IO分两种流：字节流和字符流

IO分两种流:字节流和字符流

1、字节流 InputStream OutputStream 

2、字符流 Reader  Writer 

以上四个类都是抽象类 

具体实现：
字节流的实现为： FileInputStream  FileOutputStream 
字符流的实现为： FileReader    FileWriter 


字节流转换成字符流可以用 InputSteamReader  OutputStreamWriter 

再对字符流做处理：转换成BufferdReader  BufferedWriter，使其具有缓冲区 

字节流转字符流的实现如下：

FileInputStream fileInputStream = new FileInputStream("c:/text.txt");  //定义一个指向c:/testtxt 的字节流InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);//字节流转换成InputStreamReaderBufferedReader bufferedReader = new BufferedReader(inputSteamReader);//InputStreamReader 转换成带缓存的bufferedReader

将把读出来的内容赋值给字符 

String ss = new String();String s;while((s = bufferedReader.readLine())!=null){ss += s;}

例子：字节流到字符流，再使字符流具有缓冲区

FileOutputStream fileOutputStream = new FileOutputStream("c:/test.txt"); //定义一个指向c:/test.txt的字节流OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);//字节流转字符流BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);//使字符流具有缓冲区bufferedWriter.write(s);bufferedWriter.close();outputStreamWriter.close();fileOutputStream.close();