Merge pull request #15 from informatik-ag-ngl/f/enhanced_config

Migrated Config, ConfigItem and EnvoyLog from envoy-client

src/main/java/envoy/data/Config.java

@@ -0,0 +1,78 @@
+package envoy.data;
+
+import java.util.*;
+
+import envoy.exception.EnvoyException;
+
+/**
+ * Manages all application settings that are set during application startup by
+ * either loading them from the {@link Properties} file
+ * {@code client.properties} or parsing them from the command line arguments of
+ * the application.<br>
+ * <br>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>Config.java</strong><br>
+ * Created: <strong>12 Oct 2019</strong><br>
+ *
+ * @author Kai S. K. Engelbart
+ * @since Envoy Common v0.1-beta
+ */
+public class Config {
+
+	protected Map<String, ConfigItem<?>> items = new HashMap<>();
+
+	/**
+	 * Parses config items from a properties object.
+	 *
+	 * @param properties the properties object to parse
+	 * @since Envoy Common v0.1-beta
+	 */
+	public void load(Properties properties) {
+		items.entrySet()
+			.stream()
+			.filter(e -> properties.containsKey(e.getKey()))
+			.forEach(e -> e.getValue().parse(properties.getProperty(e.getKey())));
+	}
+
+	/**
+	 * Parses config items from an array of command line arguments.
+	 *
+	 * @param args the command line arguments to parse
+	 * @throws EnvoyException if the command line arguments contain an unknown token
+	 * @since Envoy Common v0.1-beta
+	 */
+	public void load(String[] args) throws EnvoyException {
+		for (int i = 0; i < args.length; i++)
+			for (ConfigItem<?> item : items.values())
+				if (args[i].startsWith("--")) {
+					if (args[i].length() == 2) throw new EnvoyException("Malformed command line argument at position " + i);
+					final String commandLong = args[i].substring(2);
+					if (item.getCommandLong().equals(commandLong)) {
+						item.parse(args[++i]);
+						break;
+					}
+				} else if (args[i].startsWith("-")) {
+					if (args[i].length() == 1) throw new EnvoyException("Malformed command line argument at position " + i);
+					final String commandShort = args[i].substring(1);
+					if (item.getCommandShort().equals(commandShort)) {
+						item.parse(args[++i]);
+						break;
+					}
+				} else throw new EnvoyException("Malformed command line argument at position " + i);
+	}
+
+	/**
+	 * @return {@code true} if all mandatory config items are initialized
+	 * @since Envoy Common v0.1-beta
+	 */
+	public boolean isInitialized() {
+		return items.values().stream().filter(ConfigItem::isMandatory).map(ConfigItem::get).noneMatch(Objects::isNull);
+	}
+
+	/**
+	 * @param name the name of the config item to return
+	 * @return the config item with the specified name
+	 * @since Envoy Common v0.1-beta
+	 */
+	public ConfigItem<?> get(String name) { return items.get(name); }
+}

src/main/java/envoy/data/ConfigItem.java

@@ -0,0 +1,92 @@
+package envoy.data;
+
+import java.util.function.Function;
+
+/**
+ * Contains a single {@link Config} value as well as the corresponding command
+ * line arguments and its default value.<br>
+ * <br>
+ * Project: <strong>envoy-clientChess</strong><br>
+ * File: <strong>ConfigItem.javaEvent.java</strong><br>
+ * Created: <strong>21.12.2019</strong><br>
+ *
+ * @author Kai S. K. Engelbart
+ * @param <T> the type of the config item's value
+ * @since Envoy Common v0.1-beta
+ */
+public class ConfigItem<T> {
+
+	private final String				commandLong, commandShort;
+	private final Function<String, T>	parseFunction;
+	private final boolean				mandatory;
+
+	private T value;
+
+	/**
+	 * Initializes a {@link ConfigItem}.
+	 *
+	 * @param commandLong   the long command line argument to set this value
+	 * @param commandShort  the short command line argument to set this value
+	 * @param parseFunction the {@code Function<String, T>} that parses the value
+	 *                      from a string
+	 * @param defaultValue  the optional default value to set before parsing
+	 * @param mandatory     indicated that this config item must be initialized with
+	 *                      a non-null value
+	 * @since Envoy Common v0.1-beta
+	 */
+	public ConfigItem(String commandLong, String commandShort, Function<String, T> parseFunction, T defaultValue, boolean mandatory) {
+		this.commandLong	= commandLong;
+		this.commandShort	= commandShort;
+		this.parseFunction	= parseFunction;
+		this.mandatory		= mandatory;
+		value				= defaultValue;
+	}
+
+	/**
+	 * Initializes an optional {@link ConfigItem} without a default value.
+	 *
+	 * @param commandLong   the long command line argument to set this value
+	 * @param commandShort  the short command line argument to set this value
+	 * @param parseFunction the {@code Function<String, T>} that parses the value
+	 *                      from a string
+	 * @since Envoy Common v0.1-beta
+	 */
+	public ConfigItem(String commandLong, String commandShort, Function<String, T> parseFunction) {
+		this(commandLong, commandShort, parseFunction, null, false);
+	}
+
+	/**
+	 * Parses this {@ConfigItem}'s value from a string.
+	 *
+	 * @param input the string to parse from
+	 * @since Envoy Common v0.1-beta
+	 */
+	public void parse(String input) { value = parseFunction.apply(input); }
+
+	/**
+	 * @return The long command line argument to set the value of this
+	 *         {@link ConfigItem}
+	 * @since Envoy Common v0.1-beta
+	 */
+	public String getCommandLong() { return commandLong; }
+
+	/**
+	 * @return The short command line argument to set the value of this
+	 *         {@link ConfigItem}
+	 * @since Envoy Common v0.1-beta
+	 */
+	public String getCommandShort() { return commandShort; }
+
+	/**
+	 * @return the value of this {@link ConfigItem}
+	 * @since Envoy Common v0.1-beta
+	 */
+	public T get() { return value; }
+
+	/**
+	 * @return {@code true} if this {@link ConfigItem} is mandatory for successful
+	 *         application initialization
+	 * @since Envoy Common v0.1-beta
+	 */
+	public boolean isMandatory() { return mandatory; }
+}

src/main/java/envoy/util/EnvoyLog.java

@@ -0,0 +1,118 @@
+package envoy.util;
+
+import java.io.File;
+import java.io.IOException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.logging.*;
+
+import envoy.data.Config;
+
+/**
+ * Configures the {@link java.util.logging} API to output the log into the
+ * console and a log file.<br>
+ * <br>
+ * Call the {@link EnvoyLog#attach(String)} method to configure a part of the
+ * logger hierarchy.<br>
+ * <br>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>EnvoyLogger.java</strong><br>
+ * Created: <strong>14 Dec 2019</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @author Kai S. K. Engelbart
+ * @since Envoy Common v0.1-beta
+ */
+public class EnvoyLog {
+
+	private static FileHandler		fileHandler;
+	private static StreamHandler	consoleHandler;
+	private static boolean			initialized;
+
+	private EnvoyLog() {}
+
+	/**
+	 * Initializes logging. Call this method before calling the
+	 * {@link EnvoyLog#attach(String)} method.
+	 *
+	 * @param config the config providing the console and log file barriers
+	 * @since Envoy Common v0.1-beta
+	 */
+	public static void initialize(Config config) {
+		if (initialized) throw new IllegalStateException("EnvoyLog is already initialized");
+
+		// Remove default console handler
+		LogManager.getLogManager().reset();
+
+		// Configure log file
+		File logFile = new File((File) config.get("homeDirectory").get(),
+				"log/envoy_user_" + new SimpleDateFormat("yyyy-MM-dd--hh-mm-mm").format(new Date()) + ".log");
+		logFile.getParentFile().mkdirs();
+
+		// Configure formatting
+		System.setProperty("java.util.logging.SimpleFormatter.format", "[%1$tF %1$tT] [%4$-7s] [%3$s] %5$s %n");
+		SimpleFormatter formatter = new SimpleFormatter();
+
+		try {
+			fileHandler = new FileHandler(logFile.getAbsolutePath());
+			fileHandler.setLevel((Level) config.get("fileLevelBarrier").get());
+			fileHandler.setFormatter(formatter);
+		} catch (SecurityException | IOException e) {
+			e.printStackTrace();
+		}
+		consoleHandler = new StreamHandler(System.out, formatter);
+		consoleHandler.setLevel((Level) config.get("consoleLevelBarrier").get());
+		consoleHandler.setFormatter(formatter);
+
+		initialized = true;
+	}
+
+	/**
+	 * Configures all loggers that are contained within the hierarchy of a specific
+	 * path to use the console and file handlers.
+	 *
+	 * @param path the path to the loggers to configure
+	 * @since Envoy Common v0.1-beta
+	 */
+	public static void attach(String path) {
+		if (!initialized) throw new IllegalStateException("EnvoyLog is not initialized");
+
+		// Get root logger
+		Logger logger = Logger.getLogger(path);
+
+		// Add handlers
+		if (fileHandler != null) logger.addHandler(fileHandler);
+		logger.addHandler(consoleHandler);
+
+		// Delegate logger level filtering to the handlers
+		logger.setLevel(Level.ALL);
+	}
+
+	/**
+	 * Creates a logger for a specified class, which output will be displayed inside
+	 * the console and written to the log file.
+	 *
+	 * @param logClass the class in which the logger is used
+	 * @return the created logger
+	 * @since Envoy Common v0.1-beta
+	 */
+	public static Logger getLogger(Class<?> logClass) { return Logger.getLogger(logClass.getCanonicalName()); }
+
+	/**
+	 * Defines the logger level required for a record to be written to the log file.
+	 *
+	 * @param fileLevelBarrier the log file level
+	 * @since Envoy Common v0.1-beta
+	 */
+	public static void setFileLevelBarrier(Level fileLevelBarrier) { if (fileHandler != null) fileHandler.setLevel(fileLevelBarrier); }
+
+	/**
+	 * Defines the logger level required for a record to be written to the console.
+	 *
+	 * @param consoleLevelBarrier the console logger level
+	 * @since Envoy Common v0.1-beta
+	 */
+	public static void setConsoleLevelBarrier(Level consoleLevelBarrier) {
+		if (consoleHandler != null) consoleHandler.setLevel(consoleLevelBarrier);
+	}
+}