code: private void enterAppName(BufferedReader br) throws IOException {
          while (true) {
              printInstruction("Enter your application name: [" + getDefaultAppName() + "]");
  
              String appNameCandidate = br.readLine();
              if (isBlank(appNameCandidate)) {
                  appName = getDefaultAppName();
                  break;
              } else {
                  if (isPackageNameValid(getDefaultRootPackage() + "." + appNameCandidate)) {
                      appName = appNameCandidate;
                      break;
                  } else {
                      System.out.println("Oops! invalid application name. Keep it simple, no '-', etc...");
                      System.out.println("");
                      continue;
                  }
              }
          }
      }
docs: Ask the user to enter the application name.