copyfile.java

java小程序

import java.io.*;
public class CopyFile
{
public static void main(String args[]) throws Exception
{
BufferedReader br=new BufferedReader(new FileReader("line.txt"));
BufferedWriter bw=new BufferedWriter(new FileWriter("linenum.txt"));
String s,space=" ";
int num=0;
while(br.ready())
{
s=br.readLine();
num++;
bw.write(String.valueOf(num));//整数转化成字符串；
bw.write(space);
bw.write(s);
bw.newLine();
}
bw.close();
}
}