taverna-workbench-file-impl/src/main/java/net/sf/taverna/t2/workbench/file/impl/WorkflowBundleOpener.java

/*******************************************************************************
 * Copyright (C) 2007 The University of Manchester
 *
 *  Modifications to the initial code base are copyright of their
 *  respective authors, or their employers as appropriate.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2.1 of
 *  the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 ******************************************************************************/
package net.sf.taverna.t2.workbench.file.impl;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

import net.sf.taverna.t2.workbench.file.AbstractDataflowPersistenceHandler;
import net.sf.taverna.t2.workbench.file.DataflowInfo;
import net.sf.taverna.t2.workbench.file.DataflowPersistenceHandler;
import net.sf.taverna.t2.workbench.file.FileType;
import net.sf.taverna.t2.workbench.file.exceptions.OpenException;

import org.apache.log4j.Logger;

import uk.org.taverna.scufl2.api.container.WorkflowBundle;
import uk.org.taverna.scufl2.api.io.ReaderException;
import uk.org.taverna.scufl2.api.io.WorkflowBundleIO;

public class WorkflowBundleOpener extends AbstractDataflowPersistenceHandler
		implements DataflowPersistenceHandler {
	private static final WorkflowBundleFileType WF_BUNDLE_FILE_TYPE = new WorkflowBundleFileType();
	private static Logger logger = Logger.getLogger(WorkflowBundleOpener.class);
	private WorkflowBundleIO workflowBundleIO;

	@SuppressWarnings("resource")
	@Override
	public DataflowInfo openDataflow(FileType fileType, Object source)
			throws OpenException {
		if (!getOpenFileTypes().contains(fileType))
			throw new OpenException("Unsupported file type " + fileType);
		InputStream inputStream;
		Date lastModified = null;
		Object canonicalSource = source;
		if (source instanceof InputStream) {
			inputStream = (InputStream) source;
		} else if (source instanceof File) {
			try {
				inputStream = new FileInputStream((File) source);
			} catch (FileNotFoundException e) {
				throw new OpenException("Could not open file " + source + ":\n"
						+ e.getLocalizedMessage(), e);
			}
		} else if (source instanceof URL) {
			URL url = ((URL) source);
			try {
				URLConnection connection = url.openConnection();
				connection.setRequestProperty("Accept", "application/zip");
				inputStream = connection.getInputStream();
				if (connection.getLastModified() != 0)
					lastModified = new Date(connection.getLastModified());
			} catch (IOException e) {
				throw new OpenException("Could not open connection to URL "
						+ source + ":\n" + e.getLocalizedMessage(), e);
			}
			try {
				if (url.getProtocol().equalsIgnoreCase("file"))
					canonicalSource = new File(url.toURI());
			} catch (URISyntaxException e) {
				logger.warn("Invalid file URI created from " + url);
			}
		} else
			throw new OpenException("Unsupported source type "
					+ source.getClass());

		final WorkflowBundle workflowBundle;
		try {
			workflowBundle = openDataflowStream(inputStream);
		} finally {
			// We created the stream, we'll close it
			try {
				if (!(source instanceof InputStream))
					inputStream.close();
			} catch (IOException ex) {
				logger.warn("Could not close inputstream " + inputStream, ex);
			}
		}
		if (canonicalSource instanceof File)
			return new FileDataflowInfo(WF_BUNDLE_FILE_TYPE,
					(File) canonicalSource, workflowBundle);
		return new DataflowInfo(WF_BUNDLE_FILE_TYPE, canonicalSource,
				workflowBundle, lastModified);
	}

	protected WorkflowBundle openDataflowStream(InputStream inputStream)
			throws OpenException {
		WorkflowBundle workflowBundle;
		try {
			workflowBundle = workflowBundleIO.readBundle(inputStream, null);
		} catch (ReaderException e) {
			throw new OpenException("Could not read the workflow", e);
		} catch (IOException e) {
			throw new OpenException("Could not open the workflow for parsing",
					e);
		} catch (Exception e) {
			throw new OpenException("Error while opening workflow", e);
		}

		return workflowBundle;
	}

	@Override
	public List<FileType> getOpenFileTypes() {
		return Arrays.<FileType> asList(WF_BUNDLE_FILE_TYPE);
	}

	@Override
	public List<Class<?>> getOpenSourceTypes() {
		return Arrays.<Class<?>> asList(InputStream.class, URL.class,
				File.class);
	}

	public void setWorkflowBundleIO(WorkflowBundleIO workflowBundleIO) {
		this.workflowBundleIO = workflowBundleIO;
	}
}