I would like to store a user enter location and could do with some pointers on how to go about it.
Input - I wish to allow the user to enter a location using either a map (eg Google maps) or text input.
Storage - I believe it would make sense to store the location as the longitude and latitude.
Manipulation and Display - I'd like to display a name for a given longitude and latitude. I'd also like to search for all inputs from an arbitrary region eg London.
What libraries or packages (preferably Java, preferably free) can be used to help with this process?
The process of converting an address to a latitude/longitude pair is called geocoding. Doing the reverse process (lat/long to address) is called reverse geocoding.
The Google Maps API is capable of performing both these functions. However, note that there are service limits in place on the number and frequency of requests made to perform these functions. This means you'll want to implement some kind of caching mechanism for the results.
Doing a name search for a region I don't know about. The maps API may do this, but I haven't gone in enough depth with it to find out.
Related
My application should allow users to store events and their locations and then perform search on them - so I need those locations in my database with their names and latitudes/longitudes. Google API doesnt allow storing anything else but place IDs so I have to find something else that can autocomplete/suggest places on UI and allow storing it my database.
Does anyone know such a good service?
You can simply add your points in your DB based on each point Lat & Long values. So when user is searching somewhere you have his current location(Lat-Long), Therefore you can search in your DB and get the distance of each saved point with current location and retrieve the results you want to show (i.e in JSON format).
In client-side use some auto-complete jquery library to show the nearby places and somethings like that (with additional information).
Google Map API has a service that you can show some custom marker on the map with your custom configuration like marker icon, description and etc. You can show your additional information in description as HTML format.
You can see some example here:
Customizing a Google Map: Custom Markers
Hope these tips would be helpfull. Regards.
Suddenly I've found an answer that helps me:
https://productforums.google.com/forum/#!topic/maps/hNc1OOU6Zm8
So I can use some Google's data under some conditions.
I have been searching for some information on what I want to achieve but not getting any clear answers.
I have a database with thousands of addresses. I want that when the user searches by entering a postcode, the search should show all the available addresses close to the postcode in a map. Zooming In would obviously show closer address to the search postcode (and hence less search results) and zooming out would also include farther addresses (and hence more search results). And then clicking the location icon would display the complete address.
Do I need to store the addresses as longitude and latitude or google map can search a location using postcode? If I need to store the longitude and latitude then whats the best way to convert an address to long and lat?
I really appreciate if you can point me to any useful links or reusable code.
Thanks
As I understand it, you want to find all closest locations from YOUR data to some location, which is identified by a postcode.
First, you have to convert all your addresses to coordinates (Latitude and Longitude). You can do that using Google Geocode API, you will have to create as script, which calls Google Geocode API for every single address in your db:
https://maps.googleapis.com/maps/api/geocode/json?address=EXAMPLE_ADDRES&key=YOUR_API_KEY
The response this script brings you is documented here. You can parse it to get latitude and longitude for each locations and store them in your database. BEWARE of limitations of the Google Geocode API. They are listed here. You have to create your script in a way that won't exceed those limits. Also read this article for caching the results of geocoding, to make sure you don't violate the terms of service. The article also contains some best practices and examples of server side geocoding.
Now, when somebody inputs postcode to your application, you can use the geocoding API or Google maps Geocoding service to translate postcode to coordinate and using haversine formula you can calculate the closest locations from your db, to coordinates of the postcode location. You can do that on frontend side, example in this SO answer (instead of address you will input postcode + state/country in the address bar) or on backend side, if you use MySQL check this SO question.
I am creating links to Google Maps for a large number of locations using this URL pattern:
https://www.google.com/maps?q=[query]
In many cases, Google knows that the particular business exists at that location. In those cases, I want to include the place/business name in the query so the resulting map shows additional information about the business (e.g. name, phone numbers, site URL, office hours, etc.). For example:
https://maps.google.com/?q=Child+Guidance+Center,+Inc.+525+Cabrillo+Park+Dr+#300+Santa+Ana,+CA+92701
But, if the place isn't known, including the business name in the query prevents the map from adding a marker to the correct address. For example:
https://maps.google.com/?q=Awesome+Paint+527+Cabrillo+Park+Dr+Santa+Ana,+CA+92701
It can cause the map to be totally zoomed out, or focus on a competing business with a somewhat similar name in the same general area.
How can I make this work better? I would like the map pin to always go in the correct location for the address I specify. If the business name I provide is known to Google at that address, then I'd like the nice panel of extra information. If it is not known, I just want the pin.
Thank you.
This similar question is asking about creating embedded maps, which is a slightly different case Google map to show name of location if found, otherwise just the address. I'd prefer to avoid extensive use of the APIs because I'm worried about exceeding the free limit, but more generally geocoding the address that worked above (Child+Guidance+Center,+Inc.+525+Cabrillo+Park+Dr+#300+Santa+Ana,+CA+92701) returns zero results like so:
http://maps.googleapis.com/maps/api/geocode/json?address=Child+Guidance+Center,+Inc.+525+Cabrillo+Park+Dr+#300+Santa+Ana,+CA+92701
I have a Google spreadsheet with one column of physical addresses, and I want to have a second column be the time in minutes to walk between the address in column 1 and a second address (as determined by Google Maps). Any recommendations on how to accomplish this task?
From my understanding of the Google Maps terms of service, they:
don't like people using their service as a "batch geocoder". This means that
you will need to throttle your requests (place delays between each successive request, to avoid the OVER_QUERY_LIMIT error)
it is against the terms of service to use the geocoder (and maybe the distance service) without displaying a map graphic
If you still want to proceed,
you need some way of extracting the address from your spreadsheet. I think there's a Google docs API that will help you do that. I also found some custom Javascript code that does that for you easily. I don't have a link anymore :(
once you have the addresses readable from the Google Maps Javascript API, you can call the distance or directions API to get the walking distance
then you need to save that back to the spreadsheet.
It sounds like a possible application for the Distance Matrix Service.
But you can only use it if you will be displaying a map
Use of the Distance Matrix API must relate to the display of
information on a Google Map; for example, to determine
origin-destination pairs that fall within a specific driving time from
one another, before requesting and displaying those destinations on a
map. Use of the service in an application that doesn't display a
Google map is prohibited.
It is easy to use the Google Maps API to find a specific street address and return the latitude and longitude. For example, link.
However, it appears that typing in the name of a specific location, for example a park, causes problems. Often these don't have a specific street number (at least, not easily findable). Despite the fact that Cadigal Reserve is located at the same address as in the link above, if I enter that as part of the query string and remove the street number, the results become rather useless: link
Typing this directly into maps.google.com easily finds the park itself (and of course, you could then find the latitude/longitude by looking in the URL).
Is there not any way of using the Google Maps API to geocode a park location like this?
It is important to understand that geocoding is not an exact science. The recommended practice if you have addresses that you know should geocode to a specific location is to build a cache and use local (client-side) geocoding.
In version 2 of the api you would build your own client-side cache that contains pre-computed geocoder responses by extending the GeocodeCache. Once a cache is defined, you would call the setCache() method and away you go. This is pretty much explained here:
http://code.google.com/apis/maps/documentation/javascript/v2/services.html#Geocoding_Caching
However, AFAIK GeocodeCache was removed in V3 of the api...
So, I would suggest implementing your own client -side caching-strategy of known addresses and their corresponding coordinates. When your application receives a geocode request for a known address the response would come from your cache (rather than Google's geocoding servers).
Failing all that you can always use a payed geocoding service that, in theory, will have a much more accurate dataset (as well as a higher limit on requests, etc).
Finally, you should also take a look through the Geocoding Strategies document as it gives a good handle on some of the issues here.