Change log level on debug for child app in different package

src/main/java/com/bakdata/common_kafka_streams/KafkaStreamsApplication.java

@@ -76,6 +76,13 @@ private static String[] addEnvironmentVariablesArguments(final String[] args) {
         return allArgs.toArray(String[]::new);
     }
 
+    /**
+     * This variable is usually set on application start. When the application is running in debug mode it is used to
+     * reconfigure the child app package logger. On default it points to the package of this class allowing to execute
+     * the run method independently.
+     */
+    private static String appPackageName = KafkaStreamsApplication.class.getPackageName();
+
     /**
      * <p>This methods needs to be called in the executable custom application class inheriting from
      * {@link KafkaStreamsApplication}.</p>
@@ -84,14 +91,16 @@ private static String[] addEnvironmentVariablesArguments(final String[] args) {
      * @param args Arguments passed in by the custom application class.
      */
     protected static void startApplication(final KafkaStreamsApplication app, final String[] args) {
+        appPackageName = app.getClass().getPackageName();
         final String[] populatedArgs = addEnvironmentVariablesArguments(args);
         CommandLine.run(app, System.out, populatedArgs);
     }
 
     @Override
     public void run() {
-        if(this.debug) {
+        if (this.debug) {
             org.apache.log4j.Logger.getLogger("com.bakdata").setLevel(Level.DEBUG);
+            org.apache.log4j.Logger.getLogger(appPackageName).setLevel(Level.DEBUG);
         }
         log.debug(this.toString());
         final var kafkaProperties = this.getKafkaProperties();

src/test/java/com/bakdata/common_kafka_streams/test_applications/WordCount.java

@@ -52,7 +52,11 @@ public class WordCount extends KafkaStreamsApplication {
 
     @CommandLine.Option(names = "--output-topic", required = true)
     private String outputTopic = "";
-
+
+    public static void main(final String[] args) {
+        startApplication(new WordCount(), args);
+    }
+
     @Override
     public void buildTopology(final StreamsBuilder builder) {
         final Serde<String> stringSerde = Serdes.String();