Java tutorial
/* Copyright 2015 Alex Altoukhov 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 com.altoukhov.svsync; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import java.io.BufferedWriter; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStreamWriter; import java.io.Writer; import java.nio.ByteBuffer; import java.nio.charset.Charset; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Paths; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import org.joda.time.DateTime; import org.joda.time.DateTimeZone; import com.altoukhov.svsync.fileviews.IWriteableFileSpace; /** * @author Alex Altoukhov */ public class Snapshot implements IWriteableFileSpace { private static final GsonBuilder gsonBuilder = new GsonBuilder(); static { GsonSerializers serializers = new GsonSerializers(); gsonBuilder.registerTypeAdapter(DateTime.class, serializers.new DateTimeSerializer()); gsonBuilder.registerTypeAdapter(DateTime.class, serializers.new DateTimeDeserializer()); } private DateTime timestamp; private Map<String, FileSnapshot> files; private Set<String> directories; public Snapshot(Map<String, FileSnapshot> files, Set<String> dirs) { this.files = files; this.directories = dirs; this.timestamp = DateTime.now(DateTimeZone.UTC); } public DateTime getTimestamp() { return timestamp; } public Map<String, FileSnapshot> getFiles() { return files; } public Set<String> getDirectories() { return directories; } public long size() { long size = 0; for (FileSnapshot file : files.values()) { size += file.getFileSize(); } return size; } public static Diff diff(Snapshot source, Snapshot target, boolean detectMovedFiles) { Diff diff = new Diff(); Collection<FileSnapshot> changed = diff.getFileChanges(Diff.DiffType.CHANGED); Collection<FileSnapshot> added = diff.getFileChanges(Diff.DiffType.ADDED); Collection<FileSnapshot> deleted = diff.getFileChanges(Diff.DiffType.DELETED); Collection<FileSnapshot> moved = diff.getFileChanges(Diff.DiffType.MOVED); Collection<String> dirAdded = diff.getDirectoryChanges(Diff.DiffType.ADDED); Collection<String> dirDeleted = diff.getDirectoryChanges(Diff.DiffType.DELETED); for (String filePath : target.files.keySet()) { if (source.files.containsKey(filePath)) { FileSnapshot fromFile = source.files.get(filePath); FileSnapshot toFile = target.files.get(filePath); if (!toFile.equals(fromFile)) { changed.add(fromFile); } } else { deleted.add(target.files.get(filePath)); } } for (String filePath : source.files.keySet()) { if (!target.files.containsKey(filePath)) { added.add(source.files.get(filePath)); } } if (detectMovedFiles) { // Find moved items Set<FileSnapshot> movedFiles = new HashSet<>(added); movedFiles.retainAll(deleted); if (!movedFiles.isEmpty()) { Map<FileSnapshot, List<FileSnapshot>> movedFromMap = new HashMap<>(); Map<FileSnapshot, List<FileSnapshot>> movedToMap = new HashMap<>(); for (FileSnapshot file : deleted) { if (movedFiles.contains(file)) { if (!movedFromMap.containsKey(file)) { movedFromMap.put(file, new ArrayList<FileSnapshot>()); } movedFromMap.get(file).add(file); } } for (FileSnapshot file : added) { if (movedFiles.contains(file)) { if (!movedToMap.containsKey(file)) { movedToMap.put(file, new ArrayList<FileSnapshot>()); } movedToMap.get(file).add(file); } } // Remove from added/deleted added.removeAll(movedFiles); deleted.removeAll(movedFiles); for (FileSnapshot file : movedFiles) { List<FileSnapshot> fromList = movedFromMap.get(file); List<FileSnapshot> toList = movedToMap.get(file); int i; for (i = 0; i < Math.min(fromList.size(), toList.size()); i++) { FileSnapshot movedFile = toList.get(i); movedFile.setPreviousPath(fromList.get(i).getRelativePath()); moved.add(movedFile); } while (i < fromList.size()) { deleted.add(fromList.get(i)); i++; } while (i < toList.size()) { added.add(toList.get(i)); i++; } } } } // Find directory changes for (String dir : source.directories) { if (!target.directories.contains(dir)) { dirAdded.add(dir); } } for (String dir : target.directories) { if (!source.directories.contains(dir)) { dirDeleted.add(dir); } } diff.setStat(new Stat(source, target, diff)); return diff; } private static Snapshot fromJson(String json) { Gson g = gsonBuilder.create(); return g.fromJson(json, Snapshot.class); } public static Snapshot fromFile(String path) { try { if (!(new File(path)).exists()) return null; String content = readFile(path, StandardCharsets.UTF_8); return fromJson(content); } catch (Exception ex) { System.out.println(ex.getMessage()); return null; } } private String toJson() { Gson g = gsonBuilder.setPrettyPrinting().create(); return g.toJson(this); } public boolean toFile(String path) { Writer out = null; try { out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(path), "UTF-8")); out.write(toJson()); } catch (IOException ex) { System.out.println(ex.getMessage()); return false; } finally { try { if (out != null) { out.close(); } } catch (IOException ex) { System.out.println(ex.getMessage()); } } return true; } private static String readFile(String path, Charset encoding) throws IOException { byte[] encoded = Files.readAllBytes(Paths.get(path)); return encoding.decode(ByteBuffer.wrap(encoded)).toString(); } @Override public boolean createDirectory(String path) { return directories.add(path); } @Override public boolean deleteDirectory(String path) { return directories.remove(path); } @Override public boolean deleteFile(String path) { files.remove(path); return true; } @Override public boolean writeFile(InputStream fileStream, FileSnapshot file) { files.put(file.getRelativePath(), file); return true; } @Override public boolean isMoveFileSupported() { return true; } @Override public boolean moveFile(String oldPath, String newPath) { if (files.containsKey(oldPath)) { FileSnapshot file = files.get(oldPath); FileSnapshot newFile = new FileSnapshot(file.getFileName(), file.getFileSize(), file.getModifiedTimestamp(), newPath); files.remove(oldPath); files.put(newPath, newFile); return true; } return false; } }