java.io 对字节流和字符流的讨论

IO分两种流

字节流 InputStream OutputStream

字符流 Reader  Writer

他们都是抽象类

具体实现
字节流 FileInputStream  FileOutputStream
字符流 FileReader    FileWriter


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

转换成BufferdReader  BufferedWriter 他们具有缓冲区

例如：读取文件 从字节流输入到字符流输入
定义一个字节流：
Java代码
FileInputStream fileInputStream = new FileInputStream("d:/aa.txt");  // 定义一个指向D:/TEXT.TXT 的字节流  
 
InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);  
//字节流转换成InputStreamReader  
 
BufferedReader bufferedReader = new BufferedReader(inputSteamReader);  
//InputStreamReader 转换成带缓存的bufferedReader 

FileInputStream fileInputStream = new FileInputStream("d:/text.txt");  // 定义一个指向D:/TEXT.TXT 的字节流

InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
//字节流转换成InputStreamReader

BufferedReader bufferedReader = new BufferedReader(inputSteamReader);
//InputStreamReader 转换成带缓存的bufferedReader



可以把读出来的内容赋值给字符
Java代码
 
String ss = new String();  
String s;  
while((s = bufferedReader.readLine())!=null){  
    ss += s;  
} 


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


例如：写入文件  从字节流输出到字符流输出
Java代码
 
FileOutputStream fileOutputStream = new FileOutputStream("d:/text.txt"); //定义一个  
 
指向D:/TEXT.TXT文件   
 
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);  
 
BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);  
 
bufferedWriter.write(s);  
 
bufferedWriter.close();  
outputStreamWriter.close();  
fileOutputStream.close();