Using Google Maps Geocode API with Salesforce Apex

GoogleMapsGeocodeAPI.apex

public class GoogleMapsGeocodeApi {
     
    public string geocode(String address){
        String url = 'https://maps.googleapis.com/maps/api/geocode/json?address='
            + EncodingUtil.urlEncode(address, 'UTF-8')
            + '&components=country:GB'
            + '&key=' + getGoogleMapsAPIKey();
        
        return getHttp(url);
    }
    
    private string getHttp(string url) {
        
        Http h = new Http();
        HttpRequest req = new HttpRequest();
        HttpResponse res = new HttpResponse();
        req.setMethod('GET');
        req.setEndpoint(url);
        req.setTimeout(120000);
        res = h.send(req); 

        return res.getBody();
    }
    
    private string getGoogleMapsAPIKey() {
        return ''; // get key from custom settings
    }
    
}