/**
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.tuscany.samples.sdo.specCodeSnippets;
import java.io.InputStream;
import org.apache.tuscany.samples.sdo.SdoSampleConstants;
import org.apache.tuscany.sdo.util.SDOUtil;
import commonj.sdo.helper.XMLHelper;
import commonj.sdo.helper.XSDHelper;
import commonj.sdo.DataObject;
import commonj.sdo.DataGraph;
import commonj.sdo.Sequence;
/**
* Demonstrates a vareity of methods available to obtain the root DataObject
* contained within an xml representation of a DataGraph. This is currently a grey
* area of the specification and this samples demonstrates spec complant means, as
* well as utility methods that have been added to Tuscany to address issues within
* the specification.
*
* The following sample is from the <a href="http://incubator.apache.org/tuscany"
* target="_blank"> Apache Tuscany</a> project. It was written to help users
* understand and experiement with SDO. It is based upon example code contained
* within, and is meant for use with, and reference to the <a
* href="http://www.osoa.org/download/attachments/791/SDO_Specification_Java_V2.01.pdf?version=1"
* target="_bank">SDO Specification</a>. This sample addresses confusing aspects of
* the the AccessDataObjectsUsingXPath example from the Examples section of the SDO
* specification.<br>
* <br>
* To define the correct Types for each DataObject ( CompanyType, DepartmentType etc )
* this sample relies upon
* {@link org.apache.tuscany.samples.sdo.SdoSampleConstants#COMPANY_XSD} which is
* provided in the resources directory of these samples. The xml file
* {@link org.apache.tuscany.samples.sdo.SdoSampleConstants#COMPANY_DATAGRAPH_XML} is
* used to load the DataGraph and is also located in this resources directory. <br>
* <br>
* <b>Usage:</b> <br>
* This sample can easily be run from within Eclipse as a Java Application if tuscany or
* the sample-sdo project is imported into Eclipse as an existing project.
* <br><br>
* If executing as a standalone application please do the following:
* <br>
* <UL>
* <LI>Include the following jar files on your classpath :
* <UL>
* <LI>SDO API and Tuscany Implementation
* <UL>
* <LI>sdo-api-{version}.jar - SDO API
* <LI>tuscany-sdo-impl-{version}.jar - Tuscany SDO implementation
* </UL>
* </LI>
* <LI>EMF dependencies.
* <UL>
* <LI>emf-common-{version}.jar - some common framework utility and base classes
* <LI>emf-ecore-{version}.jar - the EMF core runtime implementation classes (the Ecore metamodel)
* <LI>emf-ecore-change-{version}.jar - the EMF change recorder and framework
* <LI>emf-ecore-xmi-{version}.jar - EMF's default XML (and XMI) serializer and loader
* <LI>xsd-{version}.jar - the XML Schema model
* </UL>
* </LI>
* </UL>
*
* These jar files can be obtained from directly from Tuscany and EMF projects or from <a
* href="http://wiki.apache.org/ws-data/attachments/Tuscany(2f)TuscanyJava(2f)SDO_Java_Overview/attachments/SDO%20Execution%20Dependencies"
* target="_bank">SDO Execution Dependancies </a> </LI>
* <LI>Execute: <br>
* java org.apache.tuscany.samples.sdo.specCodeSnippets.ObtainingDataGraphFromXml</LI>
* </UL>
*
* @see org.apache.tuscany.samples.sdo.specExampleSection.AccessDataObjectsUsingXPath
* @author Robbie Minshall
*/
public class ObtainingDataGraphFromXml {
/**
* Execute this method in order to run the sample.
*
* @param args
*/
public static void main(String[] args) {
System.out.println("***************************************");
System.out.println("SDO Sample ObtainingDataGraphFromXml");
System.out.println("***************************************");
System.out.println("Demonstrates a vareity of methods available to obtain the root DataObject"
+ "contained within an xml representation of a DataGraph.");
System.out.println("***************************************");
// define Types
try {
System.out.println("Defining Types using XSD");
InputStream is = null;
is = ClassLoader.getSystemResourceAsStream(SdoSampleConstants.COMPANY_XSD);
XSDHelper.INSTANCE.define(is, null);
is.close();
System.out.println("Type definition completed");
} catch (Exception e) {
System.out.println("Exception caught defining types " + e.toString());
e.printStackTrace();
}
try {
/**
* A DataGraph is an optional envelope for a graph of DataObjects and an
* associated ChangeSummary.
*
* The specification group is currently investigating options regarding
* obtaining a DataGraph from an xml file as well as the role of the
* DataGraph within the SDO specification.
*
* In order to obtain the rootObject contained within the specification
* the specification demonstrates reading in an XML file and obtaining a
* DataObject that represents the datagraph contained within the file.
* Note, that the specification does not obtain a DataGraph - there are
* not mechanisms within the specification for obtaining a DataGraph from
* xml. Obtaining the root DataObject from this datagraph representation
* is quite cumbersome and is demonstrated below.
*
* In order to address this current limitation within the specification
* Tuscany has added a utility method to SDOUtil that allows a user to
* obtain an actual DataGraph from xml.
*/
DataObject company = null;
/**
* Use specification mechanism for obtaining a DataObject that represents
*/
// the a datagraph
System.out.println("Using specification methods to obtain DataObject represeenting a datagraph from xml");
// When the xml file represents a DataGraph the root Object
// of the XMLDocument is a DataGraph
DataObject dataObjectRepresentingDataGraph = XMLHelper.INSTANCE.load(
ClassLoader.getSystemResourceAsStream(SdoSampleConstants.COMPANY_DATAGRAPH_XML)).getRootObject();
// Obtain the company DataObject from the DataObject representing the datagraph
Sequence mySeq = (Sequence) dataObjectRepresentingDataGraph.getSequence("any");
company = (DataObject) mySeq.getValue(0);
System.out.println("Obtained DataObject representing datagraph");
System.out.println(dataObjectRepresentingDataGraph);
System.out.println("Obtained root DataObject from datagraph");
System.out.println(company);
System.out.println();
/**
* Use utility method to obtain an actual DataGraph from the xml
*/
DataGraph datagraph = SDOUtil.loadDataGraph(ClassLoader.getSystemResourceAsStream(SdoSampleConstants.COMPANY_DATAGRAPH_XML), null);
// Obtain the company DataObject from the actual DataGraph
company = datagraph.getRootObject();
System.out.println("Obtained actual DataGraph:");
System.out.println(datagraph);
System.out.println("Obtained root DataObject from DataGraph:");
System.out.println(company);
System.out.println();
} catch (Exception e) {
System.out.println("Sorry there was an error encountered " + e.toString());
e.printStackTrace();
}
System.out.println("GoodBye");
}
}