Suggested fix for #52

.gitignore

@@ -6,3 +6,5 @@ bin/
 
 # Maven
 target/
+
+.idea/

src/main/java/com/github/markusbernhardt/proxy/util/Logger.java

@@ -1,10 +1,5 @@
 package com.github.markusbernhardt.proxy.util;
 
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-
-import org.slf4j.LoggerFactory;
-
 /*****************************************************************************
  * Simple logging support for the framework. You need to add a logging listener
  * that needs to send the logging events to a backend.
@@ -42,60 +37,6 @@ public interface LogBackEnd {
 
   }
 
-  /*****************************************************************************
-   * Slf4j logging backend.
-   ****************************************************************************/
-
-  public class Slf4jLogBackEnd implements LogBackEnd {
-
-    protected Map<Class<?>, org.slf4j.Logger> loggers = new ConcurrentHashMap<Class<?>, org.slf4j.Logger>();
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public void log(Class<?> clazz, LogLevel loglevel, String msg, Object... params) {
-      org.slf4j.Logger log = getLogger(clazz);
-
-      switch (loglevel) {
-      case ERROR:
-        if (log.isErrorEnabled()) {
-          log.error(msg, params);
-        }
-        break;
-      case WARNING:
-        if (log.isWarnEnabled()) {
-          log.warn(msg, params);
-        }
-        break;
-      case INFO:
-        if (log.isInfoEnabled()) {
-          log.info(msg, params);
-        }
-        break;
-      case TRACE:
-        if (log.isTraceEnabled()) {
-          log.trace(msg, params);
-        }
-        break;
-      case DEBUG:
-        if (log.isDebugEnabled()) {
-          log.debug(msg, params);
-        }
-        break;
-      }
-    }
-
-    protected org.slf4j.Logger getLogger(Class<?> clazz) {
-      org.slf4j.Logger logger = loggers.get(clazz);
-      if (logger == null) {
-        logger = LoggerFactory.getLogger(clazz);
-        loggers.put(clazz, logger);
-      }
-      return logger;
-    }
-  }
-
   private static LogBackEnd backend;
 
   /*************************************************************************
@@ -133,9 +74,10 @@ public static void setBackend(LogBackEnd backend) {
    ************************************************************************/
 
   public static void log(Class<?> clazz, LogLevel loglevel, String msg, Object... params) {
-    if (backend != null) {
-      backend.log(clazz, loglevel, msg, params);
+    if (backend == null) {
+      backend = new Slf4jLogBackEnd();
     }
+    backend.log(clazz, loglevel, msg, params);
   }
 
 }

src/main/java/com/github/markusbernhardt/proxy/util/Slf4jLogBackEnd.java

@@ -0,0 +1,60 @@
+package com.github.markusbernhardt.proxy.util;
+
+import org.slf4j.LoggerFactory;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/*****************************************************************************
+ * Slf4j logging backend.
+ ****************************************************************************/
+
+public class Slf4jLogBackEnd implements Logger.LogBackEnd {
+
+  protected Map<Class<?>, org.slf4j.Logger> loggers = new ConcurrentHashMap<Class<?>, org.slf4j.Logger>();
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public void log(Class<?> clazz, Logger.LogLevel loglevel, String msg, Object... params) {
+    org.slf4j.Logger log = getLogger(clazz);
+
+    switch (loglevel) {
+    case ERROR:
+      if (log.isErrorEnabled()) {
+        log.error(msg, params);
+      }
+      break;
+    case WARNING:
+      if (log.isWarnEnabled()) {
+        log.warn(msg, params);
+      }
+      break;
+    case INFO:
+      if (log.isInfoEnabled()) {
+        log.info(msg, params);
+      }
+      break;
+    case TRACE:
+      if (log.isTraceEnabled()) {
+        log.trace(msg, params);
+      }
+      break;
+    case DEBUG:
+      if (log.isDebugEnabled()) {
+        log.debug(msg, params);
+      }
+      break;
+    }
+  }
+
+  protected org.slf4j.Logger getLogger(Class<?> clazz) {
+    org.slf4j.Logger logger = loggers.get(clazz);
+    if (logger == null) {
+      logger = LoggerFactory.getLogger(clazz);
+      loggers.put(clazz, logger);
+    }
+    return logger;
+  }
+}