[Maven Integration] Bundle TrainDataLibs as Resources within JAR.

Author: ingo-budde

swan_core/src/main/java/de/fraunhofer/iem/swan/FileUtility.java

@@ -0,0 +1,174 @@
+package de.fraunhofer.iem.swan;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+import org.apache.commons.io.FileUtils;
+
+/**
+ * This class can extract resource entries from the JAR file that this
+ * application is located in. Also it keeps track of extracted files to delete
+ * them when the application is exiting.
+ * 
+ * @author Ingo Budde (Fraunhofer IEM)
+ *
+ */
+public class FileUtility {
+
+	/**
+	 * List of temporary files that have been created and must be deleted before
+	 * exiting the application.
+	 */
+	private List<File> tempFiles = new ArrayList<File>();
+
+	/**
+	 * List of temporary directories that have been created and must be deleted
+	 * before exiting the application.
+	 */
+	private List<File> tempDirs = new ArrayList<File>();
+
+	/**
+	 * Finds and provides the bundled directory with the given resource location
+	 * inside this application's jar file. If it is not directly accessable from the
+	 * filesystem, it is copied to a temporary location.
+	 * 
+	 * @param resourceLocation The location of the directory within the jar file.
+	 * @return The File describing the location of the provided directory.
+	 * @throws IOException When an error occurs while copying the directory.
+	 */
+	public File getResourceDirectory(String resourceLocation) throws IOException {
+
+		File localFile = getLocalResource(resourceLocation);
+		if (localFile != null) {
+			return localFile;
+		}
+
+		// Create Temporary Directory
+		Path path = Files.createTempDirectory("swan");
+		File tempDir = path.toFile();
+		this.tempDirs.add(tempDir);
+
+		// Find JAR Entries
+		URL url = FileUtility.class.getResource(resourceLocation);
+		if (resourceLocation.startsWith("/")) {
+			resourceLocation = resourceLocation.substring(1);
+		}
+		if ("jar".equals(url.getProtocol())) {
+			String[] splitted = url.getPath().split("\\!");
+			splitted = splitted[0].split("file:/");
+			String jarPath = splitted[splitted.length - 1];
+			File jarFile = new File(jarPath);
+			if (jarFile.exists()) {
+				JarFile jar = null;
+				try {
+					jar = new JarFile(jarFile.getAbsolutePath());
+					Enumeration<JarEntry> entries = jar.entries(); // gives ALL entries in jar
+					while (entries.hasMoreElements()) {
+						String name = entries.nextElement().getName();
+						if (name.startsWith(resourceLocation) && !name.endsWith("/")) {
+							String destinationName = name.substring(resourceLocation.length());
+							File destination = new File(tempDir, destinationName);
+							InputStream stream = FileUtility.class.getResourceAsStream("/" + name);
+							FileUtils.copyInputStreamToFile(stream, destination);
+						}
+					}
+				} finally {
+					if (jar != null) {
+						jar.close();
+					}
+				}
+			}
+		}
+		return tempDir;
+	}
+
+	/**
+	 * Finds and provides the bundled file with the given resource location inside
+	 * this application's jar file. If it is not directly accessable from the
+	 * filesystem, it is copied to a temporary location.
+	 * 
+	 * @param resourceLocation The location of the file within the jar file.
+	 * @return The File describing the location of the provided file.
+	 * @throws IOException When an error occurs while copying the file.
+	 */
+	public File getResourceFile(String resourceLocation) throws IOException {
+		return getResourceFile(resourceLocation, null);
+	}
+
+	/**
+	 * Finds and provides the bundled file with the given resource location inside
+	 * this application's jar file. If it is not directly accessable from the
+	 * filesystem, it is copied to a temporary location.
+	 * 
+	 * @param resourceLocation     The location of the file within the jar file.
+	 * @param destinationDirectory The directory to place the file in, in case it
+	 *                             needs to be copied. If <code>null</code>, a new
+	 *                             temporary file is created and used.
+	 * @return The File describing the location of the provided file.
+	 * @throws IOException When an error occurs while copying the file.
+	 */
+	public File getResourceFile(String resourceLocation, File destinationFile) throws IOException {
+		File localFile = getLocalResource(resourceLocation);
+		if (localFile != null) {
+			return localFile;
+		}
+		String[] segments = resourceLocation.split("\\/|\\\\");
+		String filename = segments[segments.length - 1];
+		if (destinationFile == null) {
+			Path path = Files.createTempFile("swan", filename);
+			File tempFile = path.toFile();
+			destinationFile = tempFile;
+			this.tempFiles.add(tempFile);
+		}
+
+		InputStream stream = FileUtility.class.getResourceAsStream(resourceLocation);
+		FileUtils.copyToFile(stream, destinationFile);
+
+		return destinationFile;
+	}
+
+	/**
+	 * Returns the jar resource from the local filesystem, if it exists.
+	 * 
+	 * @param resourceLocation The location of the file within the jar file.
+	 * @return The File from the local filesystem, or <code>null</code>, if no such
+	 *         file exists.
+	 */
+	private File getLocalResource(String resourceLocation) {
+		URL url = FileUtility.class.getResource(resourceLocation);
+		if ("file".equals(url.getProtocol())) {
+			return new File(url.getFile());
+		}
+		return null;
+	}
+
+	/**
+	 * Cleans up this object and deletes all temporary files and directies. This
+	 * should be called before the application exists, or after an analysis is done.
+	 */
+	public void dispose() {
+		for (File directory : tempDirs) {
+			try {
+				FileUtils.deleteDirectory(directory);
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+		}
+		for (File file : tempFiles) {
+			try {
+				file.delete();
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+		}
+	}
+}