simple-logger v1.0

src/main/java/fr/klemek/logger/Logger.java

@@ -0,0 +1,172 @@
+package fr.klemek.logger;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Locale;
+import java.util.logging.Level;
+import java.util.logging.LogManager;
+
+/**
+ * Simple logger for this application.
+ *
+ * @author Clement Gouin
+ */
+public final class Logger {
+
+    private static java.util.logging.Logger appLogger = java.util.logging.Logger.getLogger(Utils.getString("app_name","Unkown"));
+    private static final String APP_NAME = Utils.getString("app_name","Unkown");
+    private static final String BASE_PACKAGE = Utils.getString("default_package",null);
+    private static final int DEFAULT_DEPTH = 4;
+
+    private static boolean initialized = false;
+
+    private Logger() {
+    }
+
+    /**
+     * @return the current logger level;
+     */
+    public static Level getLevel() {
+        return appLogger.getLevel();
+    }
+
+    /**
+     * Change the log level of this logger.
+     *
+     * @param newLevel the level of log to show
+     */
+    public static void setLevel(Level newLevel) {
+        appLogger.setLevel(newLevel);
+    }
+
+    /**
+     * Load a config file for the logger and set locale to english.
+     *
+     * @param relativePath the path in resources of the config file
+     */
+    public static void init(String relativePath) {
+        init(relativePath, Level.INFO);
+    }
+
+    /**
+     * Load a config file for the logger and set locale to english.
+     *
+     * @param relativePath the path in resources of the config file
+     * @param level        the level to set the logger to
+     */
+    public static void init(String relativePath, Level level) {
+        Locale.setDefault(Locale.ENGLISH);
+        loadConfigFromFile(relativePath);
+        Logger.setLevel(level);
+        Logger.initialized = true;
+    }
+
+    /**
+     * Load a config file for the logger.
+     *
+     * @param relativePath the path in resources of the config file
+     */
+    private static void loadConfigFromFile(String relativePath) {
+        try {
+            InputStream is = Logger.class.getClassLoader().getResourceAsStream(relativePath);
+            if (is == null) {
+                Logger.log(Level.SEVERE, "Logger config file not found at path {0}", relativePath);
+                return;
+            }
+            LogManager.getLogManager().readConfiguration(is);
+            appLogger = java.util.logging.Logger.getLogger(APP_NAME);
+        } catch (IOException e) {
+            Logger.log(e);
+        }
+    }
+
+    /**
+     * Log an exception.
+     *
+     * @param e the exception to log
+     */
+    public static void log(Exception e) {
+        Logger.log(Logger.DEFAULT_DEPTH, Level.SEVERE, e.toString(), e);
+    }
+
+    /**
+     * Log an exception.
+     *
+     * @param lvl the level of logging
+     * @param e   the exception to log
+     */
+    public static void log(Level lvl, Exception e) {
+        Logger.log(Logger.DEFAULT_DEPTH, lvl, e.toString(), e);
+    }
+
+    /**
+     * Log an exception.
+     *
+     * @param e   the exception to log
+     * @param msg the exception msg
+     */
+    public static void log(Exception e, String msg) {
+        Logger.log(Logger.DEFAULT_DEPTH, Level.SEVERE, msg + " : {0}", e);
+    }
+
+    /**
+     * Log an exception.
+     *
+     * @param lvl the level of logging
+     * @param e   the exception to log
+     * @param msg the exception msg
+     */
+    public static void log(Level lvl, Exception e, String msg) {
+        Logger.log(Logger.DEFAULT_DEPTH, lvl, msg + " : {0}", e);
+    }
+
+    /**
+     * Log an INFO message.
+     *
+     * @param message the message
+     * @param objects the object for the message formatting
+     */
+    public static void log(String message, Object... objects) {
+        Logger.log(Logger.DEFAULT_DEPTH, Level.INFO, message, objects);
+    }
+
+    /**
+     * Log a message.
+     *
+     * @param lvl     the level of logging
+     * @param message the message
+     * @param objects the object for the message formatting
+     */
+    public static void log(Level lvl, String message, Object... objects) {
+        Logger.log(Logger.DEFAULT_DEPTH, lvl, message, objects);
+    }
+
+    /**
+     * Log a message.
+     *
+     * @param depth   the source depth in stack
+     * @param lvl     the level of logging
+     * @param message the message
+     * @param objects the object for the message formatting
+     */
+    private static void log(int depth, Level lvl, String message, Object... objects) {
+        if(!initialized) {
+            Logger.log(Level.WARNING, "Logger was not initialized please do so before using.");
+            initialized = true;
+        }
+        message = String.format("[%s-%s] %s", APP_NAME, Utils.getCallingClassName(depth), message);
+        appLogger.log(lvl, message, objects);
+        if (lvl == Level.SEVERE && objects.length > 0 && objects[0] instanceof Exception) {
+            boolean inPackage = false;
+            for (StackTraceElement ste : ((Exception) objects[0]).getStackTrace()) {
+                Logger.log(depth + 1, Level.SEVERE, "\t {0}", ste);
+                if(Logger.BASE_PACKAGE != null){
+                    if (!inPackage && ste.getClassName().startsWith(Logger.BASE_PACKAGE))
+                        inPackage = true;
+                    else if (inPackage && !ste.getClassName().startsWith(Logger.BASE_PACKAGE))
+                        break;
+                }
+            }
+        }
+    }
+}

src/main/java/fr/klemek/logger/Utils.java

@@ -0,0 +1,53 @@
+package fr.klemek.logger;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.MissingResourceException;
+import java.util.ResourceBundle;
+import java.util.logging.Level;
+
+/**
+ * Utility class that store useful misc functions.
+ *
+ * @author Clement Gouin
+ */
+final class Utils {
+
+    private static final ResourceBundle CONFIGURATION_BUNDLE = ResourceBundle.getBundle("logging");
+
+    private Utils() {
+    }
+
+    /*
+     * Configuration utils
+     */
+
+    /**
+     * Get a configuration string by its key.
+     *
+     * @param key the key in the config file
+     * @param defaultValue the default value to use if not found
+     * @return the string or default value if not found
+     */
+    static String getString(String key, String defaultValue) {
+        try {
+            return CONFIGURATION_BUNDLE.getString(key);
+        } catch (MissingResourceException e) {
+            return defaultValue;
+        }
+    }
+
+    /**
+     * Return the class name from the calling class in th stack trace.
+     *
+     * @param stackLevel the level in the stack trace
+     * @return the classname of th calling class
+     */
+    static String getCallingClassName(int stackLevel) {
+        StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
+        if (stackLevel >= stackTrace.length)
+            return null;
+        String[] source = stackTrace[stackLevel].getClassName().split("\\.");
+        return source[source.length - 1];
+    }
+}

src/test/resources/logging.properties

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+#Parameters for good behavior
+handlers=java.util.logging.ConsoleHandler
+.level=WARNING
+java.util.logging.ConsoleHandler.formatter=java.util.logging.SimpleFormatter
+
+#Customize date/time shown with this line
+java.util.logging.SimpleFormatter.format=[%1$tF %1$tT][%4$s]%5$s %n
+
+#Specify your app name here
+app_name=Test
+#(Optional, specify your app package)
+default_package=fr.klemek.logger