//向指定文件的指定位置插入文件使用RandomAccessFile类创建文件

import java.io.*;

public class Insert

{

public static void insert(String s,String name,long index)

throws IOException

{

File tmp = File.createTempFile("tmp",null);

tmp.deleteOnExit();

try(RandomAccessFile ra = new RandomAccessFile(name,"rw");

FileInputStream fi = new FileInputStream(tmp);

FileOutputStream fo = new FileOutputStream(tmp))

{

System.out.print(ra.getFilePointer());

ra.seek(index);

byte[] b =new byte[32];

int hasRead = 0;

while ((hasRead = ra.read(b))>0)

{

fo.write(b, 0 , hasRead);

}

ra.seek(index);

ra.writeBytes(s);

hasRead = 0;

while ((hasRead = fi.read(b))>0)

{

ra.write(b, 0 , hasRead);

}

}

catch (IOException ex)

{

ex.printStackTrace();

}

}

public static void main(String[] args)

throws IOException

{

insert("*********************************","a.txt", 10);

}

}