Java tutorial
/* Milyn - Copyright (C) 2006 This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (version 2.1) as published by the Free Software Foundation. This library 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 Lesser General Public License for more details: http://www.gnu.org/licenses/lgpl.txt */ import java.io.BufferedReader; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.Reader; import java.io.StringReader; /** * File utilities. * @author <a href="mailto:tom.fennelly@jboss.com">tom.fennelly@jboss.com</a> */ public abstract class FileUtils { public static void copyFile(String from, String to) throws IOException { File fromFile = new File(from); File toFile = new File(to); writeFile(readFile(fromFile), toFile); } /** * Read the contents of the specified file. * @param file The file to read. * @return The file contents. * @throws IOException Error readiong file. */ public static byte[] readFile(File file) throws IOException { if (!file.exists()) { throw new IllegalArgumentException("No such file '" + file.getAbsoluteFile() + "'."); } else if (file.isDirectory()) { throw new IllegalArgumentException( "File '" + file.getAbsoluteFile() + "' is a directory. Cannot read."); } InputStream stream = new FileInputStream(file); try { return StreamUtils.readStream(stream); } finally { stream.close(); } } public static void writeFile(byte[] bytes, File file) throws IOException { if (file.isDirectory()) { throw new IllegalArgumentException( "File '" + file.getAbsoluteFile() + "' is an existing directory. Cannot write."); } FileOutputStream stream = new FileOutputStream(file); try { stream.write(bytes); stream.flush(); } finally { stream.close(); } } } /* Milyn - Copyright (C) 2006 This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (version 2.1) as published by the Free Software Foundation. This library 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 Lesser General Public License for more details: http://www.gnu.org/licenses/lgpl.txt */ /** * Stream Utilities. * * @author tfennelly */ abstract class StreamUtils { /** * Read the supplied InputStream and return as a byte array. * * @param stream * The stream to read. * @return byte array containing the Stream data. * @throws IOException * Exception reading from the stream. */ public static byte[] readStream(InputStream stream) throws IOException { ByteArrayOutputStream bytesOut = new ByteArrayOutputStream(); byte[] byteBuf = new byte[1024]; int readCount = 0; while ((readCount = stream.read(byteBuf)) != -1) { bytesOut.write(byteBuf, 0, readCount); } return bytesOut.toByteArray(); } /** * Read the supplied InputStream and return as a byte array. * * @param stream * The stream to read. * @return A String containing the Stream data. * @throws IOException * Exception reading from the stream. */ public static String readStreamAsString(InputStream stream) throws IOException { return new String(readStream(stream)); } public static byte[] readFile(File file) throws IOException { InputStream stream = new FileInputStream(file); try { return readStream(stream); } finally { stream.close(); } } public static void writeFile(File file, byte[] data) throws IOException { OutputStream stream = new FileOutputStream(file); try { stream.write(data); } finally { try { stream.flush(); } finally { stream.close(); } } } public static String readStream(Reader stream) throws IOException { StringBuffer streamString = new StringBuffer(); char[] readBuffer = new char[256]; int readCount = 0; while ((readCount = stream.read(readBuffer)) != -1) { streamString.append(readBuffer, 0, readCount); } return streamString.toString(); } /** * Compares the 2 streams. * <p/> * Calls {@link #trimLines(InputStream)} on each stream before comparing. * @param s1 Stream 1. * @param s2 Stream 2. * @return True if the streams are equal not including leading and trailing * whitespace on each line and blank lines, otherwise returns false. */ public static boolean compareCharStreams(InputStream s1, InputStream s2) { StringBuffer s1Buf, s2Buf; try { s1Buf = trimLines(s1); s2Buf = trimLines(s2); return s1Buf.toString().equals(s2Buf.toString()); } catch (IOException e) { // fail the comparison } return false; } /** * Compares the 2 streams. * <p/> * Calls {@link #trimLines(java.io.Reader)} on each stream before comparing. * @param s1 Stream 1. * @param s2 Stream 2. * @return True if the streams are equal not including leading and trailing * whitespace on each line and blank lines, otherwise returns false. */ public static boolean compareCharStreams(Reader s1, Reader s2) { StringBuffer s1Buf, s2Buf; try { s1Buf = trimLines(s1); s2Buf = trimLines(s2); return s1Buf.toString().equals(s2Buf.toString()); } catch (IOException e) { // fail the comparison } return false; } /** * Compares the 2 streams. * <p/> * Calls {@link #trimLines(java.io.Reader)} on each stream before comparing. * @param s1 Stream 1. * @param s2 Stream 2. * @return True if the streams are equal not including leading and trailing * whitespace on each line and blank lines, otherwise returns false. */ public static boolean compareCharStreams(String s1, String s2) { return compareCharStreams(new StringReader(s1), new StringReader(s2)); } /** * Read the lines lines of characters from the stream and trim each line * i.e. remove all leading and trailing whitespace. * @param charStream Character stream. * @return StringBuffer containing the line trimmed stream. * @throws IOException */ public static StringBuffer trimLines(Reader charStream) throws IOException { StringBuffer stringBuf = new StringBuffer(); BufferedReader reader = new BufferedReader(charStream); String line; while ((line = reader.readLine()) != null) { stringBuf.append(line.trim()); } return stringBuf; } /** * Read the lines lines of characters from the stream and trim each line * i.e. remove all leading and trailing whitespace. * @param charStream Character stream. * @return StringBuffer containing the line trimmed stream. * @throws IOException */ public static StringBuffer trimLines(InputStream charStream) throws IOException { return trimLines(new InputStreamReader(charStream, "UTF-8")); } }