Add log statistic for verifier

dmnverifierapi/src/main/java/de/unikoblenz/fgbks/core/dmn/verification/verifier/AbstractVerifier.java

@@ -12,9 +12,14 @@ import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Future;
 import org.apache.commons.lang3.Validate;
+import org.apache.commons.lang3.time.StopWatch;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public abstract class AbstractVerifier implements Verifier {
 
+  protected final Logger LOGGER = LoggerFactory.getLogger(getClass().getSimpleName());
+
   protected VerificationType verificationType;
   protected AbstractDmnVerifierConfig verifierConfig;
   protected VerifierResult.Builder resultBuilder;
@@ -55,9 +60,18 @@ public abstract class AbstractVerifier implements Verifier {
   }
 
   private VerifierResult verify() {
-    System.out.println("start " + this.getClass().getSimpleName());
+    LOGGER.info("Starting verification " + getVerificationType().getName());
+    StopWatch watch = new StopWatch();
+    watch.start();
     doVerification();
-    System.out.println("end " + this.getClass().getSimpleName());
+    watch.stop();
+    LOGGER.info(
+        "Verification "
+            + getVerificationType().getName()
+            + " finished. "
+            + "Time Elapsed: "
+            + watch.getTime()
+            + " ms");
     return resultBuilder.build();
   }