conn.getInputStream()返回InputStream对象的字节流,通过new InputStreamReader(Inputstream inputstream)将字节流转换为字符流,也可以指定字符流的编码格式
InputStreamReader is=new InputStreamReader(Inputstream inputstream,"编码格式的名称");
BufferedReader bf=new BufferedReader(InputStreamReader is )从字符输入流中缓冲字符,方便数据的读取。bf.readLine()读取一行,读取不到就返回null