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; }