IO

package bbb;
import java.io.*;
public class ccc {
    public static void main(String[] args) throws IOException{
        String str="123456sad";
        File f1=new File("D://data.txt");
        FileWriter fw=new FileWriter(f1);
        BufferedWriter bw=new BufferedWriter (fw);
        bw.write("王程");
        bw.newLine();
        bw.write(str);
        bw.newLine();
        bw.close();
        fw.close();

package wink;
import java.io.*;
public class eeeee {
    public static void main(String[] args) throws IOException{
         File f1 = new File("D://asd.txt");
            FileReader fw = new FileReader(f1);
            BufferedReader bw =new BufferedReader(fw);
            String str;
            while((str=bw.readLine())!=null){
                System.out.println(str);
            }
            bw.close();
            fw.close();
    }

}

        
    }

}