java集合类实现简单的学生信息管理系统

package jihe;
import java.util.Scanner;
public class Student {
private String sno;
private String sname;
private int grade;
private int age;
private String sex;
private String sdept;

public Student() {

}

public Student(String sno, String sname,int grade, int age, String sex, String sdept) {
	
	this.sno = sno;
	this.sname=sname;
	this.grade = grade;
	this.age = age;
	this.sex = sex;
	this.sdept = sdept;
}
public String getSno() {
	return sno;
}

public String getSname() {
	return sname;
}

public int getAge() {
	return age;
}


public String getSex() {
	return sex;
}


public String getSdept() {
	return sdept;
}


public int getGrade() {
	return grade;
}

public void display()
{System.out.print(sno+" "+sname+" "+grade+" "+age+" "+sex+" "+sdept);
System.out.println();
}
public void setGrade(int g)
{grade=g;
}
}

package jihe;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;

public class Studentop {
	static Scanner cin=new Scanner(System.in);
public Studentop() {
		
	}
private ArrayList<Student>ss=new  ArrayList<Student>();
private HashMap<String,Integer>mp=new HashMap<String,Integer>();
public  void add()
{String sno,sname,ssex,sdept;
int grade,age;



while(true)
{sno=cin.next();
if(sno.equals("end"))
	break;
sname=cin.next();
grade=cin.nextInt();

age=cin.nextInt();
ssex=cin.next();
sdept=cin.next();
Student s1=new Student(sno,sname,grade,age,ssex,sdept);
ss.add(s1);
mp.put(sno,ss.size()-1);
}
}
public void show()
{
	for(int i=0;i<ss.size();i++)
ss.get(i).display();

}
public int search(String sno)
{
	return mp.get(sno);

}
public void update(String sno)
{int a=search(sno);
System.out.println("输入新成绩");
int g=cin.nextInt();
ss.get(a).setGrade(g);
}
public void delete(String sno)
{int a=search(sno);
ss.remove(a);
mp.remove(sno);
}
public  void showstu(String sno)
{int a=search(sno);
ss.get(a).display();
}
public void wj() throws IOException
	{
	BufferedWriter bw=new BufferedWriter(new FileWriter("F:\\xuesheng.txt"));
	for(int i=0;i<ss.size();i++)
	{
	bw.write(ss.get(i).getSno()+" "+ss.get(i).getSname()+" "+ss.get(i).getGrade()+" "+ss.get(i).getAge()+" "+ss.get(i).getSex()+" "+ss.get(i).getSdept());
	bw.newLine();
	}
	bw.flush();
	}


public static void main(String args[]) throws IOException
{
Studentop s1=new Studentop();
s1.add();
s1.show();

//s1.delete("20171754");
s1.update("20171754");
s1.showstu("20171754");
s1.wj();
}
}