Java输入输出（7）---向指定文件，指定位置插入内容

public class InsertContent

{

public static void insert(String fileName,long pos,String insertContent) throws IOException

{

RandomAccessFile raf = null;

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

FileOutputStream tmpOut = null;

FileInputStream tmpIn = null;

tmp.deleteOnExit();

try

{

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

tmpOut = new FileOutputStream(tmp);

tmpIn = new FileInputStream(tmp);

raf.seek(pos);

byte[] bbuf = new byte[64];

int hasRead = 0;

while((hasRead = raf.read(bbuf)) > 0)

{

tmpOut.write(bbuf,0,hasRead);

}

raf.seek(pos);

raf.write(insertContent.getBytes());

while((hasRead = tmpIn.read(bbuf))>0)

{

raf.write(bbuf,0,hasRead);

}

}

finally

{

raf.close();

}

}

public static void main(String[] args) throws IOException

{

insert("InsertContent.java", 45,"插入的内容\r\n");

}

}