A Groovy GeoCoder.us Client for Grails

I have a need for a Grails GeoCoder for a project I'm working on. I'm going to feed the GeoCodes to a RichUI front end using Google Maps. And, I'll have access to addresses in the format...
1600 Pennsylvania Ave

Washington, DC 20502

... so I've written a simple front-controller service to take in an address as a string, wash it into the format used by geocoder.us and pass it to geocoder.us then take the result and build a marker for RichUI.

In the grails-app/services directory:

import groovy.net.xmlrpc.*
// Shawn Hartsock sez: don't just use the free service, buy a geocoder.us account!
class GeoCoderService {
boolean transactional = true
static final serviceUrl = "http://geocoder.us/service/xmlrpc"
def geoCode(String address) {
def query = queryClean(address)
def proxy = new XMLRPCServerProxy(serviceUrl)
def result = proxy.geocode(query)
return result

def marker(String address) {
def res = geoCode(address)
if(res) {
def marker = [:]
marker['description'] = address.replaceAll("\n","<br/>")
marker['latitude'] = res['lat']
marker['longitude'] = res['long']
return marker
return null

def queryClean(String string) {
def query = string.replaceAll("\n",",")
query = query.replaceAll(",,",",")
return query

You'll notice I used groovy.net.xmlrpc.* that's not in Grails by default. You'll have to download groovy-xmlrpc-0.3.jar from http://dist.codehaus.org/groovy/jars/ and put the file in your Grails' project's lib directory. If you are using an IDE you'll have to put that new jar file in the build path for your particular IDE so you can test the service.

If you have a class:

class Address {
Long id
Long version

String address1
String address2
String city
String state
String postalCode
String postalRoutingCode

/** please forgive the multi-line string wrapping */
public String toString() {
return """${address1}${(address2)?"\n$address2":''}
${city}, ${state} ${postalCode}${(postalRoutingCode)?'-':''}${postalRoutingCode}"""


... then when you want to add a geocode location complete with a marker to your Grails RichUI project... all you have to do is ... from the controller:

class AddressController {
// reference the service...
GeoCoderService geoCoderService
// and later on ...

def show = {
/* code skipped */
return [
address: address,
markers: [geoCoderService.marker(address.toString())]

/* more code ... skipped for clarity */


... and in the show.gsp put at the top of the file:

<resource:googlemaps key="myGoogleMapsKey" />
NOTE: you'll have to register for a Google Maps key... see: RichUI-GoogleMaps

... and somewhere inside the file:

<g:if test="${markers}">
<div class="mapPane">
<richui:googlemaps markers="${markers}" zoomLevel="7" />

NOTE: I've noticed Internet Explorer can have a hard time with the googlemaps tag in certain cases unless you wrap it in a div block.

And that's it. I highly recommend that you cache query results from geocoder.us to avoid putting too much load on their free service. If you plan on using this on a heavily used site of any kind I highly advise that you buy an account from GeoCoder it's a really fine service and deserves your support.

RichUI is a really nice tool kit to use and deserves some of your time too. Once you have this down you'll be geoCoding and google mapping so much you may have a hard time focusing on other features! Have fun!

EDIT: Check out these Google GeoCoder based posts by Ken Kousen or Justin Spradlin for how to use the Google GeoCoding services instead.