java编程 I/O--字符流-优快云博客

本文介绍如何使用字符流进行文件复制，并展示了两种方式：一种是通过FileReader和FileWriter直接逐字符读写；另一种则是利用BufferedReader和PrintWriter按行读取和写入，提高了效率。

字符流的使用：

import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class CopyCharacters { public static void main(String[] args) throws IOException { FileReader inputStream = null; FileWriter outputStream = null; try { inputStream = new FileReader("xanadu.txt"); outputStream = new FileWriter("characteroutput.txt"); int c; while ((c = inputStream.read()) != -1) { outputStream.write(c); } } finally { if (inputStream != null) { inputStream.close(); } if (outputStream != null) { outputStream.close(); } } } }

1、字符流每次 ”读/写“ 两个字节。

2、字节流到字符流的转换。

InputStreamReader 和OutputStreamWriter实现从字节流到字符流的转换。

Buffered I/O

import java.io.FileReader; import java.io.FileWriter; import java.io.BufferedReader; import java.io.PrintWriter; import java.io.IOException; public class CopyLines { public static void main(String[] args) throws IOException { BufferedReader inputStream = null; PrintWriter outputStream = null; try { inputStream = new BufferedReader(new FileReader("xanadu.txt")); outputStream = new PrintWriter(new FileWriter("characteroutput.txt")); String l; while ((l = inputStream.readLine()) != null) { outputStream.println(l); } } finally { if (inputStream != null) { inputStream.close(); } if (outputStream != null) { outputStream.close(); } } } }