Java tutorial
/* * DavMail POP/IMAP/SMTP/CalDav/LDAP Exchange Gateway * Copyright (C) 2010 Mickael Guessant * * 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 davmail.util; import org.apache.commons.codec.binary.Base64; import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.*; /** * Input output functions. */ public final class IOUtil { private IOUtil() { } /** * Write all inputstream content to outputstream. * * @param inputStream input stream * @param outputStream output stream * @throws IOException on error */ public static void write(InputStream inputStream, OutputStream outputStream) throws IOException { byte[] bytes = new byte[8192]; int length; while ((length = inputStream.read(bytes)) > 0) { outputStream.write(bytes, 0, length); } } /** * Decode base64 input string, return byte array. * * @param encoded Base64 encoded string * @return decoded content as byte arrey * @throws IOException on error */ public static byte[] decodeBase64(String encoded) throws IOException { return Base64.decodeBase64(encoded.getBytes("ASCII")); } /** * Decode base64 input string, return content as UTF-8 String. * * @param encoded Base64 encoded string * @return decoded content as byte arrey * @throws IOException on error */ public static String decodeBase64AsString(String encoded) throws IOException { return new String(decodeBase64(encoded), "UTF-8"); } /** * Base64 encode value. * * @param value input value * @return base64 value * @throws IOException on error */ public static String encodeBase64AsString(String value) throws IOException { return new String(Base64.encodeBase64(value.getBytes("UTF-8")), "ASCII"); } /** * Base64 encode value. * * @param value input value * @return base64 value * @throws IOException on error */ public static String encodeBase64AsString(byte[] value) throws IOException { return new String(Base64.encodeBase64(value), "ASCII"); } /** * Base64 encode value. * * @param value input value * @return base64 value * @throws IOException on error */ public static byte[] encodeBase64(String value) throws IOException { return Base64.encodeBase64(value.getBytes("UTF-8")); } /** * Base64 encode value. * * @param value input value * @return base64 value */ public static byte[] encodeBase64(byte[] value) { return Base64.encodeBase64(value); } /** * Resize image bytes to a max width or height image size. * * @param inputBytes input image bytes * @param max max size * @return scaled image bytes * @throws IOException on error */ public static byte[] resizeImage(byte[] inputBytes, int max) throws IOException { BufferedImage inputImage = ImageIO.read(new ByteArrayInputStream(inputBytes)); if (inputImage == null) { throw new IOException("Unable to decode image data"); } BufferedImage outputImage = resizeImage(inputImage, max); ByteArrayOutputStream baos = new ByteArrayOutputStream(); ImageIO.write(outputImage, "jpg", baos); return baos.toByteArray(); } /** * Resize image to a max width or height image size. * * @param inputImage input image * @param max max size * @return scaled image */ public static BufferedImage resizeImage(BufferedImage inputImage, int max) { int width = inputImage.getWidth(); int height = inputImage.getHeight(); int targetWidth; int targetHeight; if (width <= max && height <= max) { return inputImage; } else if (width > height) { targetWidth = max; targetHeight = targetWidth * height / width; } else { targetHeight = max; targetWidth = targetHeight * width / height; } Image scaledImage = inputImage.getScaledInstance(targetWidth, targetHeight, Image.SCALE_SMOOTH); BufferedImage targetImage = new BufferedImage(targetWidth, targetHeight, BufferedImage.TYPE_INT_RGB); targetImage.getGraphics().drawImage(scaledImage, 0, 0, null); return targetImage; } /** * Read all inputStream content to a byte array. * * @param inputStream input stream * @return content as byte array * @throws IOException on error */ public static byte[] readFully(InputStream inputStream) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] bytes = new byte[8192]; int length; while ((length = inputStream.read(bytes)) > 0) { baos.write(bytes, 0, length); } return baos.toByteArray(); } }