转换流读写文件

package com.io;  
import java.io.*;  
public class OutputStreamWriterDemo01    
{    
    public static void main(String args[]) throws Exception{    //所有异常抛出     
        //写入数据  
        File file=new File("d:"+File.separator+"test.txt");    
        Writer writer=null;     //字符输出流     
        writer=new OutputStreamWriter(new FileOutputStream(file));  //字节流变为字符流     
        String str="hello world!!!!";       
        writer.write(str);  //使用字符流输出     
        writer.close();  
          
        //读取文件  
          
        File f = new File("d:" + File.separator + "test.txt") ;     
        Reader reader = null ;    
        reader = new InputStreamReader(new FileInputStream(f)) ;    // 将字节流变为字符流     
        char c[] = new char[1024] ;    
        int len = reader.read(c) ;  // 读取     
        reader.close() ;    // 关闭     
        System.out.println(new String(c,0,len)) ;    
    }    
}    

　　java提供将字节流转化为字符流读写方式的OutputStreamWriter和InputStreamReader