关于RandomAccessFile用法的一个小例子，可是一直抛出异常

[rambler漫步]

我这个例子是想用一个RandomAccessFile的对象将Student这个类写进Student1.txt文档中，可是一直抛出异常，源代码在这里，求解啊：
import java.io.*;

public class WriteStudent1 {
public static void main(String[] args) throws IOException {
File f = new File("e:/Student1.txt");
Student[] s = new Student[3];
s[0] = new Student(18);
s[1] = new Student(19);
//Student s3 = new Student(20, "Jane");

RandomAccessFile raf = new RandomAccessFile(f, "rw");

for(int i=0; i<2; i++) {
s[i].writeStudent(raf);
}

for(int i=0; i<2; i++) {
Student stu = s[i].readStu(raf);
System.out.println(stu);
}

raf.close();
}

}

class Student {
int age;
//String name;

public Student(int age) {
this.age = age;
//this.name = name;
}

public String toString() {
return "Age: " + age; //+ "Name: " + name;
}

public void writeStudent(RandomAccessFile raf) throws IOException {
raf.writeInt(age);
//raf.writeBytes(name);
}

public Student readStu(RandomAccessFile raf) throws IOException {
int i = raf.readInt();
return new Student(i);
}
}

[FFF9527]

    public static void main(String[] args) throws IOException
    {
        File f = new File("e:/Student1.txt");
        Student[] s = new Student[3];
        s[0] = new Student(18);
        s[1] = new Student(19);
        // Student s3 = new Student(20, "Jane");

        RandomAccessFile raf = new RandomAccessFile(f, "rw");

        for (int i = 0; i < 2; i++)
        {
            s[i].writeStudent(raf);
        }
        
        raf.close();
        
        RandomAccessFile raf01 = new RandomAccessFile(f, "rw");
        for (int i = 0; i < 2; i++)
        {
            Student stu = s[i].readStu(raf01);
            System.out.println(stu);
        }

        raf01.close();
    }

以上代码是很不规范的，流必须在用try-finally 包裹 最后在finally 中将流关闭

[FFF9527]

或者在两个for之间加入

raf.seek(0);

你写文件的时候，指针跟着移动的。但是读文件必须从头开始，所以指针要设为0

[xlhb]

RandomAccessFile raf = new RandomAccessFile(f, "rw");

for (int i = 0; i < 2; i++)
{
s[i].writeStudent(raf);
}
raf.seek(0);

for (int i = 0; i < 2; i++)
{
Student stu = s[i].readStu(raf);
System.out.println(stu);
}

raf.close();

读的时候指针必须移到初始位置，用到seek方法，但是你必须把中间的那个raf.close()方法给删除。

[rambler漫步]

感谢楼上各位，明白了！！！！！！！！！！！！