Add option to save command line logs (#102)

* Add logger that uses java.util.Logger
* Add file log handler and options to save command line log
* Support subdirectories and only use LoggerLogger as global log when saving the log file

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/logger/LoggerLogger.java

@@ -0,0 +1,107 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.core.logger;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Paths;
+import java.util.logging.ConsoleHandler;
+import java.util.logging.FileHandler;
+import java.util.logging.Level;
+import java.util.logging.LogRecord;
+import java.util.logging.Logger;
+import java.util.logging.SimpleFormatter;
+import org.apache.commons.lang3.exception.ExceptionUtils;
+
+public class LoggerLogger extends AbstractLogger {
+	private static LoggerLogger instance = null;
+	
+	private Logger logger;
+	private SimpleFormatter formatter;
+
+	private LoggerLogger() {
+		this.logger = Logger.getLogger("bluemap");
+		this.logger.setUseParentHandlers(false);
+		ConsoleHandler cHandler = new ConsoleHandler();
+		formatter = new SimpleFormatter() {
+			@Override
+			public synchronized String format(LogRecord record) {
+				String stackTrace = record.getThrown() == null ? "" : ExceptionUtils.getStackTrace(record.getThrown());
+				return String.format("[%1$s] %2$s%3$s%n", record.getLevel(), record.getMessage(), stackTrace);
+			}
+		};
+		cHandler.setFormatter(formatter);
+		this.logger.addHandler(cHandler);
+		
+	}
+	
+	public static LoggerLogger getInstance() {
+		if (instance == null) {
+			instance = new LoggerLogger();
+		}
+		return instance;
+	}
+	
+	public void addFileHandler(String filename, boolean append) {
+		try {
+			FileHandler fHandler = new FileHandler(filename, append);
+			fHandler.setFormatter(formatter);
+			this.logger.addHandler(fHandler);
+		} catch (NoSuchFileException e) {
+			// Directory may not exist. Create it and try again.
+			File parent = Paths.get(e.getFile()).getParent().toFile();
+			if (!parent.exists()) {
+				parent.mkdirs();
+				addFileHandler(filename, append);
+			} else {
+				de.bluecolored.bluemap.core.logger.Logger.global.logError("Error while opening log file!", e);
+			}
+		} catch (IOException e) {
+			de.bluecolored.bluemap.core.logger.Logger.global.logError("Error while opening log file!", e);
+		}
+	}
+
+	@Override
+	public void logError(String message, Throwable throwable) {
+		logger.log(Level.SEVERE, message, throwable);
+	}
+
+	@Override
+	public void logWarning(String message) {
+		logger.log(Level.WARNING, message);
+	}
+
+	@Override
+	public void logInfo(String message) {
+		logger.log(Level.INFO, message);
+	}
+
+	@Override
+	public void logDebug(String message) {
+		logger.log(Level.FINE, message);
+	}
+	
+}

implementations/cli/src/main/java/de/bluecolored/bluemap/cli/BlueMapCLI.java

@@ -57,6 +57,7 @@
 import de.bluecolored.bluemap.core.MinecraftVersion;
 import de.bluecolored.bluemap.core.config.WebServerConfig;
 import de.bluecolored.bluemap.core.logger.Logger;
+import de.bluecolored.bluemap.core.logger.LoggerLogger;
 import de.bluecolored.bluemap.core.metrics.Metrics;
 import de.bluecolored.bluemap.core.render.hires.HiresModelManager;
 import de.bluecolored.bluemap.core.web.FileRequestHandler;
@@ -254,6 +255,11 @@ public static void main(String[] args) {
 		try {
 			CommandLine cmd = parser.parse(BlueMapCLI.createOptions(), args, false);
 			
+			if (cmd.hasOption("l")) {
+				Logger.global = LoggerLogger.getInstance();
+				((LoggerLogger) Logger.global).addFileHandler(cmd.getOptionValue("l"), cmd.hasOption("a"));
+			}
+			
 			//help
 			if (cmd.hasOption("h")) {
 				BlueMapCLI.printHelp();
@@ -375,6 +381,16 @@ private static Options createOptions() {
 				.desc("Sets the minecraft-version, used e.g. to load resource-packs correctly. Defaults to the latest compatible version.")
 				.build()
 			);
+		
+		options.addOption(
+				Option.builder("l")
+				.longOpt("log-file")
+				.hasArg()
+				.argName("file-name")
+				.desc("Sets a file to save the log to. If not specified, no log will be saved.")
+				.build()
+			);
+		options.addOption("a", "append", false, "Causes log save file to be appended rather than replaced.");
 
 		options.addOption("w", "webserver", false, "Starts the web-server, configured in the 'webserver.conf' file");
 		options.addOption("b", "verbose", false, "Causes the web-server to log requests to the console");