数据流InputStream转字符串

 public static String ScreamToString(InputStream in) throws Exception{     //定义一个内存输出流     ByteArrayOutputStream out = new ByteArrayOutputStream();     int len=0;     byte[] bt=new byte[1024];     while((len=in.read(bt))!=-1){        out.write(bt,0,len);     }    String content=new String(out.toByteArray());// String content=new String(out.toByteArray(),"gbk");//使用构造函数,不指定编码，默认是utf-8     return content; }