I am new to GIS . I hava a folder it include a .mxd file and a .gdb folder, the .gdb folder hava many .gdbtable and .gdbindexes files etc, it's a road network data of a city. Now, I want to know which road it belongs to for a given latitude and longitude, which software or sdk should I use? is there have a similar open source project?
You can use Spatial Join (Analysis) to join the information of the nearest road to your point (lat/long).
It will create another field in your point layer that belongs to the name of the nearest road.
Near (Analysis) can be used to find the nearest line feature to each point feature. The tool will create a new field called 'NEAR_FID' in the point feature attribute table which holds the identifier of the nearest line. A distance field is also created if this of use to you.
This tool is available in ArcGIS for Desktop with an ADVANCED license level only.