我试着读取一个文件，只打印每行的第一个数字。我尝试过使用split，但它从来没有返回正确的结果，它只是在下表中打印整个内容。任何帮助都将不胜感激

**thats my file**

 40    3  Trottmann
 43    3  Brubpacher
252    3  Stalder
255    3  Leuch
258    3  Zeller
261    3  Reolon
264    3  Ehrismann
267    3  Wipf
270    3  Widmer 

**expected output**

 40
 43
258
261
264
267
270

输出

258
261
264
267
270

公共类词{

public static void main(String[] args) {

                // Create file
                File file = new File("/Users/lobsang/documents/start.txt");

                try {
                    // Create a buffered reader
                    // to read each line from a file.
                    BufferedReader in = new BufferedReader(new FileReader(file));
                    String s;

                    // Read each line from the file and echo it to the screen.
                    s = in.readLine();
                    while (s != null) {

                        System.out.println(s.split("\s")[0]);

                        s = in.readLine();
                    }

                    // Close the buffered reader
                    in.close();

                } catch (FileNotFoundException e1) {
                    // If this file does not exist
                    System.err.println("File not found: " + file);

                } catch (IOException e2) {
                    // Catch any other IO exceptions.
                    e2.printStackTrace();
                }
            }

        }