Java tutorial
/* * Copyright 2011 b1.org * * 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.b1.pack.cli; import com.google.common.base.Preconditions; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import com.google.common.io.Files; import org.b1.pack.api.builder.Writable; import org.b1.pack.api.common.FolderContent; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.*; public class FileTools { public static void saveToFile(Writable writable, File file) throws IOException { File tempFile = createTempFile(file); FileOutputStream stream = new FileOutputStream(tempFile); try { writable.writeTo(stream, 0, writable.getSize()); } finally { stream.close(); } Files.move(tempFile, file); } public static File createTempFile(File file) throws IOException { File absoluteFile = file.getAbsoluteFile(); File parentFile = absoluteFile.getParentFile(); if (!parentFile.exists()) { if (!parentFile.mkdirs()) { throw new IOException("Cannot create: " + parentFile); } } return File.createTempFile(absoluteFile.getName() + "--", null, parentFile); } public static Set<FsObject> getFsObjects(List<String> names) { Map<List<String>, FsObject> map = createRootMap(names); Set<FsObject> result = Sets.newLinkedHashSet(); for (FsObject fsObject : map.values()) { addPrecedingObjects(result, fsObject, map); addObjectWithChildren(result, fsObject); } return result; } public static Map<List<String>, FsObject> createRootMap(List<String> names) { Map<List<String>, FsObject> map = Maps.newLinkedHashMap(); for (String name : names.isEmpty() ? Collections.singleton(".") : names) { File file = new File(name); List<String> path = getPath(file); Preconditions.checkState(map.put(path, new FsObject(file, path)) == null, "Duplicate path: %s", path); } return map; } public static List<String> getPath(File file) { LinkedList<String> result = Lists.newLinkedList(); do { String name = file.getName(); if (name.isEmpty() || name.equals(".") || name.equals("..")) { return result; } result.addFirst(name); file = file.getParentFile(); } while (file != null); return result; } private static void addPrecedingObjects(Set<FsObject> result, FsObject fsObject, Map<List<String>, FsObject> map) { List<String> path = fsObject.getPath(); for (int i = 1; i < path.size(); i++) { List<String> otherPath = path.subList(0, i); FsObject otherObject = map.get(otherPath); if (otherObject != null) { result.add(otherObject); } } } private static void addObjectWithChildren(Set<FsObject> result, FsObject fsObject) { if (!fsObject.getPath().isEmpty()) { result.add(fsObject); } File[] childen = fsObject.getFile().listFiles(); if (childen != null) { for (File child : childen) { addObjectWithChildren(result, new FsObject(child, asList(fsObject.getPath(), child.getName()))); } } } private static <T> List<T> asList(List<T> list, T tail) { List<T> result = new ArrayList<T>(list.size() + 1); result.addAll(list); result.add(tail); return result; } public static File getOutputFolder(ArgSet argSet) { String outputDirectory = argSet.getOutputDirectory(); if (outputDirectory == null) return null; File result = new File(outputDirectory); Preconditions.checkArgument(result.isDirectory(), "Output directory not found: %s", result); return result; } public static FolderContent createFolderContent(List<String> names) { return new FsFolderContent(names.isEmpty() ? Collections.singletonList(".") : names); } public static void setLastModified(File file, Long time) { Preconditions.checkState(time == null || file.setLastModified(time), "Cannot set time: %s", file); } }