Java tutorial
/* * org.openmicroscopy.shoola.util.file.IOUtil * *------------------------------------------------------------------------------ * Copyright (C) 2006-2013 University of Dundee. All rights reserved. * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 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 General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * *------------------------------------------------------------------------------ */ package org.openmicroscopy.shoola.util.file; //Java imports import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URL; import java.net.URLClassLoader; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; import java.util.zip.ZipOutputStream; //Third-party libraries import org.apache.commons.io.FilenameUtils; import org.apache.commons.lang.StringUtils; //Application-internal dependencies import org.openmicroscopy.shoola.util.filter.file.ExcelFilter; import org.openmicroscopy.shoola.util.filter.file.PDFFilter; import org.openmicroscopy.shoola.util.filter.file.WordFilter; /** * Collection of static methods to read and write files. * * @author Jean-Marie Burel * <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a> * @author Donald MacDonald * <a href="mailto:donald@lifesci.dundee.ac.uk">donald@lifesci.dundee.ac.uk</a> * @version 3.0 * @since OME3.0 */ public class IOUtil { /** The extension used for the zip.*/ public static final String ZIP_EXTENSION = ".zip"; /** Filter for Microsoft Word documents. */ private static final WordFilter WORD_FILTER; /** Filter for Microsoft Excel documents. */ private static final ExcelFilter EXCEL_FILTER; /** Filter for PDF documents. */ private static final PDFFilter PDF_FILTER; /** The class path.*/ private static String CLASS_PATH_PROPERTY_NAME = "java.class.path"; static { WORD_FILTER = new WordFilter(); PDF_FILTER = new PDFFilter(); EXCEL_FILTER = new ExcelFilter(); } /** * Reads the content of the passed Microsoft Word file. * * @param file The file to handle. * @return See above. */ private static String readWordFile(File file) throws Exception { return null; } /** * Reads the content of the passed Microsoft Excel file. * * @param file The file to handle. * @return See above. */ private static String readExcelFile(File file) throws Exception { return null; } /** * Reads the content of the passed PDF file. * * @param file The file to handle. * @return See above. */ private static String readPDFFile(File file) throws Exception { return null; } /** * Reads the file corresponding to the passed file name. Returns * the input stream or <code>null</code> if the file doesn't exist. * * @param fileName The name of the file to read. * @return See above. * @throws IOException If we cannot read the file or create a stream. */ public static InputStream readFileAsInputStream(String fileName) throws IOException { if (fileName == null) throw new IllegalArgumentException("No file name specified."); File f = new File(fileName); FileInputStream input = null; try { input = new FileInputStream(f); return new BufferedInputStream(input); } catch (Exception e) { if (input != null) input.close(); throw new IOException("Cannot read the file " + fileName + ". " + "Error: " + e.getMessage()); } } /** * Writes the file corresponding to the passed file name. Returns * the outputStream or <code>null</code> if the file cannot be created. * * @param fileName The name of the file to write. * @return See above. * @throws IOException If we cannot write the file or create a stream. */ public static OutputStream writeFile(String fileName) throws IOException { if (fileName == null) throw new IllegalArgumentException("No file name specified."); File f = new File(fileName); FileOutputStream out = null; try { out = new FileOutputStream(f); return new BufferedOutputStream(out); } catch (Exception e) { if (out != null) out.close(); throw new IOException("Cannot write the file " + fileName + ". " + "Error: " + e.getMessage()); } } /** * Reads the contents of the passed text file. * * @param file The file to handle. * @return See above. * @throws IOException If we cannot write the file or create a stream. */ public static String readTextFile(File file) throws IOException { StringBuffer contents = new StringBuffer(); BufferedReader input = new BufferedReader(new FileReader(file)); try { String line = null; while ((line = input.readLine()) != null) { contents.append(line); contents.append(System.getProperty("line.separator")); } } finally { input.close(); } return contents.toString(); } /** * Reads the contents of the passed text file. * * @param fileName The name of the file. * @return See above. * @throws IOException If we cannot write the file or create a stream. */ public static String readTextFile(String fileName) throws IOException { if (fileName == null) throw new IllegalArgumentException("No file name specified."); return readTextFile(new File(fileName)); } /** * Reads the contents of the passed file. * * @param file The file to handle. * @return See above. */ public static String readFile(File file) throws Exception { if (file == null) throw new IllegalArgumentException("No file name specified."); if (WORD_FILTER.accept(file)) return readWordFile(file); else if (EXCEL_FILTER.accept(file)) return readExcelFile(file); else if (PDF_FILTER.accept(file)) return readPDFFile(file); return null; } /** * Reads the contents of the passed text file. * * @param fileName The name of the file. * @return See above. * @throws IOException If we cannot write the file or create a stream. */ public static String readFile(String fileName) throws Exception { if (fileName == null || fileName.trim().length() == 0) throw new IllegalArgumentException("No file name specified."); return readFile(new File(fileName)); } /** * Returns an input stream for the contents of the passed configuration * file path. If we're running under Java Web Start, this input stream is * loaded from the CLASSPATH otherwise it is loaded directly. * * @param fileName The name of the file. * @return See above. * @throws IOException If we cannot create the input stream. */ public static InputStream readConfigFile(String fileName) throws IOException { if (isJavaWebStart()) { // We're running under Java Web Start, read configuration file // from the CLASSPATH. return IOUtil.class.getClassLoader().getResourceAsStream(fileName); } // We're running normally, return as so. return new FileInputStream(fileName); } /** * Returns <code>true</code> if the application is running under Java * Web Start, <code>false</code> otherwise. * * @return See above. */ public static boolean isJavaWebStart() { return System.getProperty("javawebstart.version", null) != null; } /** * Zips directory. * * @param directory The directory to zip. * @param out The output stream. * @throws Exception Thrown if an error occurred during the operation. */ private static void zipDir(File directory, ZipOutputStream out, String parentDirectoryName) throws Exception { File[] entries = directory.listFiles(); byte[] buffer = new byte[4096]; // Create a buffer for copying int bytesRead; FileInputStream in; File f; for (int i = 0; i < entries.length; i++) { f = entries[i]; if (f.isHidden()) continue; if (f.isDirectory()) { zipDir(f, out, f.getName()); continue; } in = new FileInputStream(f); // Stream to read file String zipName = f.getName(); if (!StringUtils.isEmpty(parentDirectoryName)) { zipName = FilenameUtils.concat(parentDirectoryName, zipName); } out.putNextEntry(new ZipEntry(zipName)); // Store entry while ((bytesRead = in.read(buffer)) != -1) out.write(buffer, 0, bytesRead); out.closeEntry(); in.close(); } } /** * Makes the zip. * * @param zipName The name of the zip. * @param compress Pass <code>true</code> to compress, * <code>false</code> otherwise. */ public static File zipDirectory(File zip, boolean compress) throws Exception { if (zip == null) throw new IllegalArgumentException("No name specified."); if (!zip.isDirectory() || !zip.exists()) throw new IllegalArgumentException("Not a valid directory."); //Check if the name already has the extension String extension = FilenameUtils.getExtension(zip.getName()); String name = zip.getName(); if (StringUtils.isEmpty(extension) || !ZIP_EXTENSION.equals("." + extension)) { name += ZIP_EXTENSION; } File file = new File(zip.getParentFile(), name); ZipOutputStream out = null; try { out = new ZipOutputStream(new FileOutputStream(file)); if (!compress) out.setLevel(ZipOutputStream.STORED); zipDir(zip, out, null); } catch (Exception e) { throw new Exception("Cannot create the zip.", e); } finally { if (out != null) out.close(); } return file; } /** * Makes the zip. * * @param zipName The name of the zip. */ public static File zipDirectory(File zip) throws Exception { return zipDirectory(zip, true); } /** * Extracts the specified jar name from the class path. * * @param name Value contained in the jar name. * @return See above. */ public static Map<String, InputStream> extractJarFromPath(String name) throws Exception { Map<String, InputStream> values = new HashMap<String, InputStream>(); if (name == null) return values; ClassLoader loader = IOUtil.class.getClassLoader(); if (isJavaWebStart()) loader = Thread.currentThread().getContextClassLoader(); //Get the URLs URL[] urls = ((URLClassLoader) loader).getURLs(); try { File f; String n; for (URL url : urls) { n = url.getFile(); f = new File(n); if (f.getName().contains(name)) { readJar(values, f); } } } catch (Exception e) { throw new Exception("Cannot read the requested jar.", e); } return values; } /** * Reads the specified jar file. * * @param values The values to add the entries to. * @param f The file to handle. * @throws Exception */ private static void readJar(Map<String, InputStream> values, File f) throws Exception { ZipFile zfile; Enumeration<? extends ZipEntry> entries; ZipEntry entry; zfile = new ZipFile(f); entries = zfile.entries(); while (entries.hasMoreElements()) { entry = entries.nextElement(); if (!entry.isDirectory()) { values.put(entry.getName(), zfile.getInputStream(entry)); } } } }