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设计学生类Student,属性:学号(整型);姓名(字符串),选修课程(名称)及课程成绩(整型)。编写一个控制台程序,能够实现Student信息的保存、读取。具体要求:(1)提供Student信息的保存功能:通过控制台输入若干个学生的学号、姓名以及每个学生所修课程的课程名和成绩,将其信息保存到data.dat中;(2)数据读取显示:能够从data.dat文件中读取学生及其课程成绩并显示于控制台。
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("退出请输入#0");
System.out.println("录入学生信息请输入#1");
System.out.println("查看学生信息请输入#2");
System.out.println("保存学生信息请输入#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("已退出输入");
break;
}
else if(s.equals("#1")) {
String temp=null;
System.out.println("请依次“输入学号#姓名#选修课程#课程成绩”");
while(true) {
System.out.print("学号:");
int No=scan.nextInt();
stu.setNo(No);
System.out.print("姓名:");
String Name=scan.next();
stu.setName(Name);
System.out.print("选修课程:");
String Sub=scan.next();
stu.setSubject(Sub);
System.out.print("课程成绩:");
int Score=scan.nextInt();
stu.setScore(Score);
data.add(stu);
System.out.println("输入exit结束录入,输入其他继续录入");
temp=scan.next();
if(temp.equals("exit")) {
System.out.println("已退出录入");
break;
}
}
}
else if(s.equals("#2")) {
List<Student> stus=Student.readStudent("data.dat");
if(stus==null||stus.size()==0) {
System.out.println("无学生信息!");
}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("信息已保存");
}else {
System.out.println("无需要保存的学生信息!");
}
}
else {
System.out.println("指令错误!");
Student.show();
}
}
scan.close();
}
}