Package org.nfis.gdas.v091

This programmer's manual introduces the main classes of the GDAS 0.9.1 implementation.

See:
Description

Interface Summary

Class Summary

DataRetrieverInterface	DataRetrieverInterface defines the DataRetrieverInterface.getData(String, String, DatasetConfigType, ArrayList, BigInteger, OutputStream) method which writes the Rowset XML element text described in Section 7.2.4 of the
ConfigProperties	This singleton class is used to load a properties file to configure properties specific to GDAS Version 0.9.1 ('orgNfisGdasV091.properties') including the default driver, and the names of the dataHandlerConfig and getCapabilities documents.
Constants	Strings that are referenced by more than one class are inserted in this file.
DataHandler	DataHandler assembles the return XML for a GDAS 0.9.1 GetData request defined in section 7.2 in the GDAS 0.9.1 specification.
GdasServlet091	This class is responsible for listening for GDAS 0.9.1 requests and replying with the appropriate return XML documents.
JDBCDataRetriever	This DataRetrieverInterface implementation connects to a JDBC resource and runs a query using a JDBC connection.

Exception Summary

ServiceReportException

This class wraps the XmlBeans generated class ServiceExceptionReportDocument.

Package org.nfis.gdas.v091 Description

This programmer's manual introduces the main classes of the GDAS 0.9.1 implementation.

Programmer's Manual

GDAS 0.9.1 is implemented using a java servlet listening for the requests defined in the GDAS Specification Version 0.9.1 (2004-05-04).

GdasServlet091.java

The GDAS Servlet responds to requests defined in the GDAS 0.9.1 specification where the version parameter is '0.9.1'. The servlet determines if the correct parameters have been sent. If the request is 'GetCapabilities' (specification section 7.1), the servlet sends back the reply, otherwise it is a 'GetData' (specification section 7.2) request and the parameters are forwarded to the DataHandler for further processing.

DataHandler.java

Using information in the GetCapabilities.xml and dataHandlerConfig.xml (both configuration files are found in the gdas091/WEB-INF directory), the DataHandler determines if a 'GetData' request can be filled. If so it assembles all the elements of the GetDataResponse (specification section 7.2.4) except the <Rowset> element. DataHandler calls the dataset's DataRetrieverInterface implementation (configured in the dataHandlerConfig.xml) to return the <Rowset> data.

DataRetrieverInterface.java

Data to be returned by GDAS is stored in many different formats. The format data is stored in (Excel spreadsheet, Oracle, MySQL, etc) will determine how it is to be queried. If there is a data set that cannot be queried using the current implementation of this interface, a new class can be created. The data set can be configured to use this new class in the dataHandlerConfig.xml. Instructions for configuring the dataHandlerConfig.xml can be accessed by opening the gdasUserGuide.html in the 'UserGuide' directory of the distribution.

JDBCDataRetriever.java

Implementing the DataRetrieverInterface.java, the JDBCDataRetriever can query any data store there is a JDBC driver for. Each data set using JDBCDataRetriever is configured to use a specific JDBC driver in the dataHandlerConfig.xml see the GDAS User's Guide located in the 'UserGuide' directory of this distribution.