eu.scape_project.tool.toolwrapper.data.components_spec.utils.Utils.java Source code

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Here is the source code for eu.scape_project.tool.toolwrapper.data.components_spec.utils.Utils.java

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/**
 ################################################################################
 #                  Copyright 2012 The SCAPE Project Consortium
 #
 #   This software is copyrighted by the SCAPE Project Consortium. 
 #   The SCAPE project is co-funded by the European Union under
 #   FP7 ICT-2009.4.1 (Grant Agreement number 270137).
 #
 #   Licensed 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 eu.scape_project.tool.toolwrapper.data.components_spec.utils;

import eu.scape_project.tool.toolwrapper.data.components_spec.Components;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.xml.XMLConstants;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;

import org.apache.commons.io.FileUtils;
import org.apache.log4j.Logger;
import org.xml.sax.SAXException;

/**
 * Utility class with static methods useful to interact with component spec info
 * */

public final class Utils {
    private static Logger log = Logger.getLogger(Utils.class);
    private static final String COMPONENTS_SPEC_FILENAME_IN_RESOURCES = "/component-1.1_draft.xsd";

    private Utils() {
    }

    /**
     * Method that creates a {@link Components} instance from the provided
     * component spec file, validating it against component spec XML Schema
     * 
     * @param componentSpecFilePath
     *            path to the component spec file
     */
    public static Components createComponents(String componentSpecFilePath) {
        Components component = null;
        File schemaFile = null;
        try {
            JAXBContext context = JAXBContext.newInstance(Components.class);
            Unmarshaller unmarshaller = context.createUnmarshaller();

            // copy XML Schema from resources to a temporary location
            schemaFile = File.createTempFile("schema", null);
            FileUtils.copyInputStreamToFile(Utils.class.getResourceAsStream(COMPONENTS_SPEC_FILENAME_IN_RESOURCES),
                    schemaFile);
            Schema schema = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(schemaFile);

            // validate provided toolspec against XML Schema
            unmarshaller.setSchema(schema);

            // unmarshal it
            final FileInputStream stream = new FileInputStream(new File(componentSpecFilePath));
            try {
                component = unmarshaller.unmarshal(new StreamSource(stream), Components.class).getValue();
            } finally {
                stream.close();
            }
        } catch (JAXBException e) {
            log.error("The component spec provided doesn't validate against its schema!", e);
        } catch (SAXException e) {
            log.error("The XML Schema is not valid!", e);
        } catch (IOException e) {
            log.error("An error occured while copying the XML Schema from the resources to a temporary location!",
                    e);
        } catch (Exception e) {
            log.error("An error occured!", e);
        } finally {
            if (schemaFile != null) {
                schemaFile.deleteOnExit();
            }
        }
        return component;
    }
}