studentmanage.txt

提供学生管理系统

import java.io.BufferedReader; 
import java.io.BufferedWriter; 
import java.io.File; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.FileWriter; 
import java.io.IOException; 

import java.io.InputStreamReader; 
import java.io.PrintWriter; 
import java.io.StringReader; 
import java.util.ArrayList; 
import java.util.Collection; 
import java.util.Collections; 
import java.util.HashMap; 
import java.util.Iterator; 
import java.util.StringTokenizer; 

/* 
* Created on 2005-1-11 
*/ 

/** 
* @author 让炜 
* @since 1.0 
* 
* TODO 学生成绩管理系统 
* 通过学号查找,修改,删除数据 
* 
*/ 
public class LittleProgram 
{ 
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; 
do{ 
LittleProgram lp = new LittleProgram(); 
System.out.println(); 
System.out.println("\t####################################"); 
System.out.println(); 
System.out.println("\t\t Java学生成绩管理系统1.1"); 
System.out.println("\t\t请用学号查找,修改,删除数据"); 
System.out.println(); 
System.out.println("\t####################################\n"); 
System.out.print("1.增加数据:\n"+ 
"2.查找数据:\n"+ 
"3.删除数据:\n"+ 
"4.清除所有数据:\n"+ 
"5.把数据全部打印到屏幕\n"+ 
"6.把成绩按学号排序\n"+ 
"7.修改数据\n"+ 
"8.统计已记录成绩学生数\n"+ 
"9.关于作者\n"+ 
"0.退出程序.\n" + 
"输入:"); 
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; 
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."); 
timeOut(1); 
}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); 

timeOut(2); 
}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!"); 
timeOut(1); 
}break; 
case 4: { 
lp.clearData();//4.清除所有数据 
timeOut(1); 
}break; 
case 5: { 
print();//5.把数据全部打印到屏幕 
timeOut(2); 
}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(); 
timeOut(2); 
}break; 
case 7: { 
lp.rewrite();//7.修改数据 
timeOut(2); 
}break; 
case 8: { 
int count = lp.count(); 
System.out.println("共有"+count+"个学生已经记录."); 
timeOut(2); 
}break; 
case 9: { 
System.out.print("\t\t让炜\n"+ 
"\t\t上海电力学院通信工程系\n"+ 
"\t\tQQ:254482170\n"); 
timeOut(4); 
}break; 
}while (choice != 0); 
System.out.println("Bye! ^-^"); 
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 成绩\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 mark = Integer.valueOf(str.nextToken()).doubleValue();//分数 
all = String.valueOf(num) +" , "+ 
name +" , "+ 
sex +" , "+ 
String.valueOf(mark);//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 S