JAVA編程：有五個學生，每一個學生有3門課（語文、數學、英語）的成績，

 1 import java.io.FileReader;  2 import java.io.FileWriter;  3 import java.io.IOException;  4 import java.util.Collections;  5 import java.util.Comparator;  6 import java.util.LinkedList;  7 import java.util.Scanner;  8  
 9 public class Student  10 {  11     double chinese;  12     double math;  13     double english;  14     double sum;  15  String sname;  16  
 17     public Student ( double chinese, double math, double english, double sum, String sname )  18  {  19         this.chinese = chinese;  20         this.math = math;  21         this.english = english;  22         this.sum = sum;  23         this.sname = sname;  24  }  25  
 26  @Override  27     public String toString ()  28  {  29         return String.format ("%s\t\t%2$.1f\t\t\t%3$.1f\t\t\t%4$.1f\t\t\t%5$.1f", sname, chinese, math, english, sum);  30  }  31  
 32     public static void main ( String[] args )  33  {  34         Scanner scanner = new Scanner (System.in);  35         LinkedList<Student> list = new LinkedList<Student> ();  36         System.out.println ("從鍵盤輸入學生的信息，輸入格式爲：name,30,30,30（姓名，<a href="https://www.baidu.com/s?wd=%E4%B8%89%E9%97%A8&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1YvuhnkuWN-njmvnyPBPWnv0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6K1TL0qnfK1TL0z5HD0IgF_5y9YIZ0lQzqlpA-bmyt8mh7GuZR8mvqVQL7dugPYpyq8Q1DLPWT3PWR3rjRLPjfdrHRvP0" target="_blank" class="baidu-highlight">三門</a>課成績）<直接回車結束>");
 37         while (scanner.hasNextLine ())  38  {  39             String line = scanner.nextLine ().trim ();  40             if ("".equals (line))  41  {  42                 break;  43  }  44             String[] info = line.split ("\\,");  45             String name = info[0];  46             double chinese = 0;  47             double math = 0;  48             double english = 0;  49             double sum = 0;  50             try
 51  {  52                 chinese = Double.parseDouble (info[1]);  53                 math = Double.parseDouble (info[2]);  54                 english = Double.parseDouble (info[3]);  55                 sum = chinese + math + english;  56  }  57             catch (Exception e)  58  {  59                 System.out.println ("格式不正確，重寫輸入：");  60                 continue;  61  }  62             Student student = new Student (chinese, math, english, sum, name);  63  list.add (student);  64  }  65  scanner.close ();  66         Collections.sort (list, new Comparator<Student> ()  67  {  68  @Override  69             public int compare ( Student o1, Student o2 )  70  {  71                 if (o1.sum > o2.sum)  72  {  73                     return -1;  74  }  75                 else if (o1.sum < o2.sum)  76  {  77                     return 1;  78  }  79                 else
 80  {  81                     return 0;  82  }  83  }  84  });  85         try
 86  {  87             String file = "stu.txt";  88             String line = System.getProperty ("line.separator");  89             FileWriter fw = new FileWriter (file, true);  90             FileReader fr = new FileReader (file);  91             if (fr.read () == -1)  92  {  93                 fw.write ("姓名\t\t語文\t\t數學\t\t<a href="https://www.baidu.com/s?wd=%E8%8B%B1%E8%AF%AD&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1YvuhnkuWN-njmvnyPBPWnv0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6K1TL0qnfK1TL0z5HD0IgF_5y9YIZ0lQzqlpA-bmyt8mh7GuZR8mvqVQL7dugPYpyq8Q1DLPWT3PWR3rjRLPjfdrHRvP0" target="_blank" class="baidu-highlight">英語</a>\t\t總分" + line);
 94  }  95  fr.close ();  96             for ( Student student : list )  97  {  98                 fw.write (student.toString () + line);  99  fw.flush (); 100  } 101  fw.close (); 102             System.out.println ("加入完畢."); 103  } 104         catch (IOException e) 105  {} 106  } 107 }