Issue-1160 Code clean up, send to client only error type without whole error message

Author: Oleg Aleksandrov

src/main/java/org/java_websocket/WebSocketImpl.java

@@ -26,8 +26,6 @@
 package org.java_websocket;
 
 import java.io.IOException;
-import java.io.PrintWriter;
-import java.io.StringWriter;
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
 import java.nio.channels.ByteChannel;
@@ -419,7 +417,8 @@ private void decodeFrames(ByteBuffer socketBuffer) {
       log.error("Closing web socket due to an error during frame processing");
       Exception exception = new Exception(e);
       wsl.onWebsocketError(this, exception);
-      close(CloseFrame.UNEXPECTED_CONDITION, exception.getMessage());
+      String errorMessage = "Got error " + e.getClass().getName() + " on the server side";
+      close(CloseFrame.UNEXPECTED_CONDITION, errorMessage);
     }
   }
 

src/main/java/org/java_websocket/server/WebSocketServer.java

@@ -1083,7 +1083,7 @@ public void run() {
         if (ws != null) {
           ws.close();
         }
-        log.error("Got fatal error in worker thread" + getName());
+        log.error("Got fatal error in worker thread {}", getName());
         Exception exception = new Exception(e);
         handleFatal(ws, exception);
       } catch (Throwable e) {