Java中的IO流操作 ObjectInputStream和ObjectOutputStream实现信息的增删功能

ObjectInputStream循环读取文件中的对象个数，要做对象为空的catch异常

package object.io;

import java.io.Serializable;

public class Student implements Serializable{
    @Override
    public String toString() {
        return code+"	"+name+"	"+age+"	"+score;
    }
    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public double getScore() {
        return score;
    }
    public void setScore(double score) {
        this.score = score;
    }
    private int code;
    private String name;
    private int age;
    private double score;
    public Student(int code, String name, int age, double score) {
        super();
        this.code = code;
        this.name = name;
        this.age = age;
        this.score = score;
    }
    public Student() {
        super();
    }
    
}

package object.io;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;



public class StudentMain {
    static Scanner sc=new Scanner(System.in);
    //static List<Student> list=new ArrayList<Student>();
    static List<Student> list;
    //static List<Student> list2=new ArrayList<Student>();
//    static List<Student> list2;
    
    //录入学生信息
    public static void add() throws Exception{
        
    
        try {
            FileInputStream input=new FileInputStream("D:\Program Files (x86)\io\Student.txt");
            ObjectInputStream oip=new ObjectInputStream(input);
            list=new ArrayList<Student>();
            while(true){
                //list.add(student);
                if((oip.available())!=-1){
                    Student student=(Student) oip.readObject();
                    list.add(student);
                    
                }else{
                    break;
                }
                
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
        } 
        FileOutputStream output=new FileOutputStream("D:\Program Files (x86)\io\Student.txt");
        ObjectOutputStream oop=new ObjectOutputStream(output);
        boolean flag=true;
        while(flag){
            System.out.println("请输入学生的学号:");
            int code=sc.nextInt();
            if (code!=0) {
                System.out.println("请输入学生的姓名：");
                String name=sc.next();
                System.out.println("请输入学生的年龄：");
                int age=sc.nextInt();
                System.out.println("请输入学生的成绩：");
                double score=sc.nextDouble();
                Student s=new Student(code, name, age, score);
                list.add(s);
                
            }else{
                flag=false;
            }
            
            
        }
        for(Student student2:list){
            oop.writeObject(student2);
        }
        
    }
    
    
    //展示学生信息
    public static void show(){
        try {
            FileInputStream input=new FileInputStream("D:\Program Files (x86)\io\Student.txt");
            ObjectInputStream oip=new ObjectInputStream(input);
            list=new ArrayList<Student>();
            while(true){
                //list.add(student);
                if((oip.available())!=-1){
                    Student student=(Student) oip.readObject();
                    list.add(student);
                    
                }else{
                    break;
                }
                
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
        } 
        try {
            System.out.println("学号	姓名	年龄	成绩");
            FileInputStream input=new FileInputStream("D:\Program Files (x86)\io\Student.txt");
            ObjectInputStream oip=new ObjectInputStream(input);
            while(true){
                //list.add(student);
                if((oip.available())!=-1){
                    Student student=(Student) oip.readObject();
                    System.out.println(student.getCode()+"	"+student.getName()+"	"+student.getAge()+"	"+student.getScore());
                }else{
                    break;
                }
                
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
        } 
        
    }
    
    public static void delete() throws IOException, ClassNotFoundException{
        //先获取到文本中对象到集合
        list=new ArrayList<Student>();
        try {
            FileInputStream input=new FileInputStream("D:\Program Files (x86)\io\Student.txt");
            ObjectInputStream oip=new ObjectInputStream(input);
            while(true){
                //list.add(student);
                if((oip.available())!=-1){
                    Student student=(Student) oip.readObject();
                    list.add(student);
                    
                }else{
                    break;
                }
                
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
        } 
        //找到集合中想要删除的学号
        System.out.println("请输入要删除的学生学号：");
        int code=sc.nextInt();
        boolean flag = false;
        for(int i=0;i<list.size();i++){
            if(list.get(i).getCode()==code){
                list.remove(i);
                System.out.println("删除成功");
                flag=true;
                break;
            }
        }
        if(flag==false){
            System.out.println("输入的学号不存在");
        }
        
        
        //重新将更过的集合写入文本中
        FileOutputStream output=new FileOutputStream("D:\Program Files (x86)\io\Student.txt");
        ObjectOutputStream oop=new ObjectOutputStream(output);
        for(Student student3:list){
            oop.writeObject(student3);
        }
        
        
    }
    public static void main(String[] args) throws Exception {
        while(true){
            System.out.println("1.显示  2.增加  3.删除  0.退出");
            System.out.println("请输入选择：");
            int num=sc.nextInt();
            switch(num){
            case 1:
                show();
                break;
            case 2:
                add();
                break;
            case 3:
                delete();
                break;
            case 0:
                System.out.println("退出系统");
                return;
            }
            
        }
    }
}