org.cdlib.xtf.textEngine

Class IndexUtil

Object

IndexUtil

public class IndexUtil
extends Object

This class provides methods related to, but not always part of, a text index. For instance, there are methods to calculate document keys (as used in an index), or lazy file paths. It also maintains a publicly accessible cache of index info entries read from the index config file(s).

Author:

Martin Haye

Field Summary

Fields

Modifier and Type	Field and Description
private static ConfigCache	configCache
private static SAXParserFactory	saxParserFactory
private static TransformerFactory	transformerFactory

Constructor Summary

Constructors

Constructor and Description
IndexUtil()

Method Summary

Modifier and Type	Method and Description
static void	applyPreFilters(Templates[] prefilterStylesheets, XMLReader reader, InputSource xmlSource, AttribList passThroughAttribs, Result ultimateResult) Apply one or more prefilter stylesheets to an XML input source.
static String	calcDocKey(File xtfHome, File idxConfigFile, String idxName, File srcTextFile) Given an index within a config file and the path to the source XML text of a document, this method infers the correct document key that should be stored in the index.
static String	calcDocKey(File xtfHomeFile, IndexInfo idxInfo, File srcTextFile) Given an index within a config file and the path to the source XML text of a document, this method infers the correct document key that should be stored in the index.
static File	calcLazyPath(File xtfHome, File idxConfigFile, String idxName, File srcTextFile, boolean createDir) Given an index within a config file and the path to the source XML text of a document, this method infers the correct path to the lazy version of that source document.
static File	calcLazyPath(File xtfHome, IndexInfo idxInfo, File srcTextFile, boolean createDir) Given an index within a config file and the path to the source XML text of a document, this method infers the correct path to the lazy version of that source document.
static SAXParser	createSAXParser() Create a SAX parser using the best implementation we can find.
static Transformer	createTransformer() Create a Saxon transformer.
static XMLReader	createXMLReader() Create an XML reader using the best implementation we can find.
static InputStream	filterXMLDocument(InputStream inStream, boolean applyCrimsonWorkaround, boolean removeDoctypeDecl) Applies the standard set of filters for an XML document.
static InputStream	filterXMLDocument(InputStream inStream, SAXParser saxParser, boolean removeDoctypeDecl) Applies the standard set of filters for an XML document.
static IndexInfo	getIndexInfo(File idxConfigFile, String idxName) Given an index configuration file and the name of an index within that file, fetch the configuration info.
private static TransformerFactory	getTransformerFactory() Get a TransformerFactory.

Methods inherited from class Object

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

Field Detail

configCache

private static ConfigCache configCache

saxParserFactory

private static SAXParserFactory saxParserFactory

transformerFactory

private static TransformerFactory transformerFactory

Constructor Detail

IndexUtil

public IndexUtil()

Method Detail

getIndexInfo

public static IndexInfo getIndexInfo(File idxConfigFile,
                                     String idxName)
                              throws Exception

Given an index configuration file and the name of an index within that file, fetch the configuration info. This is a memo function, so any given index name will be cached and thus only loaded once.

Parameters:

idxConfigFile - Index configuration file to read

idxName - Name of the index within that file

Returns:

Information for the specified index.

Throws:

Exception - If there is a problem reading the config file.

calcLazyPath

public static File calcLazyPath(File xtfHome,
                                File idxConfigFile,
                                String idxName,
                                File srcTextFile,
                                boolean createDir)
                         throws IOException

Given an index within a config file and the path to the source XML text of a document, this method infers the correct path to the lazy version of that source document. The lazy version will be somewhere within the index's directory.

Parameters:

idxConfigFile - File to load index configuration from

idxName - Index name within the config

srcTextFile - Source text file of interest

createDir - true to create the directory for the lazy file if it doesn't exist; false to never create the directory.

Returns:

Expected location of the lazy version of the source file

Throws:

IOException

calcLazyPath

public static File calcLazyPath(File xtfHome,
                                IndexInfo idxInfo,
                                File srcTextFile,
                                boolean createDir)
                         throws IOException

Given an index within a config file and the path to the source XML text of a document, this method infers the correct path to the lazy version of that source document. The lazy version will be somewhere within the index's directory.

Parameters:

xtfHome - File at the root of the XTF directory tree

idxInfo - Configuration info for the index in question.

srcTextFile - Source text file of interest

createDir - true to create the directory for the lazy file if it doesn't exist; false to never create the directory.

Returns:

Expected location of the lazy version of the source file

Throws:

IOException

calcDocKey

public static String calcDocKey(File xtfHome,
                                File idxConfigFile,
                                String idxName,
                                File srcTextFile)
                         throws IOException

Given an index within a config file and the path to the source XML text of a document, this method infers the correct document key that should be stored in the index.

Parameters:

idxConfigFile - File to load index configuration from

idxName - Index name within the config

srcTextFile - Source text file of interest

Returns:

Document key to store or look for in the index

Throws:

IOException

calcDocKey

public static String calcDocKey(File xtfHomeFile,
                                IndexInfo idxInfo,
                                File srcTextFile)
                         throws IOException

Given an index within a config file and the path to the source XML text of a document, this method infers the correct document key that should be stored in the index.

Parameters:

xtfHomeFile - The XTF_HOME directory

idxInfo - Configuration info for the index in question.

srcTextFile - Source text file of interest

Returns:

Document key to store or look for in the index

Throws:

IOException

createSAXParser

public static SAXParser createSAXParser()

Create a SAX parser using the best implementation we can find. We prefer the new parser supplied by Java 1.5. Failing that, we try for the Crimson parser, and if that's not found, we try the default.

createXMLReader

public static XMLReader createXMLReader()

Create an XML reader using the best implementation we can find. We prefer the new parser supplied by Java 1.5. Failing that, we try for the Crimson parser, and if that's not found, we try the default.

getTransformerFactory

private static TransformerFactory getTransformerFactory()

Get a TransformerFactory.

createTransformer

public static Transformer createTransformer()

Create a Saxon transformer.

filterXMLDocument

public static InputStream filterXMLDocument(InputStream inStream,
                                            boolean applyCrimsonWorkaround,
                                            boolean removeDoctypeDecl)

Applies the standard set of filters for an XML document. In our case, this involves removing document type declarations, and working around a bug in the Apache Crimson parser.

Parameters:

inStream - Document stream to filter

applyCrimsonWorkaround - true to apply the workaround for the 8193-byte bug in the Crimson XML parser.

removeDoctypeDecl - true to remove DOCTYPE declaration; false to leave them alone.

Returns:

Filtered input stream

filterXMLDocument

public static InputStream filterXMLDocument(InputStream inStream,
                                            SAXParser saxParser,
                                            boolean removeDoctypeDecl)

Applies the standard set of filters for an XML document. In our case, this involves removing document type declarations, and working around a bug in the Apache Crimson parser.

Parameters:

inStream - Document stream to filter

saxParser - Parser that will be used to parse the document; used to determine whether or not to apply the Crimson parser workaround.

removeDoctypeDecl - true to remove DOCTYPE declaration; false to leave them alone.

Returns:

Filtered input stream

applyPreFilters

public static void applyPreFilters(Templates[] prefilterStylesheets,
                                   XMLReader reader,
                                   InputSource xmlSource,
                                   AttribList passThroughAttribs,
                                   Result ultimateResult)
                            throws SAXException,
                                   TransformerException,
                                   TransformerConfigurationException

Apply one or more prefilter stylesheets to an XML input source. Pass the filtered data to to the specified Result.

Parameters:

prefilterStylesheets - Stylesheets to process

reader - Reader to use for parsing the input XML

xmlSource - Source of XML data

ultimateResult - Where to send the output

Throws:

SAXException

TransformerException

TransformerConfigurationException