File类在IO中的作用

当以文件作为数据源或目标时，除了可以使用字符串作为文件以及位置的指定以外，也可以使用 File 类指定

import java.io.*;
public class FileInIODemo {
    public static void main(String[] args) {
        BufferedReader bufferedReader=null;
        BufferedWriter bufferedWriter=null;
        try{
            bufferedReader =new BufferedReader(new FileReader(new File("d:/javaStudy/javaworkspace/dd.txt")));
            bufferedWriter =new BufferedWriter(new FileWriter(new File("d:/javaStudy/javaworkspace/fileinio.txt")));
            String str="";
            int i=1;
            while((str=bufferedReader.readLine())!=null){
                bufferedWriter.write(i+","+str);
                bufferedWriter.newLine();
                i++;
            }
            bufferedWriter.flush();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            try{
                if(bufferedReader!=null){
                    bufferedReader.close();
                }
                if(bufferedWriter!=null){
                    bufferedWriter.close();
                }
            }catch (Exception e){
                    e.printStackTrace();
            }
        }
    }
}