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 2007-10-16*/ /** * @author 月 * @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月\n"+ "\t\t上**学院**系\n"+ "\t\tQQ:6033*****\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 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 static void timeOut(double sec)//停顿短暂时间的一个方法完全可以不要这个功能 { double seconds = sec; long t = System.currentTimeMillis()+(int)(seconds*1000); while ((System.currentTimeMillis())<t) ; } 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(); } } /* * * @author RangWei * TODO 这是个我们写的一个容器,继承公共类HashMap * 大概的功能就相当一个数组 * */ 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); } } /* * * @author RangWei * * 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); } } /* * * @author RangWei * * 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() {} }
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