简单学生成绩管理系统（Java实现）

package stu_sys;

import java.lang.*; import java.io.*; import aprin.stu_sys.*;

public class Main {   public static void main(String[] args)   {     while(true)     {       Menu.paint();       int ctrlTag = Console.readInt();       switch(ctrlTag)       {         case 1:         {           Menu.action1();           break;         }

        case 2:         {           Menu.action2();           break;         }

        case 3:         {           Menu.action3();           break;         }

        case 4:         {           Menu.action4();           break;         }

        case 5:         {           Menu.action5();           break;         }

        case 6:         {           Menu.action6();           break;         }

        case 0:         {           System.exit(0);           break;         }       }     }   } }

class Student {   private int number;   private String name;   private int english;   private int math;   private int computer;   private int average;   private int total;

  public Student()   {   }

  public Student(int number, String name, int english, int math, int computer)   {     this.number = number;     this.name = name;     this.english = english;     this.math = math;     this.computer = computer;     total = english + math + computer;     average = total/3;   }

  public int getNumber()   {     return number;   }

  public String getName()   {     return name;   }

  public int getEnglish()   {     return english;   }

  public int getMath()   {     return math;   }

  public int getComputer()   {     return computer;   }

  public int getAverage()   {     return average;   }

  public int getTotal()   {     return total;   } }

class StudentSet {   private static final int maxLen = 1000;   private static int len = 0;   private static Student[] data = new Student[maxLen];

  public static int getMaxLen()   {     return maxLen;   }

  public static int getLen()   {     return len;   }

  public static Student getData(int index)   {     return data[index];   }

  public static int addData(Student newData)   {     if (len < maxLen)     {       data[len] = newData;       len++;       return 0;     } else     {       return -1;     }   }

  public static void sortData()   {     for (int i = 0; i < len -1; i++)     {       int minIndex = i;       for (int j = i+1; j < len; j++)       {         if (data[minIndex].getAverage() > data[j].getAverage())         {           minIndex = j;         }       }       if (minIndex != i)       {         Student temp = data[i];         data[i] = data[minIndex];         data[minIndex] = temp;       }     }   }

  public static int search(int number)   {     for(int i = 0; i < len; i++)     {       if (data[i].getNumber() == number)       {         return i;       }     }     return -1;   }

  public static int delete(int number)   {     for (int i = 0; i < len; i++)     {       if (data[i].getNumber() == number)       {         for (int j = i + 1; j < len; j++)         {           data[j-1] = data[j];         }         len--;         return 0;       }     }     return -1;   }

  public static int stat(int min, int max)   {     int sum =0;

    for (int i = 0; i < len; i++)     {       if ((data[i].getAverage() >= min) && (data[i].getAverage() <= max))       {         sum++;       }     }     return sum;   } }

class Console {   public static int readInt()   {     int result = 0;     try{       String temp =new BufferedReader(new InputStreamReader(System.in)).readLine();       result = Integer.parseInt(temp);     } catch (Exception e)     {       System.out.println("Error: "+e);     }     return result;   }

  public static String readSting()   {     String result = null;     try{       result = new BufferedReader(new InputStreamReader(System.in)).readLine();     } catch (Exception e)     {       System.out.println("Error: "+e);     }     return result;   } }

class Menu {   public static void paint()   {     clrscr();     for (int i = 0; i < 80; i++)     {       System.out.print('=');     }     System.out.println();

    System.out.println("                             学生成绩管理系统                 ");     System.out.println();     System.out.println("               1 输入记录                       2 输出所有记录");     System.out.println("               3 按平均成绩排序并输出           4 查找记录");     System.out.println("               5 统计各分数段人数               6 删除记录");     System.out.println("               0 退出");

    for (int i = 0; i < 80; i++)     {       System.out.print('=');     }     System.out.println("                                            Copyright (C) 2005 官成文 厦门大学");     System.out.println();     System.out.print("请输入命令：");   }

  public static int action1()   {     while(true)     {       clrscr();       System.out.print("待输入记录的学号（输入“-1”退出）：");

      int number = Console.readInt();       if (number != -1)       {         System.out.print("  *姓名：");         String name = Console.readSting();         System.out.print("  *英语：");         int english = Console.readInt();         System.out.print("  *数学：");         int math = Console.readInt();         System.out.print("  *计算机：");         int computer = Console.readInt();         Student newData = new Student(number, name, english, math, computer);         if (StudentSet.addData(newData) == -1)         {           System.out.println("数据溢出！");           return -2;         }       } else       {         return -1;       }     }   }

  public static void action2()   {     clrscr();     if (StudentSet.getLen() == 0)     {       System.out.println("没有记录！");     } else     {       System.out.println("         数学|英语|计算机|平均|总计");       for (int i = 0; i < StudentSet.getLen(); i++)       {         System.out.println("学号："+StudentSet.getData(i).getNumber()+"  姓名："+StudentSet.getData(i).getName());         System.out.println("      "+StudentSet.getData(i).getMath()+"    "+StudentSet.getData(i).getEnglish()+           "    "+StudentSet.getData(i).getComputer()+"    "+StudentSet.getData(i).getAverage()+"    "+StudentSet.getData(i).getTotal());       }     }   }

  public static void action3()   {     StudentSet.sortData();     action2();   }

  public static void action4()   {     clrscr();     System.out.print("请输入要查找记录的学号：");     int number = Console.readInt();     int i;     if ((i = StudentSet.search(number)) != -1)     {       clrscr();       System.out.println("         数学|英语|计算机|平均|总计");       System.out.println("学号："+StudentSet.getData(i).getNumber()+"  姓名："+StudentSet.getData(i).getName());       System.out.println("      "+StudentSet.getData(i).getMath()+"    "+StudentSet.getData(i).getEnglish()+         "    "+StudentSet.getData(i).getComputer()+"    "+StudentSet.getData(i).getAverage()+"    "+StudentSet.getData(i).getTotal());     } else     {       System.out.println("没有找到相应的记录！");     }   }   public static void action5()   {     clrscr();     System.out.println("90-100: "+StudentSet.stat(90, 100)+"人");     System.out.println("80-89: "+StudentSet.stat(80, 89)+"人");     System.out.println("70-79: "+StudentSet.stat(70, 79)+"人");     System.out.println("60-69: "+StudentSet.stat(60, 69)+"人");     System.out.println("0-59: "+StudentSet.stat(0, 59)+"人");   }

  public static void action6()   {     while(true)     {       clrscr();       System.out.print("请输入要删除记录的学号（输入“-1”退出）：");       int number = Console.readInt();       if (number != -1)       {         if(StudentSet.delete(number) == -1)         {           System.out.println("没有找到相应的记录！");           return;         } else         {           System.out.println("删除记录成功！");         }       } else       {         return;       }     }   }

  public static void clrscr()   { //temp function     System.out.println();     System.out.println();   } }