Added functionality to archive list of saves when the game server exits.

The number of saves that will be archived can be modified using
max_archive_size in config.properties. Added shutdown hook to Main.java
to handle dumping of zip files. Essential functions are in
ZipUtils.java.

Server/src/main/java/net/simon987/server/GameServer.java

@@ -1,6 +1,5 @@
 package net.simon987.server;
 
-
 import net.simon987.server.event.GameEvent;
 import net.simon987.server.event.GameEventDispatcher;
 import net.simon987.server.event.TickEvent;
@@ -33,6 +32,10 @@ public class GameServer implements Runnable {
 
 	private int maxExecutionTime;
 
+	public ArrayList<byte[]> saveArchive;
+	
+	public int maxArchiveSize;
+
 	public GameServer() {
 
 		this.config = new ServerConfiguration(new File("config.properties"));
@@ -42,7 +45,7 @@ public class GameServer implements Runnable {
 
 		maxExecutionTime = config.getInt("user_timeout");
 
-        //Load all plugins in plugins folder, if it doesn't exist, create it
+		// Load all plugins in plugins folder, if it doesn't exist, create it
 		File pluginDir = new File("plugins/");
 		File[] pluginDirListing = pluginDir.listFiles();
 
@@ -62,6 +65,9 @@ public class GameServer implements Runnable {
 
 		eventDispatcher = new GameEventDispatcher(pluginManager);
 		
+		saveArchive = new ArrayList<byte[]>();
+		
+		maxArchiveSize = config.getInt("max_archive_size");
 	}
 
 	public GameUniverse getGameUniverse() {
@@ -76,9 +82,9 @@ public class GameServer implements Runnable {
 	public void run() {
 		LogManager.LOGGER.info("(G) Started game loop");
 
-        long startTime; //Start time of the loop
-        long uTime;     //update time
-        long waitTime;  //time to wait
+		long startTime; // Start time of the loop
+		long uTime; // update time
+		long waitTime; // time to wait
 
 		boolean running = true;
 
@@ -91,7 +97,8 @@ public class GameServer implements Runnable {
 			uTime = System.currentTimeMillis() - startTime;
 			waitTime = config.getInt("tick_length") - uTime;
 
-            LogManager.LOGGER.info("Wait time : " + waitTime + "ms | Update time: " + uTime + "ms | " + (int) (((double) uTime / waitTime) * 100) + "% load");
+			LogManager.LOGGER.info("Wait time : " + waitTime + "ms | Update time: " + uTime + "ms | "
+					+ (int) (((double) uTime / waitTime) * 100) + "% load");
 
 			try {
 				if (waitTime >= 0) {
@@ -103,18 +110,16 @@ public class GameServer implements Runnable {
 
 		}
 
-
 	}
 
 	private void tick() {
 		gameUniverse.incrementTime();
 
-        //Dispatch tick event
+		// Dispatch tick event
 		GameEvent event = new TickEvent(gameUniverse.getTime());
-        GameServer.INSTANCE.getEventDispatcher().dispatch(event); //Ignore cancellation
+		GameServer.INSTANCE.getEventDispatcher().dispatch(event); // Ignore cancellation
 
-
-        //Process user code
+		// Process user code
 		ArrayList<User> users_ = gameUniverse.getUsers();
 		for (User user : users_) {
 
@@ -135,14 +140,14 @@ public class GameServer implements Runnable {
 			}
 		}
 
-        //Process each worlds
-        //Avoid concurrent modification
+		// Process each worlds
+		// Avoid concurrent modification
 		ArrayList<World> worlds = new ArrayList<>(gameUniverse.getWorlds());
 		for (World world : worlds) {
 			world.update();
 		}
 
-        //Save
+		// Save
 		if (gameUniverse.getTime() % config.getInt("save_interval") == 0) {
 			save(new File("save.json"));
 		}
@@ -155,10 +160,18 @@ public class GameServer implements Runnable {
 	/**
 	 * Save game universe to file in JSON format
 	 *
-     * @param file JSON file to save
+	 * @param file
+	 *            JSON file to save
 	 */
 	public void save(File file) {
 
+		if (new File(new File("save.json").getAbsolutePath()).exists()) {
+			saveArchive.add(ZipUtils.bytifyFile("save.json"));
+			while(saveArchive.size() > maxArchiveSize) {
+				saveArchive.remove(0);
+			}
+		}
+		
 		try {
 			FileWriter fileWriter = new FileWriter(file);
 
@@ -194,4 +207,8 @@ public class GameServer implements Runnable {
 	public void setSocketServer(SocketServer socketServer) {
 		this.socketServer = socketServer;
 	}
+	
+	public ArrayList<byte[]> getSaveArchive() {
+		return this.saveArchive;
+	}
 }

Server/src/main/java/net/simon987/server/Main.java

@@ -4,12 +4,24 @@ import net.simon987.server.logging.LogManager;
 import net.simon987.server.webserver.SocketServer;
 
 import java.io.File;
+import java.io.IOException;
 import java.net.InetSocketAddress;
 
 
 public class Main {
     public static void main(String[] args) {
 
+    	//Writes all of the files stored in GameServer.saveArray to a zip file.
+        Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
+            public void run() {
+                try {
+					ZipUtils.writeSavesToZip(GameServer.INSTANCE.getSaveArchive());
+				} catch (IOException e) {
+					System.out.println("Error writing saves to zip");
+					e.printStackTrace();
+				}
+            }
+        }, "Shutdown-thread"));
 
         LogManager.initialize();
         ServerConfiguration config = new ServerConfiguration(new File("config.properties"));

Server/src/main/java/net/simon987/server/ZipUtils.java

@@ -0,0 +1,91 @@
+package net.simon987.server;
+
+import java.io.ByteArrayInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import net.simon987.server.logging.LogManager;
+
+public class ZipUtils {
+
+	private static final int BUFFER_SIZE = 1024;
+
+	public static byte[] bytifyFile(String fileName) {
+
+		Path path = Paths.get(fileName);
+		byte[] bytes = null;
+
+		try {
+			bytes = Files.readAllBytes(path);
+
+		} catch (IOException e) {
+			System.out.println("Failed to extract bytes from: " + fileName);
+			e.printStackTrace();
+		}
+
+		return bytes;
+	}
+	
+	public static String getByteArrAsString(byte[] bytes) throws UnsupportedEncodingException {
+		return new String(bytes, "UTF-8");
+	}
+
+	public static void writeSavesToZip(ArrayList<byte[]> array) throws IOException {
+		
+		int writeCount = 0;
+		FileOutputStream output = new FileOutputStream("archive_" + getDateTimeStamp() + ".zip");
+		ZipOutputStream stream = new ZipOutputStream(output);
+		byte[] buffer = new byte[BUFFER_SIZE];
+		ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
+
+		while ((bais.read(buffer)) > -1) {
+			for (int i = 0; i < array.size(); i++) {
+
+				ZipEntry entry = new ZipEntry("save_" + getTickTime(array.get(i)) + ".json");
+				stream.putNextEntry(entry);
+				stream.write(array.get(i));
+				stream.closeEntry();
+				writeCount++;
+			}
+		}
+
+		stream.close();
+		output.close();
+		
+		LogManager.LOGGER.info(writeCount + " saves moved to zip file archive");
+	}
+
+	private static String getTickTime(byte[] bytes) throws UnsupportedEncodingException {
+
+		Pattern pattern = Pattern.compile("\"time\"");
+		String stringedBytes = getByteArrAsString(bytes);
+		Matcher matcher = pattern.matcher(stringedBytes);
+		int startIndex = 0;
+		
+		while (matcher.find()) {
+			startIndex = matcher.end() + 1;
+		}
+		
+		int endIndex = stringedBytes.indexOf(",", startIndex);
+		
+		return stringedBytes.substring(startIndex, endIndex);
+	}
+	
+	private static String getDateTimeStamp() {
+		Date millisToDate = new Date(System.currentTimeMillis());
+		SimpleDateFormat f = new SimpleDateFormat("yyyyMMddHHmmss");    
+		return f.format(millisToDate);
+	}
+
+}

config.properties

@@ -63,3 +63,6 @@ wg_maxCopperCount=2
 user_timeout=500
 # Free CPU execution time in ms
 user_free_execution_time=2
+# ----------------------------------------------
+# Max saves to archive when the server is shutdown
+max_archive_size=10