interface{}读取非常不方便，将其转换成map类型后就可以读取了

#res是个<span class="hljs-keyword">interface</span>{}
res.(map[<span class="hljs-built_in">string</span>]<span class="hljs-keyword">interface</span>{})

参考：http://stackoverflow.com/questions/25214036/getting-invalid-operation-mymaptitle-type-interface-does-not-support-in