student.java

学籍管理

     import java.io.*;
      class Stu{
	     String name;
	     String number;
	     static int stunum=0;
	   }
     
      class W{
          void input(Stu st[])
	       throws IOException
	      {
	      int k=0 ;
     	  String str ;
	      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	      System.out.print("输入你要录入的学生人数:");
		  str=br.readLine();
     	  try{
     	   k = Integer.parseInt(str);
     	  }
     	  catch(NumberFormatException exc){
     	   System.out.println("Invalibd ");
          } 
     	  for(int j=0;j<k;j++){
     	   System.out.println("输入姓名和学号");
           st[j+Stu.stunum].name=br.readLine(); 
	       st[j+Stu.stunum].number = br.readLine();
	      }
	      Stu.stunum+=k;
	       
	     }  
       
         void put(Stu stu[]){
         	for(int i=0;i<Stu.stunum;i++)
            System.out.println(stu[i].name +"\t"+stu[i].number);
         }
         
        int search(Stu stu[]){
     	String number="";
     	int i=0;
          	             
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.print("输入寻找学号:");
        try{  
         number = br.readLine();            
	    }catch(IOException e){} 
	    for(;i<Stu.stunum;i++){
	    	if(number.compareTo(stu[i].number)==0 )
	    	  {
	    	  	System.out.print(stu[i].name+"\t"+stu[i].number);
	    	  	return i;
	    	  	 
	    	   }
	    }  
	    if(i==Stu.stunum)
	     System.out.println("没有学号为"+number);
	     return -1;     
	 }      
         
       void  change(Stu stu[])
        throws IOException{
       	int num;
       	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       	num = search(stu);
        if(num == -1)
         return ;
        else
         {  
            System.out.println("被改的学生信息为:"+ stu[num].name+"\t"+stu[num].number);
            System.out.println("输入你要修改学生的学号:");
            stu[num].name = br.readLine();
            stu[num].number = br.readLine();
          }
       } 
       	
       	
    	void delete(Stu stu[]){
       	 	int num = -1;
       	    num = search(stu);
       	    if (num == -1)
       	    	return ;
       	    else{
       	   	for(int i=num; i<Stu.stunum; i++){
       	   		stu[i]=stu[i+1];
       	   	}
       	   } 
       	   	 	
       	}           
       char menu()
       throws IOException{
       	  	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
         	char ch='6';
         	do{
         		System.out.println("\n学籍管理系统");
         		System.out.println("1:输入记录");
         		System.out.println("2:输出记录");
         		System.out.println("3:查找记录");
         		System.out.println("4:修改记录");
         		System.out.println("5:删除记录");
         		System.out.println("0:退出");
         	    System.out.print("输入选择 ");
         	    try{
         	    	ch =(char)br.read();
         	    }catch(IOException e){}
         	 }while(ch>'5'||ch<'0');
           return ch;	 
          }
    } 
      
      
       class Student
        {
           public static void main(String args[])
           throws IOException{
           	 W w= new W();
           	 char ch='6';
             Stu stu[] = new Stu[5];
             for(int i=0;i<5; i++)
               stu[i]  = new Stu();
            do{
           	   ch=w.menu();   
             switch(ch){
              case '1':w.input(stu);
           	           break;
              case '2':w.put(stu);
                       break;
              case '3':w.search(stu);
                       break;
              case '4':w.change(stu);
                       break;   
              case '5':w.delete(stu);
                       break;  	      
              default:
             }
           }while(ch!='0');
         }
       }