课堂测试四（文件读写）

学生信息管理系统

（本程序以文本方式存储数据，不通过数组，直接对文件进行操作）

学生类

Student.java

public class Student {
    private String stunumber;            //学号
    private String name;                //姓名
    private int age;                    //年龄
    private boolean sex;                //性别
    private double score;                //分数
    
    /***构造方法***/
    public Student(String num,String name,int age,boolean sex,double score){
        stunumber = num;
        this.name = name;
        this.age = age;
        this.sex = sex;
        this.score = score;
    }
    
    /***get函数***/
    public String getNum(){                //取学号
        return stunumber;
    }
    public String getName(){            //取姓名
        return name;
    }
    public int getAge(){                //取年龄
        return age;
    }
    public boolean getSex(){            //取性别
        return sex;
    }
    public double score(){                //取分数
        return score;
    }
    
    /***set函数***/
    public void setNum(String num){                //设置学号
         stunumber = num;
    }
    public void setName(String name){            //设置姓名
         this.name = name;
    }
    public void setAge(int age){                //设置年龄
         this.age = age;
    }
    public void setSex(boolean sex){            //设置性别
         this.sex = sex;
    }
    public void score(double score){                //设置分数
         this.score = score;
    }
}

管理类

StudentManager.java

import java.io.*;
import java.util.Scanner;
public class StudentManager {
    
    /***主函数***/
    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(System.in);
        while(true){
            menu();
            int n = in.nextInt();
            switch(n){
            case 1:showStudent();break;
            case 2:
                System.out.println("请依次输入学生的学号、姓名、年龄、性别(true/false)、分数：");
                addStudent(in.next(),in.next(),in.nextInt(),in.nextBoolean(),in.nextDouble());
                break;
            case 3:
                System.out.println("输入要删除的学生的学号：");
                deleteStudent(in.next());
                break;
            case 4:
                System.out.println("输入要修改的学生的学号，及修改后的姓名、年龄、性别(true/false)、分数：");
                updateStudent(in.next(),in.next(),in.nextInt(),in.nextBoolean(),in.nextDouble());
                break;
            case 5:
                System.out.println("输入要查询的学生的学号：");
                selectStudent(in.next());
                break;
            }
        }
    }
    
    /***显示菜单***/
    public static void menu(){
        System.out.println("**********************************************************");
        System.out.println("                                           石家庄铁道大学信息科学与技术学院");
        System.out.println("                                                        学生信息管理系统V2.0");
        System.out.println("**********************************************************");
        System.out.println("                     1.遍历输出学生信息；");
        System.out.println("                     2.新学生信息录入；");
        System.out.println("                     3.删除学生信息；");
        System.out.println("                     4.修改学生信息；");
        System.out.println("                     5.查询学生信息；");
        System.out.println("**********************************************************");
    }
    
    /***显示所有学生信息 ***/
    public static void showStudent() throws IOException{
        File file = new File("student.dat");
        BufferedReader reader = null;
        reader = new BufferedReader(new FileReader(file));
        String tempString = null;
        while ((tempString = reader.readLine()) != null) {
            System.out.println(tempString);
        }
    }
    
    /***添加学生信息***/
    public static void addStudent(String stunumber,String name,int age,boolean sex,double score) throws IOException{
        FileWriter writer = new FileWriter("student.dat",true);
        String s;
        if(sex)
            s = "女";
        else s = "男";
        writer.append(stunumber + " " + name + " " + age + " " + s + " " + score + "
");
        writer.close();
        System.out.println("添加成功！");
    }
    
    /***删除学生信息 ***/
    public static void deleteStudent(String stunumber) throws IOException{
        
        StringBuffer all = new StringBuffer();
        File file = new File("student.dat");
        String temp;
        BufferedReader reader = new BufferedReader(new FileReader(file));
        
        while((temp = reader.readLine()) != null){
            if(!temp.startsWith(stunumber))
                all.append(temp + "
");
        }
        reader.close();
        
        BufferedWriter writer = new BufferedWriter(new FileWriter(file));
        writer.write(all.toString());;
        writer.close();
        System.out.println("删除成功！");
    }
    
    /***更新学生信息***/
    public static void updateStudent(String stunumber,String name,int age,boolean sex,double score) throws IOException{
        StringBuffer all = new StringBuffer();
        File file = new File("student.dat");
        String temp,s;
        if(sex)
            s = "女";
        else s = "男";
        BufferedReader reader = new BufferedReader(new FileReader(file));
        
        while((temp = reader.readLine()) != null){
            if(!temp.startsWith(stunumber))
                all.append(temp + "
");
            else all.append(stunumber + " " + name + " " + age + " " + s + " " + score + "
");
        }
        reader.close();
        
        BufferedWriter writer = new BufferedWriter(new FileWriter(file));
        writer.write(all.toString());;
        writer.close();
        System.out.println("修改成功！");
    }
    
    /***查询学生信息***/
    public static void selectStudent(String stunumber) throws IOException{
        File file = new File("student.dat");
        BufferedReader reader = new BufferedReader(new FileReader(file));
        String stuLine;
        while((stuLine = reader.readLine()) != null)
        {
            if(stuLine.startsWith(stunumber))
            {
                System.out.println(stuLine);
                return;
            }
        }
        System.out.println("查询结果为空！");
    }
}