使用类格式化程序将数据写入顺序文本文件。

import java.io.FileNotFoundException;
/**来自 
 时   代     Java  公  众  号 - nowjava.com**/

import java.util.Formatter;

import java.util.FormatterClosedException;

import java.util.NoSuchElementException;

import java.util.Scanner;


public class Main {

  private static Formatter output; // outputs text to a file


  public static void main(String[] args) {

    openFile();

    addRecords();/**来 自 n  o  w  j  a  v  a . c o m**/

    closeFile();

  }


  // open file clients.txt

  public static void openFile() {

    try {

      output = new Formatter("clients.txt"); // open the file

    } catch (SecurityException securityException) {

      System.err.println("Write permission denied. Terminating.");

      System.exit(1); // terminate the program

    } catch (FileNotFoundException fileNotFoundException) {

      System.err.println("Error opening file. Terminating.");

      System.exit(1); // terminate the program

    }

  }


  // add records to file

  public static void addRecords() {

    Scanner input = new Scanner(System.in);

    System.out.printf("%s%n%s%n? ",

        "Enter account number, first name, last name and balance.",

        "Enter end-of-file indicator to end input.");


    while (input.hasNext()) // loop until end-of-file indicator

    {

      try {

        // output new record to file; assumes valid input

        output.format("%d %s %s %.2f%n", input.nextInt(), input.next(),

            input.next(), input.nextDouble());

      } catch (FormatterClosedException formatterClosedException) {

        System.err.println("Error writing to file. Terminating.");

        break;

      } catch (NoSuchElementException eleme