Java.lang.NumberFormatException: For input string

class file{
    public static String read(String fileName) throws FileNotFoundException {
        StringBuilder sb = new StringBuilder();
        exists(fileName);
 
        try {
 
            BufferedReader in = new BufferedReader(new FileReader( fileName));
            try {
 
                String s;
                while ((s = in.readLine()) != null) {
                    sb.append(s);
                    sb.append("\n");
                }
            } finally {
 
                in.close();
            }
        } catch(IOException e) {
            throw new RuntimeException(e);
        }
 
 
        return sb.toString();
    }
 
    private static void exists(String fileName) throws FileNotFoundException {
        File file = new File(fileName);
        if (!file.exists()){
            throw new FileNotFoundException(file.getName());
        }
    }
}
 
class wind extends JComponent{
 
     wind(String textFromFile){
 
         String[] stringNumbers = ja.getText().split("  ");
         Double[] numbers = new Double[stringNumbers.length];
         for (int i = 0; i < stringNumbers.length; i++ ) {
             numbers[i] = Double.parseDouble(stringNumbers[i].trim());
         }
    }
}

String[] stringNumbers = ja.getText().trim().split("\\s+");
Double[] numbers = new Double[stringNumbers.length];
for (int i = 0; i < stringNumbers.length; i++ ) {
numbers[i] = Double.parseDouble(stringNumbers[i]);