stu.java

hao de fggfgf gfdg gfg

import java.io.*;
import java.util.*; 

public class STU
{ 
	static boolean isDelete = true; 
	static boolean isFind = true; 
	public static void main(String [] args)//主方法,程序从这里开始运行 
	throws IOException,NumberNotFoundException 
	{ 
	int choice=-1;	 
	STU lp = new STU(); 
	System.out.println(); 
	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.print("1.增加数据:"+"                    2.查找数据:\n"+ "3.删除数据:"+ "                    4.清除所有数据:\n"+ "5.把数据全部打印到屏幕"+ "         6.把成绩按学号排序\n"+ "7.修改数据"+ 
"                     8.统计已记录成绩学生数\n"+ "9.关于作者"+ "                     0.退出程序.\n"); 
for (int i = 0; i < 80; i++)
    {
      System.out.print('=');
    }
while(true)
{   
    System.out.println();
    System.out.print("请输入命令：");
	BufferedReader in = //从终 
	new BufferedReader( //端接 
	new InputStreamReader(System.in));//收数 
	String inputLine = in.readLine(); //字选 
	choice= Integer.valueOf(inputLine).intValue();//项; 
   if(choice!=0)
   {
	switch(choice) 
	{ 
	case 1: 
		{//1.增加数据 
		String str = lp.inputData(); 
		lp.addData(str); 
							System.out.println("增加数据成功.");  
		break;}
	case 2: 
		{//2.查找数据 
		long find = 0; 
							System.out.print("请输入你要查找的学生学号:"); 
		BufferedReader inn = new 		BufferedReader( new InputStreamReader(System.in)); 
		String inputLi = inn.readLine(); 
		find = Integer.valueOf(inputLi).longValue(); 
		lp.findData(find); 
		break;} 
	case 3: 
		{//3.删除数据 
		long deleteNumber = 0; 
							System.out.print("请输入你想删除的同学的学号:"); 
		BufferedReader bf = new BufferedReader ( new InputStreamReader(System.in)); 
		String inputL = bf.readLine(); 
		deleteNumber = Integer.valueOf(inputL).longValue(); 
		lp.deleteData(deleteNumber); 
		if(isDelete) 
								System.out.println("删除数据成功!"); 
		break;} 
	case 4: 
		{ 
		lp.clearData();//4.清除所有数据  
		break;} 
	case 5: 
		{ 
		print();//5.把数据全部打印到屏幕 
		break;} 
	case 6: 
		{ 
		lp.numSort();//6.把成绩按学号排序 
							System.out.println("按照学号从小到大排序成功!\n"+ "排序后:\n"); 
		print(); 
		break;} 
	case 7: 
		{ 
		lp.rewrite();//7.修改数据 
		break;} 
	case 8: 
		{ 
		int count = lp.count(); 
							System.out.println("共有"+count+"个学生已经记录."); 
		break;} 
	case 9: 
		{ System.out.print( "\t\t；河南工业大学 \n"+"\t\t信息科学与工程学院\n"+ "\t\tQQ:04221\n");  
		break;} 
/*	case 0:
		{System.out.println("GoodBye! ^-^"); 
		System.exit(0); 
		
		}
*/
	} 
  }
  else{System.out.println("GoodBye! ^-^"); 
		System.exit(0); }
}
}

public String inputData()//从终端接收数据的方法,返回字符串 
throws IOException,NumberFormatException 
{  
System.out.print("请依次输入 :学号 姓名 性别 高数 英语 专业\n" + "每项数据请用空格隔开:"); 
String all = ""; 
try{ 
BufferedReader in = //从终 
new BufferedReader ( //端接 
new InputStreamReader(System.in)); //收数 
String inputLine = in.readLine(); //据 
StringTokenizer str = 
new StringTokenizer(inputLine," ");//接收的数据用空格隔开,这个类用来提取每个字符串 
long num = Integer.valueOf(str.nextToken()).longValue();//学号 
String name = (String)str.nextToken(); //姓名 
String sex = (String)str.nextToken(); //性别 
double math = Integer.valueOf(str.nextToken()).doubleValue();//分数
double english = Integer.valueOf(str.nextToken()).doubleValue();//分数
double spe = Integer.valueOf(str.nextToken()).doubleValue();//分数
double toil=math+english+spe;
double avg=(math+english+spe)/3;
all = String.valueOf(num) +" , "+ 
name +" , "+ sex +" , "+ String.valueOf(math)+" , "+ String.valueOf(english)+" , "+ 
String.valueOf(spe)+" , "+ 
String.valueOf(toil)+" , "+ 
String.valueOf(avg);//把所有的数据用" , "隔开然后在连起来放进字符串all 
}catch (IOException e){} 
catch (NumberFormatException e){} 
return all;//返回字符串all 
} 

public void addData(String str)//增加数据的方法 
throws IOException 
{ 
String s1 ="",s2="" ,s3= ""; 
File file = new File("data.txt"); 
if (file.exists())//如果文件data.txt存在 
{ 
try{ 
BufferedReader in = 
new BufferedReader( 
new FileReader("data.txt")); 
while ((s1=in.readLine())!=null) 
s2+=s1+"\n";//把文件中的每行数据全部放进一个字符串s2 
s2+=str+"\n"; //再把s2于形参str相连放进s2 
BufferedReader in2 = //把字符 
new BufferedReader( //串s2也 
new StringReader(s2)); //就是原 
PrintWriter out = //文件+ 
new PrintWriter( //形参str(新输入的一行数据) 
new BufferedWriter( //重新写进data.txt 
new FileWriter("data.txt"))); //覆盖原来的数据 
while ((s3=in2.readLine())!= null) 
{ 
out.println(s3); 
} 
out.close(); 
System.out.println("write data true."); 
}catch (IOException e){} 
}else{ 
System.err.println("File \"data\" Missing!"); 
} 
} 


public void clearData()//清除data.txt的所有数据的方法 
throws IOException 
{ 
File file = new File("data.txt"); 
if(file.exists())//如果文件在 
{ 
try{ 
PrintWriter out = 
new PrintWriter( 
new BufferedWriter( 
new FileWriter(file))); 
out.print("");//在文件data.txt里写进一个空字符,所以清除了原来的内容 
out.close(); //关闭文件 
System.out.println("clear data true!"); 
}catch(IOException e){} 
}else{ 
System.err.println("File \"data\" Missing!"); 
} 
} 


public void deleteData(long deleteNumber)//删除某条数据 
throws IOException,FileNotFoundException 
{ 
isDelete = true; 
try{ 
DataMap mp = new DataMap();//生成一个自己编写的容器 
long j=0; 
String s1="",s2="",s3=""; 
BufferedReader in = 
new BufferedReader( 
new FileReader("data.txt")); 
while ((s1=in.readLine())!=null) 
{ 
j=numberTokenizer(s1); 
mp.put(j,s1); 
} 
try{ 
if(mp.containsKey( String.valueOf(deleteNumber).toString())) 
{ 
mp.remove(deleteNumber); 
}else 
throw new NumberNotFoundException(); 
Collection c = mp.values(); 
Iterator iter = c.iterator(); 
while(iter.hasNext()) 
{ 
s1 = (String)iter.next(); 
s3 +=s1+"\n"; 
} 
BufferedReader in2 = 
new BufferedReader( 
new StringReader(s3)); 
PrintWriter out = 
new PrintWriter( 
new BufferedWriter( 
new FileWriter("data.txt"))); 
System.out.println("delete No"+deleteNumber); 
while( (s1 = in2.readLine())!=null) 
{ 
out.println(s1); 
} 
out.close(); 
}catch (NumberNotFoundException e) 
{ 
isDelete = false; 
System.out.println(deleteNumber+" no found :("); 
} 
}catch(IOException e){} 
} 


public long numberTokenizer(String s) 
throws IOException 
{ 
StringTokenizer st = 
new StringTokenizer(s," "); 
return Integer.valueOf((st.nextToken())).longValue(); 
} 


public void findData(long find)//查找数据 
throws IOException,NumberNotFoundException 
{ 
isFind = true; 
String s = "",findString =""; 
long i; 
DataMap dm = new DataMap(); 
BufferedReader in = 
new BufferedReader( 
new FileReader("data.txt")); 
while ((s=in.readLine())!=null) 
{ 
i=numberTokenizer(s); 
dm.put(i,s); 
} 
in.close(); 
try{ 
if(dm.containsKey( String.valueOf(find).toString())) 
{ 
findString = dm.get(find); 
System.out.println("学号"+find+"学生的资料是:"); 
System.out.println(findString); 
}else 
throw new NumberNotFoundException(); 
}catch (NumberNotFoundException e){ 
System.out.println(find+" no found :("); 
isFind = false; 
} 
} 


public static void print()//读取文本文件把数据打印到终端的方法 
throws IOException 
{ 
try{ 
BufferedReader in = 
new BufferedReader( 
new FileReader("data.txt")); 
String read = ""; 
while ((read = in.readLine())!=null) 
System.out.println(read); 
}catch(IOException e){} 
} 

public void numSort()//按学号排序 
throws IOException 
{ 
long i = 0; 
String s = ""; 
try{ 
DataArrayList dal = new DataArrayList(); 
BufferedReader in = 
new BufferedReader( 
new FileReader("data.txt")); 
while ((s=in.readLine())!=null) 
{ 
i=numberTokenizer(s); 
dal.add(i); 
} 
Collections.sort(dal); 
DataMap dm = new DataMap(); 
BufferedReader in2 = 
new BufferedReader( 
new FileReader("data.txt")); 
while ((s=in2.readLine())!=null) 
{ 
i=numberTokenizer(s); 
dm.put(i,s); 
} 
PrintWriter out = 
new PrintWriter ( 
new BufferedWriter( 
new FileWriter("data.txt"))); 
Iterator it = dal.iterator(); 
long temp = 0; 
String tempStr = ""; 
while (it.hasNext()) 
{ 
temp = Integer.valueOf((String)it.next()).longValue(); 
tempStr = dm.get(temp); 
out.println(tempStr); 
} 
out.close(); 
}catch(IOException e){} 
} 

public void rewrite() 
throws IOException,NumberNotFoundException 
{ 
try{ 
System.out.print("请输入你要修改的学生学号:"); 
BufferedReader in = 
new BufferedReader ( 
new InputStreamReader(System.in)); 
String inputLine = in.readLine(); 
long num = Integer.valueOf(inputLine).longValue(); 
findData(num); 
if(isFind) 
{ 
deleteData(num); 
System.out.print("请重新输入该学生的资料:"); 
String str = inputData(); 
addData(str); 
System.out.println("rewrite true!"); 
} 
}catch(IOException e){} 
catch(NumberNotFoundException e){} 
} 


public int count() 
throws IOException 
{ 
DataArrayList dal = new DataArrayList(); 
try{ 
String s = ""; 
long i =0; 
BufferedReader in = 
new BufferedReader( 
new FileReader("data.txt")); 
while ((s=in.readLine())!=null) 
{ 
i=numberTokenizer(s); 
dal.add(i); 
} 
}catch(IOException e){} 
return dal.size(); 
} 
} 
/* 
* 
* 
* TODO 这是个我们写的一个容器,继承公共类HashMap 
* 就相当一个数组 
* 
*/ 
class DataMap extends HashMap//一个存储数据的Map 
{ 
public void put(long i,String str)//把学号和数据放进这个Map 
{ //以后一个学号(key)对应的是一个人的数据(value) 
put(String.valueOf(i).toString(),str); 
} 
public void remove(long i)//接收学号,然后删除学号(key)和它对应的数据(value) 
{ 
remove(String.valueOf(i).toString().toString()); 
} 
public String get(long i)//接收一个学号,然后返回这个key对应的value 
{ 
String s = String.valueOf(i).toString(); 
if (!containsKey(s)) 
{ 
System.err.println("Not found Key: "+s); 
} 
return (String)get(s); 
} 
} 
/* 
* 
* 
* 
* TODO 这个类继承ArrayList 
* 用来按数字排序,在用学号排序时要用到它 
* 
*/ 
class DataArrayList extends ArrayList 
{ 
public void add(long num) 
{ 
String numToString = String.valueOf(num).toString(); 
add(numToString); 
} 
} 
/* 
* 
*  
* 
* TODO 增加的一个Exception,主要是在文件里没有要找 
* 的学号就抛出 
* 
*/ 
class NumberNotFoundException extends Exception 
{ 
public NumberNotFoundException() 
{} 
}