設計學生類Student，屬性：學號（整型）；姓名（字串），選修課程（名稱）及課程成績（整型）。編寫一個控制檯程式，能夠實現Student資訊的儲存、讀取。具體要求：（1）提供Student資訊的儲存功能：通過控制檯輸入若干個學生的學號、姓名以及每個學生所修課程的課程名和成績，將其資訊儲存到data.dat中；（2）資料讀取顯示：能夠從data.dat檔案中讀取學生及其課程成績並顯示於控制檯。

import java.io.*;
import java.util.*;
public class Student {
	private int no;
	private String name;
	private String subject;
	private int score;
	public int getNo() {
		return no;
	}
	public void setNo(int no) {
		this.no = no;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getSubject() {
		return subject;
	}
	public void setSubject(String subject) {
		this.subject = subject;
	}
	public int getScore() {
		return score;
	}
	public void setScore(int score) {
		this.score = score;
	}
	@Override
	public String toString() {
		return "Student [no=" + no + ", name=" + name + ", subject=" + subject + ", score=" + score + "]";
	}
	public static void saveStudent(List<Student> students) throws IOException {
		try {
			BufferedWriter out=new BufferedWriter(new FileWriter("data.dat",true));
			StringBuffer s=new StringBuffer();
			for(int i=0;i<students.size();i++) {
				Student stu=students.get(i);
				s.append(stu.getNo()+"#"+stu.getName()+"#"+stu.getSubject()+"#"+stu.getScore());
				out.write(s.toString());
				out.write("\n");
			}
			out.flush();
			out.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
	}
	public static List<Student> readStudent(String filename) throws IOException{
		File file=new File(filename);
		List<Student> data=new ArrayList<Student>();
		if(file.exists()) {	
			BufferedReader in=new BufferedReader(new InputStreamReader(new FileInputStream(file)));
			String s=null;
			String[] str=null;
			while(true) {
				s=in.readLine();
				if(s!=null) {
					Student stu=new Student();
					str=s.split("#");
					stu.setNo(Integer.parseInt(str[0]));
					stu.setName(str[1]);
					stu.setSubject(str[2]);
					stu.setScore(Integer.parseInt(str[3]));
					data.add(stu);
				}
				else break;
			}
			in.close();
		}
		return data;
	}
	public static void show() {
		System.out.println("退出請輸入#0");
		System.out.println("錄入學生資訊請輸入#1");
		System.out.println("檢視學生資訊請輸入#2");
		System.out.println("儲存學生資訊請輸入#3");
	}
}
 

import java.io.IOException;
import java.util.*;
public class Main {

	public static void main(String[] args) throws IOException {
		Scanner scan=new Scanner(System.in);
		List<Student>data=new ArrayList<Student>();
		Student.show();
		Student stu=new Student();
		while(true) {
			String s=scan.next();
			if(s.equals("#0")) {
				System.out.println("已退出輸入");
				break;
			}
			else if(s.equals("#1")) {
				String temp=null;
				System.out.println("請依次“輸入學號#姓名#選修課程#課程成績”");
				while(true) {
					System.out.print("學號：");
					int No=scan.nextInt();
					stu.setNo(No);
					System.out.print("姓名：");
					String Name=scan.next();
					stu.setName(Name);
					System.out.print("選修課程：");
					String Sub=scan.next();
					stu.setSubject(Sub);
					System.out.print("課程成績：");
					int Score=scan.nextInt();
					stu.setScore(Score);
					data.add(stu);
					System.out.println("輸入exit結束錄入，輸入其他繼續錄入");
					temp=scan.next();
					if(temp.equals("exit")) {
						System.out.println("已退出錄入");
						break;
					}
				}
			}
			else if(s.equals("#2")) {
				List<Student> stus=Student.readStudent("data.dat");
				if(stus==null||stus.size()==0) {
					System.out.println("無學生資訊！");
				}else {
					for(int i=0;i<stus.size();i++) {
						System.out.println(stus.get(i).toString());
					}
				}
			}
			else if(s.equals("#3")) {
				if(data.size()>0) {
					Student.saveStudent(data);
                                        data.clear();
					System.out.println("資訊已儲存");
				}else {
					System.out.println("無需要儲存的學生資訊！");
				}
			}
			else {
				System.out.println("指令錯誤！");
				Student.show();
			}
		}
		scan.close();
	}
}