001/** 
002 * Copyright (c) 2011, Regents of the University of Colorado 
003 * All rights reserved.
004 * 
005 * Redistribution and use in source and binary forms, with or without
006 * modification, are permitted provided that the following conditions are met:
007 * 
008 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 
009 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 
010 * Neither the name of the University of Colorado at Boulder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 
011 * 
012 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
013 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
014 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
015 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
016 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
017 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
018 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
019 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
020 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
021 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
022 * POSSIBILITY OF SUCH DAMAGE. 
023 */
024package org.cleartk.util;
025
026import java.io.BufferedInputStream;
027import java.io.FileInputStream;
028import java.io.FileNotFoundException;
029import java.io.IOException;
030import java.io.InputStream;
031import java.net.MalformedURLException;
032import java.net.URL;
033
034/**
035 * <br>
036 * Copyright (c) 2011, Regents of the University of Colorado <br>
037 * All rights reserved.
038 * 
039 * @author Philip Ogren
040 */
041
042public class IoUtil {
043
044  /**
045   * This method attempts to create an input stream from the given path by:
046   * <ol>
047   * <li>Trying to parse it as a URL</li>
048   * <li>Trying to find it on the classpath, relative to the given class</li>
049   * <li>Trying to find it as a file on the file system</li>
050   * </ol>
051   * 
052   * @param cls
053   *          this will generally be the class of the caller.
054   * @param path
055   *          should be the path of a resource on the classpath (e.g. "/models/en-sent.bin") or the
056   *          path of a file on the local file system (e.g. "src/main/resources/models/en-sent.bin")
057   * @return A newly opened InputStream. The caller is responsible for closing the stream.
058   * @throws IOException
059   *           if the path was not found as a URL, resource or file.
060   */
061  public static InputStream getInputStream(Class<?> cls, String path) throws IOException {
062    InputStream inputStream;
063    try {
064      inputStream = new URL(path).openStream();
065    } catch (MalformedURLException e) {
066      inputStream = cls.getResourceAsStream(path);
067      if (inputStream == null) {
068        try {
069          inputStream = new FileInputStream(path);
070        } catch (FileNotFoundException e1) {
071          throw new IOException(String.format("unable to find %s "
072              + "as a resource on the classpath, as a url or as a file.", path));
073        }
074      }
075    }
076    return new BufferedInputStream(inputStream);
077  }
078}