A debug event queue that automatically registers all WARN and ERROR log messages

so the user does not have to check floodlight logs for them.

src/main/java/net/floodlightcontroller/debugevent/DebugEvent.java

@@ -513,6 +513,7 @@ public class DebugEvent implements IFloodlightModule, IDebugEventService {
         IRestApiService restService =
                 context.getServiceImpl(IRestApiService.class);
         restService.addRestletRoutable(new DebugEventRoutable());
+        DebugEventAppender.setDebugEventServiceImpl(this);
     }
 
 }

src/main/java/net/floodlightcontroller/debugevent/DebugEventAppender.java

+package net.floodlightcontroller.debugevent;
+
+import net.floodlightcontroller.debugevent.IDebugEventService.EventColumn;
+import net.floodlightcontroller.debugevent.IDebugEventService.EventFieldType;
+import net.floodlightcontroller.debugevent.IDebugEventService.EventType;
+import net.floodlightcontroller.debugevent.IDebugEventService.MaxEventsRegistered;
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.UnsynchronizedAppenderBase;
+
+public class DebugEventAppender<E> extends UnsynchronizedAppenderBase<E> {
+    static IDebugEventService debugEvent;
+    static IEventUpdater<WarnErrorEvent> evWarnError;
+    static Thread debugEventRegistryTask = new Thread() {
+        @Override
+        public void run() {
+            while(DebugEventAppender.debugEvent == null) {
+                try {
+                    Thread.sleep(100);
+                } catch (InterruptedException e) {
+                    return;
+                }
+            }
+            //safe to register debugEvent
+            registerDebugEventQueue();
+        }
+    };
+
+    @Override
+    public void start() {
+        DebugEventAppender.debugEventRegistryTask.start();
+        super.start();
+    }
+
+    public static void setDebugEventServiceImpl(IDebugEventService debugEvent) {
+        DebugEventAppender.debugEvent = debugEvent;
+        // It is now ok to register an event Q - but letting this thread go
+        // since it was called from a startUp() routine
+    }
+
+    /**
+     * The logging system calls append for every log message. This method filters
+     * out the WARN and ERROR message and adds to a debug event queue that can
+     * be accessed via cli or rest-api or gui.
+     */
+    @Override
+    protected void append(E eventObject) {
+        if (!isStarted()) {
+            System.out.println("returning wihout doing anything");
+            return;
+        }
+        if (evWarnError != null) {
+            ILoggingEvent ev = ((ILoggingEvent) eventObject);
+            if (ev.getLevel().equals(Level.ERROR) || ev.getLevel().equals(Level.WARN)) {
+                evWarnError.updateEventWithFlush(
+                      new WarnErrorEvent(ev.getFormattedMessage(), ev.getLevel(),
+                                         ev.getThreadName(), ev.getLoggerName()));
+            }
+        }
+    }
+
+    private static void registerDebugEventQueue() {
+        try {
+            evWarnError = debugEvent.registerEvent("net.floodlightcontroller.core",
+                                     "warn-error-queue",
+                                     "all WARN and ERROR logs",
+                                     EventType.ALWAYS_LOG, WarnErrorEvent.class,
+                                     100);
+        } catch (MaxEventsRegistered e) {
+            e.printStackTrace();
+        }
+
+    }
+
+    public static class WarnErrorEvent {
+        @EventColumn(name = "message", description = EventFieldType.STRING)
+        String message;
+
+        @EventColumn(name = "level", description = EventFieldType.OBJECT)
+        Level level;
+
+        @EventColumn(name = "threadName", description = EventFieldType.STRING)
+        String threadName;
+
+        @EventColumn(name = "logger", description = EventFieldType.OBJECT)
+        String logger;
+
+        public WarnErrorEvent(String message, Level level, String threadName,
+                              String logger) {
+            this.message = message;
+            this.level = level;
+            this.threadName = threadName;
+            this.logger = logger;
+        }
+    }
+
+}