Fix Code smells

core/src/main/java/de/jplag/reporting/jsonfactory/ComparisonReportWriter.java

@@ -24,12 +24,12 @@
  */
 public class ComparisonReportWriter {
 
-    private final FileWriter fileWriter;
+    private final FileWriter<Object> fileWriter;
     private final Function<Submission, String> submissionToIdFunction;
     private final Map<String, Map<String, String>> submissionIdToComparisonFileName = new ConcurrentHashMap<>();
     private final Map<String, AtomicInteger> fileNameCollisions = new ConcurrentHashMap<>();
 
-    public ComparisonReportWriter(Function<Submission, String> submissionToIdFunction, FileWriter fileWriter) {
+    public ComparisonReportWriter(Function<Submission, String> submissionToIdFunction, FileWriter<Object> fileWriter) {
         this.submissionToIdFunction = submissionToIdFunction;
         this.fileWriter = fileWriter;
     }

core/src/main/java/de/jplag/reporting/reportobject/writer/DummyWriter.java

@@ -5,9 +5,10 @@
 
 public class DummyWriter implements FileWriter<Object> {
     private static final Logger logger = LoggerFactory.getLogger(DummyWriter.class);
+    private static final String MESSAGE = "DummyWriter writes object {} to path {} with name {} as JSON.";
 
     @Override
     public void writeFile(Object fileToSave, String folderPath, String fileName) {
-        logger.info("DummyWriter writes object " + fileToSave + " to path " + folderPath + " with name " + fileName + " as JSON.");
+        logger.info(MESSAGE, fileToSave, folderPath, fileName);
     }
 }

core/src/test/java/de/jplag/reporting/reportobject/mapper/ComparisonReportWriterTest.java

@@ -14,7 +14,7 @@
 import de.jplag.reporting.reportobject.writer.FileWriter;
 
 public class ComparisonReportWriterTest extends TestBase {
-    private final FileWriter fileWriter = new DummyWriter();
+    private final FileWriter<Object> fileWriter = new DummyWriter();
 
     @Test
     public void firsLevelOfLookupMapComplete() throws ExitException {