JAVA基于缓冲的文件读写操作

File f2 = new File("e://index.java");
	    BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(f2),"GB2312"));

	    String str = "";
	    String line = reader.readLine();
	    while(line != null){
	    	str += line + "\r\n";
	    	line = reader.readLine();
	    }
	    System.out.println(str);
	    reader.close();

	    BufferedWriter write = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(f2)));
	    write.write("hello.....");
	    write.flush();
	    write.close();