java如何读写txt文件

package readAndWrite;
import java.io.*;
public class TXT {
    public static void main(String[] args) throws IOException
    {
        String readSource = "F:\\ReadTXT.txt";
        FileInputStream fis = new FileInputStream(readSource);
        InputStreamReader isr = new InputStreamReader(fis);
        BufferedReader  br =  new BufferedReader(isr);
        String writeDest = "F:\\WriteTXT.txt";
        File file = new File(writeDest);
        FileWriter fw = new FileWriter(file);
        BufferedWriter bw = new BufferedWriter(fw);
        String line;
        for(;(line=br.readLine())!=null;){
            bw.write(line);
            bw.write("\r\n");
        }
        bw.close();
        fw.close();
        br.close();
        isr.close();
        fis.close();
    }
}