1.5.7 查询文档

请求：GET http://127.0.0.1:9200/secisland/secilog/1/

返回值：

{
  "_index": "secisland"， 
  "_type": "secilog"， 
  "_id": "1"， 
  "_version": 2， 
  "found": true， 
  "_source": {
    "computer": "secisland"， 
    "message": "secisland is an security computer. It provides log analysis products !"
    }
}