togglz aspect (#1743)

* togglz aspect

* formatting

* trigger travis build

spring-boot/src/main/java/com/baeldung/toggle/FeaturesAspect.java

@@ -0,0 +1,27 @@
+package com.baeldung.toggle;
+
+import org.apache.log4j.Logger;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.springframework.stereotype.Component;
+
+@Aspect
+@Component
+public class FeaturesAspect {
+
+    private static final Logger LOG = Logger.getLogger(FeaturesAspect.class);
+
+    @Around(value = "@within(featureAssociation) || @annotation(featureAssociation)")
+    public Object checkAspect(ProceedingJoinPoint joinPoint, FeatureAssociation featureAssociation) throws Throwable {
+        if (featureAssociation.value()
+            .isActive()) {
+            return joinPoint.proceed();
+        } else {
+            LOG.info("Feature " + featureAssociation.value()
+                .name() + " is not enabled!");
+            return null;
+        }
+    }
+
+}