Java RandomAccessFile的使用

public class FileDemo 
{
    public static void main(String[] args) throws Exception
    {
        Student stu1 = new Student(1,"chichao");
        Student stu2 = new Student(1,"caijing");
        RandomAccessFile ref = new RandomAccessFile("D:"+File.separator+"test"+File.separator+"hello.txt","rw");//提供了对文件的读和写
        stu1.writeInfo(ref);
        stu2.writeInfo(ref);
        Student stu3 = new Student();
        ref.seek(0);//进行写操作之后，指针已经被移到了末尾，在进行读之前，要先把指针重新置到开头
        for(long i=0;i<ref.length();i=ref.getFilePointer())//获取下一个要读写的位置
        {
            stu3.readInfo(ref);
            System.out.println(stu3.name+" "+stu3.num);
        }
        ref.close();
    }
}

 

 

class Student 
{
    int num;
    String name;
    public Student()
    {
        
    }
    public Student(int num,String name)
    {
        this.num = num;
        this.name = name;
    }
    
    public void writeInfo(RandomAccessFile ref) throws IOException
    {
        ref.writeInt(num);
        ref.writeUTF(name);//向输出流中写入字符串，并在字符串的开始位置开辟两个字节用来存放该字符串字节的长度
    }
    
    public void readInfo(RandomAccessFile ref) throws IOException
    {
        num = ref.readInt();
        name = ref.readUTF();
    }
}