Java tutorial
/** * Copyright (C) 2007 - 2014 52North Initiative for Geospatial Open Source * Software GmbH * * 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 org.n52.wps.io; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileFilter; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import java.util.UUID; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.TransformerException; import org.apache.commons.codec.binary.Base64InputStream; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.apache.xpath.XPathAPI; import org.w3c.dom.DOMException; import org.w3c.dom.Document; import org.xml.sax.SAXException; import static org.apache.commons.io.IOUtils.*; public class IOUtils { /** * Reads the given input stream as a string and decodes that base64 string * into a file with the specified extension * * @param input * the stream with the base64 string * @param extension * the extension of the result file (without the '.' at the * beginning) * @return the decoded base64 file written to disk * @throws IOException * if an error occurs while writing the contents to disk */ private static Logger LOGGER = LoggerFactory.getLogger(IOUtils.class); public static File writeBase64ToFile(InputStream input, String extension) throws IOException { File file = File.createTempFile("file" + UUID.randomUUID(), "." + extension, new File(System.getProperty("java.io.tmpdir"))); OutputStream outputStream = null; try { outputStream = new FileOutputStream(file); copyLarge(new Base64InputStream(input), outputStream); } finally { closeQuietly(outputStream); } return file; } public static File writeStreamToFile(InputStream inputStream, String extension) throws IOException { File file = File.createTempFile("file" + UUID.randomUUID(), "." + extension); return writeStreamToFile(inputStream, extension, file); } public static File writeStreamToFile(InputStream inputStream, String extension, File file) throws IOException { FileOutputStream output = new FileOutputStream(file); byte buf[] = new byte[1024]; int len; while ((len = inputStream.read(buf)) > 0) { output.write(buf, 0, len); } output.close(); inputStream.close(); return file; } public static File writeBase64XMLToFile(InputStream stream, String extension) throws SAXException, IOException, ParserConfigurationException, DOMException, TransformerException { // ToDo: look at StAX to stream XML parsing instead of in memory DOM Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(stream); String binaryContent = XPathAPI.selectSingleNode(document.getFirstChild(), "text()").getTextContent(); InputStream byteStream = null; try { byteStream = new ByteArrayInputStream(binaryContent.getBytes()); return writeBase64ToFile(byteStream, extension); } finally { closeQuietly(byteStream); } } /** * Zip the files. Returns a zipped file and delete the specified files * * @param files * files to zipped * @return the zipped file * @throws IOException * if the zipping process fails. */ public static File zip(File... files) throws IOException { File zip = File.createTempFile("zip" + UUID.randomUUID(), ".zip"); ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zip)); byte[] buffer = new byte[4096]; for (File file : files) { if (!file.exists()) { LOGGER.debug("Could not zip " + file.getAbsolutePath()); continue; } out.putNextEntry(new ZipEntry(file.getName())); FileInputStream in = new FileInputStream(file); int len; while ((len = in.read(buffer)) > 0) { out.write(buffer, 0, len); } out.closeEntry(); in.close(); } deleteResources(files); out.close(); return zip; } /** * Unzip the file. Returns the unzipped file with the specified extension * and deletes the zipped file * * @param file * the file to unzip * @param extension * the extension to search in the content files * @return the file with the specified extension * @throws IOException * if the unzipping process fails */ public static List<File> unzip(File file, String extension) throws IOException { return unzip(file, extension, null); } public static List<File> unzip(File file, String extension, File directory) throws IOException { int bufferLength = 2048; byte buffer[] = new byte[bufferLength]; List<File> foundFiles = new ArrayList<File>(); ZipInputStream zipInputStream = new ZipInputStream(new BufferedInputStream(new FileInputStream(file))); ZipEntry entry; File tempDir = directory; if (tempDir == null || !directory.isDirectory()) { tempDir = File.createTempFile("unzipped" + UUID.randomUUID(), "", new File(System.getProperty("java.io.tmpdir"))); tempDir.delete(); tempDir.mkdir(); } while ((entry = zipInputStream.getNextEntry()) != null) { int count; File entryFile = new File(tempDir, entry.getName()); entryFile.createNewFile(); FileOutputStream fos = new FileOutputStream(entryFile); BufferedOutputStream dest = new BufferedOutputStream(fos, bufferLength); while ((count = zipInputStream.read(buffer, 0, bufferLength)) != -1) { dest.write(buffer, 0, count); } dest.flush(); dest.close(); if (entry.getName().endsWith("." + extension)) { foundFiles.add(entryFile); } } zipInputStream.close(); deleteResources(file); return foundFiles; } public static List<File> unzipAll(File file) throws IOException { int bufferLength = 2048; byte buffer[] = new byte[bufferLength]; List<File> foundFiles = new ArrayList<File>(); ZipInputStream zipInputStream = new ZipInputStream(new BufferedInputStream(new FileInputStream(file))); ZipEntry entry; File tempDir = File.createTempFile("unzipped" + UUID.randomUUID(), "", new File(System.getProperty("java.io.tmpdir"))); tempDir.delete(); tempDir.mkdir(); while ((entry = zipInputStream.getNextEntry()) != null) { int count; File entryFile = new File(tempDir, entry.getName()); entryFile.createNewFile(); FileOutputStream fos = new FileOutputStream(entryFile); BufferedOutputStream dest = new BufferedOutputStream(fos, bufferLength); while ((count = zipInputStream.read(buffer, 0, bufferLength)) != -1) { dest.write(buffer, 0, count); } dest.flush(); dest.close(); foundFiles.add(entryFile); } zipInputStream.close(); deleteResources(file); return foundFiles; } /** * Delete the given files and all the files with the same name but different * extension. If some file is <code>null</code> just doesn't process it and * continue to the next element of the array * * @param files * the files to delete */ public static void deleteResources(File... files) { for (File file : files) { if (file != null) { if (file.getAbsolutePath().startsWith(System.getProperty("java.io.tmpdir"))) { delete(file); File parent = file.getAbsoluteFile().getParentFile(); if (parent != null && !(parent.getAbsolutePath().equals(System.getProperty("java.io.tmpdir")))) { parent.deleteOnExit(); } } } } } /** * Delete the given files and all the files with the same name but different * extension. If some file is <code>null</code> just doesn't process it and * continue to the next element of the array * * @param files * the files to delete */ private static void delete(File... files) { for (File file : files) { if (file != null) { final String baseName = file.getName().substring(0, file.getName().lastIndexOf(".")); File[] list = file.getAbsoluteFile().getParentFile().listFiles(new FileFilter() { @Override public boolean accept(File pathname) { return pathname.getName().startsWith(baseName); } }); for (File f : list) { f.deleteOnExit(); } file.deleteOnExit(); } } } }