3 files changed, 165 insertions, 0 deletions
diff --git a/graphs/java/singleton/src/main/java/fr/epita/assistants/logger/Logger.java b/graphs/java/singleton/src/main/java/fr/epita/assistants/logger/Logger.java
new file mode 100644
index 0000000..4cc59f8
--- /dev/null
+++ b/graphs/java/singleton/src/main/java/fr/epita/assistants/logger/Logger.java
@@ -0,0 +1,62 @@
+package fr.epita.assistants.logger;
+
+/**
+ * A standard logger interface
+ */
+public interface Logger {
+    /**
+     * The Level enum, representing the gravity of a log message.
+     */
+    enum Level {
+        INFO,
+        WARN,
+        ERROR
+    }
+
+    /**
+     * Formats a message and returns it as a string
+     * @param level   The gravity level of the logged message.
+     * @param message The logged message.
+     * @return
+     */
+    static String getFormattedLog(final Level level, final String message) {
+        return '[' +
+                level.toString() +
+                "] " +
+                message;
+    }
+
+    /**
+     * Outputs the logged message with the format '[LEVEL] Message' to stderr.
+     *
+     * @param level   The gravity level of the logged message.
+     * @param message The logged message.
+     */
+    void log(final Level level, final String message);
+
+    /**
+     * Getter for infoCounter.
+     *
+     * @return infoCounter.
+     */
+    int getInfoCounter();
+
+    /**
+     * Getter for warnCounter.
+     *
+     * @return warnCounter.
+     */
+    int getWarnCounter();
+
+    /**
+     * Getter for errorCounter.
+     *
+     * @return errorCounter.
+     */
+    int getErrorCounter();
+
+    /**
+     * Resets the counters.
+     */
+    void reset();
+}
diff --git a/graphs/java/singleton/src/main/java/fr/epita/assistants/singleton/SingletonEnumLogger.java b/graphs/java/singleton/src/main/java/fr/epita/assistants/singleton/SingletonEnumLogger.java
new file mode 100644
index 0000000..4fb969e
--- /dev/null
+++ b/graphs/java/singleton/src/main/java/fr/epita/assistants/singleton/SingletonEnumLogger.java
@@ -0,0 +1,49 @@
+package fr.epita.assistants.singleton;
+
+import fr.epita.assistants.logger.Logger;
+
+public enum SingletonEnumLogger implements Logger {
+    INSTANCE;
+    int infoCounter;
+    int errorCounter;
+    int warnCounter;
+
+    @Override
+    public void log(Level level, String message) {
+        switch (level)
+        {
+            case INFO:
+                infoCounter++;
+                break;
+            case WARN:
+                warnCounter++;
+                break;
+            case ERROR:
+                errorCounter++;
+                break;
+        }
+        System.err.println(Logger.getFormattedLog(level, message));
+    }
+
+    @Override
+    public int getInfoCounter() {
+        return infoCounter;
+    }
+
+    @Override
+    public int getWarnCounter() {
+        return warnCounter;
+    }
+
+    @Override
+    public int getErrorCounter() {
+        return errorCounter;
+    }
+
+    @Override
+    public void reset() {
+        infoCounter = 0;
+        warnCounter = 0;
+        errorCounter = 0;
+    }
+}
diff --git a/graphs/java/singleton/src/main/java/fr/epita/assistants/singleton/StaticSingletonLogger.java b/graphs/java/singleton/src/main/java/fr/epita/assistants/singleton/StaticSingletonLogger.java
new file mode 100644
index 0000000..51d1801
--- /dev/null
+++ b/graphs/java/singleton/src/main/java/fr/epita/assistants/singleton/StaticSingletonLogger.java
@@ -0,0 +1,54 @@
+package fr.epita.assistants.singleton;
+
+import fr.epita.assistants.logger.Logger;
+
+public class StaticSingletonLogger implements Logger {
+    int infoCounter;
+    int errorCounter;
+    int warnCounter;
+    private StaticSingletonLogger() {
+        infoCounter = 0;
+        errorCounter = 0;
+        warnCounter = 0;
+    }
+
+    private static class InstanceHolder {
+        private static final StaticSingletonLogger _INSTANCE = new StaticSingletonLogger();
+    }
+
+    public static StaticSingletonLogger getInstance() {
+        return InstanceHolder._INSTANCE;
+    }
+    @Override
+    public void log(Level level, String message) {
+        switch (level)
+        {
+            case INFO -> infoCounter++;
+            case WARN -> warnCounter++;
+            case ERROR -> errorCounter++;
+        }
+        System.err.println(Logger.getFormattedLog(level, message));
+    }
+
+    @Override
+    public int getInfoCounter() {
+        return infoCounter;
+    }
+
+    @Override
+    public int getWarnCounter() {
+        return warnCounter;
+    }
+
+    @Override
+    public int getErrorCounter() {
+        return errorCounter;
+    }
+
+    @Override
+    public void reset() {
+        infoCounter = 0;
+        warnCounter = 0;
+        errorCounter = 0;
+    }
+}