父类-------------------------------子类（唯一的弊端，不能指定码表，只能使用平台默认码表） InputStreamReader----------------FileReader OutputStreamWriter----------------FileWriter
FileReader in = new FileReader("a.txt"); FileWriter out = new FileWriter("a88a.txt"); int len=0; char[] chars = new char[1024]; while ((len=in.read(chars))!=-1){ out.write(chars,0,len); out.flush(); } //释放资源 in.close(); out.close();