links them to the parent document as objects of the keys. It uses the element tag names for the document keys.

Author:

Edward Swing

Constructor Summary

Constructors

Constructor and Description
XmlDocReader() Create a new XmlDocReader.
XmlDocReader(java.io.File xmlFile) Create a new XML Document reader for the specified file
XmlDocReader(java.net.URL url) Create a new XML document reader for the specified URL

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canRead() Return if this reader can read.
void	close() close the reader
java.lang.String	getFilters() Get the filters for this reader.
java.lang.String	getSource() Get the source for the reader
boolean	hasMoreData() Return whether this reader has more data to read
protected void	parseDocElem(org.w3c.dom.Element elem, DocData doc) Extensible method which performs any special processing on a particular element and its associated document.
java.util.List<DocData>	readData() Read the data, creating DocData elements.
void	setFilters(java.lang.String filters) Set filters for this reader.
void	setSource(java.lang.String source) Set the soruce for this reader

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XmlDocReader

public XmlDocReader()

Create a new XmlDocReader. The input source must be specified using the setSource() method

XmlDocReader

public XmlDocReader(java.io.File xmlFile)

Create a new XML Document reader for the specified file

Parameters:

xmlFile - the XML file to read

XmlDocReader

public XmlDocReader(java.net.URL url)

Create a new XML document reader for the specified URL

Parameters:

url - the url to read from

Method Detail

canRead

public boolean canRead()

Return if this reader can read.

Specified by:

canRead in interface FormatReader<DocData>

Returns:

true if the reader is in a readable state

close

public void close()

close the reader

Specified by:

close in interface FormatReader<DocData>

getFilters

public java.lang.String getFilters()

Get the filters for this reader.

Specified by:

getFilters in interface FormatReader<DocData>

Returns:

the string representing the filters for this reader

getSource

public java.lang.String getSource()

Get the source for the reader

Specified by:

getSource in interface FormatReader<DocData>

Returns:

a string representation of the input stream

hasMoreData

public boolean hasMoreData()

Return whether this reader has more data to read

Specified by:

hasMoreData in interface FormatReader<DocData>

Returns:

true if the reader has more data to read, false otherwise

parseDocElem

protected void parseDocElem(org.w3c.dom.Element elem,
                DocData doc)

Extensible method which performs any special processing on a particular element and its associated document. This method may be extended by subclasses to handle particular XML formats or schemas. The default implementation does nothing.

Parameters:

elem - the element to parse

doc - the DocData object

readData

public java.util.List<DocData> readData()

Read the data, creating DocData elements. This method reads through the top-level elements, creating DocData objects for each one. It creates sub-documents whenever it finds a complex xml element, and links it to the parent document through the document tags. If a child element is simply a wrapper around a text node, it adds a string tag (or a collection of strings) to the appropriate tag

Specified by:

readData in interface FormatReader<DocData>

Returns:

the list of DocData objects corresponding to the top level elements in the XML file.

setFilters

public void setFilters(java.lang.String filters)

Set filters for this reader. The reader expects to have a filter that defines the top level document element to scan for, in the form docElem=elementTag

Specified by:

setFilters in interface FormatReader<DocData>

Parameters:

filters - the set of filters

setSource

public void setSource(java.lang.String source)

Set the soruce for this reader

Specified by:

setSource in interface FormatReader<DocData>

Parameters:

source - the source. This method attempts to open the source first as a URL, then as a local file. If neither works, it throws an IllegalArgumentException