dbxml.sax
Class JDBCSAXParser

java.lang.Object
  |
  +--dbxml.sax.ParserBase
        |
        +--dbxml.sax.JDBCSAXParser

public class JDBCSAXParser

extends ParserBase

SAX parser that uses a JDBC data source a input instead of an XML file of byte stream. This is a proof-of-concept implemention and does not address all the issues. Many improvements to this parser are possible. This parser treats a table in a database as a virtual XML document.

Author:

Ramnivas Laddad

Fields inherited from class dbxml.sax.ParserBase

_documentHandler, _dtdHandler, _entityResolver, _errorHandler

Constructor Summary

JDBCSAXParser()

Method Summary

protected void	generateSAXEventForColumn(java.sql.ResultSetMetaData rsmd, java.sql.ResultSet rs, int columnIndex) Generate SAX event when visting a column.
protected java.lang.String	getColumnMarker(java.lang.String columnName) Get the marker for indicating the start and end of a column.
protected java.lang.String	getRowMarker() Get the marker for indicating the start and end of a row.
protected java.lang.String	getSelectorSQLStatement(java.lang.String tableName) Get the select query that will be used to obtain the result set for parsing.
protected java.lang.String	getTableMarker(java.lang.String tableName) Get the marker for indicating the start and end of the document.
void	parse(org.xml.sax.InputSource source) Implement the method from base interface.
void	parse(JDBCInputSource source) Parse the given JDBC source to generate SAX events.
void	parse(java.sql.ResultSet rs, java.lang.String tableName) Parse the given JDBC result set object to generate SAX events.
void	parse(java.lang.String systemId) Implement the method from base interface.
void	parse(java.lang.String connectionURL, java.lang.String userName, java.lang.String passwd, java.lang.String tableName) A convenience method that creates a JDBCInputSource object from its argument and parses it

Methods inherited from class dbxml.sax.ParserBase

setDocumentHandler, setDTDHandler, setEntityResolver, setErrorHandler, setLocale

Methods inherited from class java.lang.Object

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

Constructor Detail

JDBCSAXParser

public JDBCSAXParser()

Method Detail

parse

public void parse(org.xml.sax.InputSource source)
           throws org.xml.sax.SAXException,
                  java.io.IOException

Implement the method from base interface. If the argument input source is of type other than JDBCInputSource, it throws an SAXException as this parser cannot deal with it

Parameters:

source - an input source (must be of type JDBCInputSource)

Throws:

org.xml.sax.SAXException - if an error occurs or the argument is not of type JDBCInputSource

java.io.IOException - if an error occurs

parse

public void parse(java.lang.String systemId)
           throws org.xml.sax.SAXException,
                  java.io.IOException

Implement the method from base interface. Always thows an SAXException as the information passed is not sufficient to carry out parsing.

Parameters:

systemId - unused

Throws:

org.xml.sax.SAXException - thrown always

java.io.IOException - never thrown

parse

public void parse(JDBCInputSource source)
           throws org.xml.sax.SAXException,
                  java.io.IOException

Parse the given JDBC source to generate SAX events. Obtains a result set by executing a query returned by getSelectorSQLStatement and then parses that result set.

Parameters:

source - a input source describing database table to be parsed

Throws:

org.xml.sax.SAXException - if an error occurs

java.io.IOException - if an error occurs

parse

public void parse(java.sql.ResultSet rs,
                  java.lang.String tableName)
           throws org.xml.sax.SAXException,
                  java.sql.SQLException,
                  java.io.IOException

Parse the given JDBC result set object to generate SAX events.

Parameters:

rs - result set object to be parsed

tableName - the name of table name being parsed

Throws:

org.xml.sax.SAXException - if an parsing error occurs

java.sql.SQLException - if an SQL error occurs

java.io.IOException - if an i/o error occurs

parse

public void parse(java.lang.String connectionURL,
                  java.lang.String userName,
                  java.lang.String passwd,
                  java.lang.String tableName)
           throws org.xml.sax.SAXException,
                  java.io.IOException

A convenience method that creates a JDBCInputSource object from its argument and parses it

Parameters:

connectionURL - a JDBC URL for the database

userName - user name to connect to the database

passwd - password to connect to the database

tableName - the name of table name being parsed

Throws:

org.xml.sax.SAXException - if an parsing error occurs

java.io.IOException - if an i/o error occurs

generateSAXEventForColumn

protected void generateSAXEventForColumn(java.sql.ResultSetMetaData rsmd,
                                         java.sql.ResultSet rs,
                                         int columnIndex)
                                  throws org.xml.sax.SAXException,
                                         java.sql.SQLException

Generate SAX event when visting a column. Fires startElement event followed by a characters event followed by endElement event. No events are fired for a null data.
This method may be overriden to customize event generation for columns. For example, if one wishes to use special attribute, instead of no events, for indicating null column, then this is the method to override. Also for handling binary data or using desired format for special types such as date and currency, one may override this method.

Parameters:

rsmd - meta data for the result set

rs - the result set

columnIndex - index of column being visited (1 for first column)

Throws:

org.xml.sax.SAXException - if an parsing error occurs

java.sql.SQLException - if an SQL error occurs

getTableMarker

protected java.lang.String getTableMarker(java.lang.String tableName)

Get the marker for indicating the start and end of the document. By default, it is same as the name of the table. Override this to use custom marker.

Parameters:

tableName - the name of table name being parsed

Returns:

the marker desired

getRowMarker

protected java.lang.String getRowMarker()

Get the marker for indicating the start and end of a row. By default it is "row". Override this to use custome marker.

Returns:

the marker desired

getColumnMarker

protected java.lang.String getColumnMarker(java.lang.String columnName)

Get the marker for indicating the start and end of a column. By default it is same as the name of column. Override this to use custome marker.

Parameters:

columnName - a value of type 'String'

Returns:

a value of type 'String'

getSelectorSQLStatement

protected java.lang.String getSelectorSQLStatement(java.lang.String tableName)

Get the select query that will be used to obtain the result set for parsing. By default it is "select * from ". Override this to allow database-level filtering.

Parameters:

tableName - the name of table name being parsed

Returns:

query string