Allow use it when you need to get information about longitude and latitude from a trigger

Get_LatLon_Trigger

/**
 * A google Maps function to get Latitude and Longitude from Goole Maps API
 * @author 	Edgar Yucel Morán Sanchez
 * @version 1.0
 * @date	11/10/2014
 */
public class CL_GoogleMaps_Geolocations {
	

	public CL_GoogleMaps_Geolocations() {}

	Set<Id> id_accounts = new Set<Id>();
	
	/**
	 * 
	 */
	public void initLocation(Account[] accounts){

		System.debug('### Accounts: '+accounts);
		for(Account acc:accounts){
			if(acc.Ubicaci_n__Latitude__s == null){
				id_accounts.add(acc.Id);
			}			
		}

		getLocation(id_accounts);
	}

	@future (callout=true)
	public static void getLocation(Set<Id> setIdAccounts){

		System.debug('### Set cuentas: '+setIdAccounts);
		List<Account> accounts_to_Update =new List<Account>();
		for(Account account:[Select Id,Name,BillingStreet,BillingCity,BillingState,
							BillingPostalCode,BillingCountry 
						    from Account where Id IN:setIdAccounts]){

			String address = '';

	        if (account.BillingStreet != null)
	            address += account.BillingStreet +', ';
	        if (account.BillingCity != null)
	            address += account.BillingCity +', ';
	        if (account.BillingState != null)
	            address += account.BillingState +' ';
	        if (account.BillingPostalCode != null)
	            address += account.BillingPostalCode +', ';
	        if (account.BillingCountry != null)
	            address += account.BillingCountry;
			

			address = EncodingUtil.urlEncode(address, 'UTF-8');

			//Build the callout
			Http h 			= new Http();
        	HttpRequest req = new HttpRequest();
        	req.setEndpoint('http://maps.googleapis.com/maps/api/geocode/json?address='+address+'&sensor=false');
			req.setMethod('GET');
			req.setTimeout(60000);

			try{
				HttpResponse res = h.send(req);
				
				JSONParser parser = JSON.createParser(res.getBody());

				System.debug('### Response: '+res.getBody());

				//Map<Object,List<Object>> mapa =res.getBody();
				
				double lat = null;
            	double lon = null;

            	while (parser.nextToken() != null) {
	                if ((parser.getCurrentToken() == JSONToken.FIELD_NAME) &&
	                    (parser.getText() == 'location')){
	                       parser.nextToken(); // object start
	                       while (parser.nextToken() != JSONToken.END_OBJECT){
	                           String txt = parser.getText();
	                           parser.nextToken();
	                           if (txt == 'lat')
	                               lat = parser.getDoubleValue();
	                           else if (txt == 'lng')
	                               lon = parser.getDoubleValue();
	                       }
	 
	                }
	            }

	            System.debug('LAT: '+lat);
	            System.debug('LON: '+lon);

	            if(lat!=null){
	            	account.Ubicaci_n__Latitude__s = lat;
	            	account.Ubicaci_n__Longitude__s = lon;
	            	update account;
	            }

	            

			}
			catch(Exception er){
				System.debug('### ERROR: '+er.getMessage());
			}

		}
	}
}