diff -r f7433671fec5 -r 1c62c6009161 src/main/java/de/uapcore/sudoku/DocumentHandler.java
--- a/src/main/java/de/uapcore/sudoku/DocumentHandler.java	Sat Jul 25 15:56:48 2020 +0200
+++ b/src/main/java/de/uapcore/sudoku/DocumentHandler.java	Mon Jul 27 10:56:17 2020 +0200
@@ -59,13 +59,13 @@
                 }
                 Matcher m = pat.matcher(line);
                 if (m.matches()) {
-                    String c[] = line.trim().split(" ");
+                    String[] c = line.trim().split(" ");
                     if (c.length != 9) {
                         break;
                     }
                     for (int i = 0 ; i < 9 ; i++) {
                         field.setCellValue(i, row,
-                                c[i].equals("_") ? 0 : Integer.valueOf(c[i]));
+                                c[i].equals("_") ? 0 : Integer.parseInt(c[i]));
                     }
                     row++;
                 } else {