去除网页拷贝下来的源代码行号

import java.io.*;

class SubLineNum{
public static void main(String []sss){
try{
BufferedReader bf = new BufferedReader(new FileReader("c.txt"));
FileWriter fw = new FileWriter("d .txt");
String line = null;
StringBuffer sb = new StringBuffer ();
while((line = bf.readLine())!=null){
String lin = line.substring(line.indexOf(" ")+1)+"\t\n";
fw.write(lin,0,lin.length()); 
}
fw.flush();
fw.close();

}catch(IOException ex){
ex.printStackTrace();
}
}
}