对象流改造集合

HashMap与对象流组合应用(主函数部分实现)

public static void main(String[] args) throws Exception{
    //用File可判断文件是否为空，否则出现异常
    File file = new File("X:\\xxx.xxx");
    long len = file.length();
    Map<String, Person> map = null;
    if(len>0){//有数据
       FileInputStream fis = new FileInputStream(file);
       ObjectInputStream ois = new ObjectInputStream(fis);
       Map<String, Person> map = (Map<String, Person>)ois.readObject();
    }else{
        map = new HashMap<String, Person>();
    }
    
    do{
        System.out.println("************请输入如下选项************");
        System.out.println("\t\t\t1.信息录入");
        System.out.println("\t\t\t2.信息查询");
        System.out.println("\t\t\t3.信息修改");
        System.out.println("\t\t\t4.信息删除");
        System.out.println("\t\t\t5.退出");
        Scanner input = new Scanner(System.in);
        int flag = input.nextInt();
        switch(flag){
            case 1:
                Operation.addPerson(input,map);
                break;
            case 2:
                Operation.getAllPerson(map);
                break;
            case 3:
                break;
            case 4:
                break;
            case 5:
                System.out.println("退出成功");
                FileOutputStream fos = new FileOutputStream("X:\\xxx.xxx");
                ObjectOutputStream oos = new ObjectOutputStream(fos);
                oos.writeObject(map);
                oos.close();
                fos.close();
                System.exit(0);
                break;
        }
    }while(true);
}