Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 io.milton.common; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.BufferedReader; import org.apache.commons.io.output.ByteArrayOutputStream; import java.io.Closeable; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.List; import org.apache.commons.io.IOUtils; public class FileUtils { public void copy(File source, File dest) { FileInputStream is = null; FileOutputStream os = null; try { is = new FileInputStream(source); os = new FileOutputStream(dest); int i = is.read(); while (i >= 0) { os.write(i); i = is.read(); } } catch (FileNotFoundException ex) { ex.printStackTrace(); } catch (IOException ex) { ex.printStackTrace(); } finally { close(is); close(os); } } public static ByteArrayOutputStream readIn(InputStream is) throws IOException { ByteArrayOutputStream os = new ByteArrayOutputStream(); StreamUtils.readTo(is, os, true, true); return os; } public static String readResource(Class cl, String res) throws IOException { InputStream in = cl.getResourceAsStream(res); if (in == null) { throw new IOException( "Failed to read resource: " + res + " relative to class: " + cl.getCanonicalName()); } ByteArrayOutputStream out = readIn(in); return out.toString(); } public static void close(InputStream in) { try { if (in == null) { return; } in.close(); } catch (IOException ex) { } } public static void close(Closeable in) { try { if (in == null) { return; } in.close(); } catch (IOException ex) { } } public static void close(Object o) { if (o == null) { return; } // debug("Closing: " + o); try { Method m = o.getClass().getMethod("close"); m.invoke(o); } catch (IllegalArgumentException ex) { throw new RuntimeException(ex); } catch (SecurityException ex) { throw new RuntimeException(ex); } catch (IllegalAccessException ex) { throw new RuntimeException(ex); } catch (InvocationTargetException ex) { throw new RuntimeException(ex); } catch (NoSuchMethodException ex) { throw new RuntimeException(ex); } } public InputStream openFile(File file) throws FileNotFoundException { FileInputStream fin = null; BufferedInputStream br = null; fin = new FileInputStream(file); br = new BufferedInputStream(fin); return br; } public OutputStream openFileForWrite(File file) throws FileNotFoundException { FileOutputStream fout = new FileOutputStream(file); BufferedOutputStream bout = new BufferedOutputStream(fout); return bout; } public String readFile(File file) throws FileNotFoundException { FileReader fr = null; BufferedReader br = null; try { fr = new FileReader(file); br = new BufferedReader(fr); StringBuilder sb = new StringBuilder(); String s = null; while ((s = br.readLine()) != null) { sb.append(s); sb.append("\n"); } return sb.toString(); } catch (FileNotFoundException e) { throw e; } catch (IOException ex) { throw new RuntimeException(ex); } finally { close(br); close(fr); } } public String read(InputStream in) { try { BufferedInputStream bin = new BufferedInputStream(in); int s; byte[] buf = new byte[1024]; StringBuilder sb = new StringBuilder(); while ((s = bin.read(buf)) > -1) { sb.append(new String(buf, 0, s)); } return sb.toString(); } catch (IOException ex) { throw new RuntimeException(ex); } } public File resolveRelativePath(File start, String path) { String[] arr = path.split("/"); File f = start; for (String s : arr) { if (s.equals("..")) { f = f.getParentFile(); } else { f = new File(f, s); } } return f; } public static String getExtension(File file) { return getExtension(file.getName()); } public static String getExtension(String nm) { if (nm == null) { return null; } try { int pos = nm.lastIndexOf("."); if (pos > -1) { String ext = nm.substring(pos + 1); return ext; } else { return null; } } catch (Throwable e) { throw new RuntimeException(nm, e); } } public static String stripExtension(String nm) { if (nm.contains(".")) { String[] arr = nm.split("[.]"); StringBuilder sb = new StringBuilder(); for (int i = 0; i < arr.length - 1; i++) { if (arr[i] != null) { if (i != 0) { sb.append("."); } sb.append(arr[i]); } } return sb.toString(); } else { return nm; } } public static String preprendExtension(String filename, String newExt) { String ext = getExtension(filename); filename = stripExtension(filename); filename = filename + "." + newExt + "." + ext; return filename; } public static String incrementFileName(String name, boolean isFirst) { String mainName = stripExtension(name); String ext = getExtension(name); int count; if (isFirst) { count = 1; } else { int pos = mainName.lastIndexOf("("); if (pos > 0) { String sNum = mainName.substring(pos + 1, mainName.length() - 1); count = Integer.parseInt(sNum) + 1; mainName = mainName.substring(0, pos); } else { count = 1; } } String s = mainName + "(" + count + ")"; if (ext != null) { s = s + "." + ext; } return s; } /** * replace spaces with underscores * * @param s * @return */ public static String sanitiseName(String s) { s = s.replaceAll("[ ]", "_"); return s; } public static void readLines(File f, List<String> lines) { InputStream in = null; try { in = new FileInputStream(f); for (Object oLine : IOUtils.readLines(in)) { lines.add(oLine.toString()); } } catch (Exception e) { throw new RuntimeException(f.getAbsolutePath(), e); } finally { IOUtils.closeQuietly(in); } } public static void writeLines(File f, List<String> lines) { FileOutputStream fout = null; try { fout = new FileOutputStream(f); IOUtils.writeLines(lines, null, fout); } catch (Exception e) { throw new RuntimeException(f.getAbsolutePath(), e); } finally { IOUtils.closeQuietly(fout); } } }