GET /devices/79146/datastreams/KEY HTTP/1.1 Host: api.heclouds.com api-key: pmWLtnkDBSreKfvg7GsClUXdXa4A Connection: close
注意：Connection: close后面有两个\r\n
返回：
HTTP/1.1 200 OK Date: Sun, 20 Sep 2015 09:02:44 GMT Content-Type: application/json Content-Length: 136 Connection: close Server: Apache-Coyote/1.1 Pragma: no-cache {"errno":0,"data":{"create_time":"2015-09-06 16:00:25","update_at":"2015-09-20 16:58:45","id":"KEY","current_value":"1"},"error":"succ"}
剩下工作就是解析Json数据读取出来数值
原文：http://www.cnblogs.com/Mysterious/p/4823754.html