Using GroovyWS with the TerraService (Part 1)

I got recently a post on the difficulty of retrieving complex elements by some webservices, I will try to clarify some issues on this in this post using the Microsoft Terra webservice.
The TerraService is an WebService API which allows you to query the Microsoft TerraServer database of high resolution aerial imagery. Among other things, you can:

• Find Geographic and Image Coordinates by Place Name
• Convert coordinates from one projection system to another
• Fetch tile meta-data and image-data

Today, I will just concentrate on using the search API to show how to deal with arrays with GroovyWS.

If you look at the TerraService WSDL you will notice that some functions return arrays. This is clear from the following part of the WSDL:

<s:element name="GetPlaceList">
 <s:complexType>
   <s:sequence>
     <s:element minOccurs="0" maxOccurs="1" name="placeName" type="s:string"/>
     <s:element minOccurs="1" maxOccurs="1" name="MaxItems" type="s:int"/>
     <s:element minOccurs="1" maxOccurs="1" name="imagePresence" type="s:boolean"/>
   </s:sequence>
 </s:complexType>
</s:element>

<s:element name="GetPlaceListResponse">
 <s:complexType>
   <s:sequence>
     <s:element minOccurs="0" maxOccurs="1" name="GetPlaceListResult" type="tns:ArrayOfPlaceFacts"/>
   </s:sequence>
 </s:complexType>
</s:element>
<s:complexType name="ArrayOfPlaceFacts">
 <s:sequence>
   <s:element minOccurs="0" maxOccurs="unbounded" name="PlaceFacts" type="tns:PlaceFacts"/>
 </s:sequence>
</s:complexType>

<wsdl:message name="GetPlaceListSoapIn">
 <wsdl:part name="parameters" element="tns:GetPlaceList"/>
</wsdl:message>
<wsdl:message name="GetPlaceListSoapOut">
 <wsdl:part name="parameters" element="tns:GetPlaceListResponse"/>
</wsdl:message>

<wsdl:operation name="GetPlaceList">
 <wsdl:input message="tns:GetPlaceListSoapIn"/>
 <wsdl:output message="tns:GetPlaceListSoapOut">
</wsdl:operation>

Therefore, the following call to GetPlaceList will return an object embedding an array of PlaceFacts.

def proxy = new WSClient("http://terraservice.net/TerraService.asmx?WSDL", this.class.classLoader)
def plist = proxy.GetPlaceList("mountain view", 5, true)

From this object, one can call getPlaceFacts to get the array. Here we asked for its size:

println plist.placeFacts.size()

Then one call go through all the places returned by the call to the TerraService:

for (pfact in plist.placeFacts) {
  println pfact.place.city
  println pfact.place.state
}

All this might look a bit cryptic, and it is probably. The fact is that there is no magic. When you want to call a remote service, you have to know its signature. If you don't have any manual then you have to read and understand the WSDL which represents the contract you are offered.

If you have any idea on how thing could be improved by GroovyWS for helping you in writing your scripts then do not hesitate to give your feedback.

GroowyWS 0.2.0

It has been a long time since I talked about GroovyWS ... Groovy has been out for a week now and I have been working a bit on GroovyWS as well so I decided to push a new version. The changes brought by this new version are minor in term of workload but they should (hopefully) made GroovyWS more usuable in a production environment.
The first change deals with https support. Now you cab use the WSClient with a serving using secure http. This has been tested using Amazon S3 web services:

def proxy = new WSClient("https://s3.amazonaws.com/doc/2006-03-01/AmazonS3.wsdl",..)

You can now create buckets :-)

The other major change is the support for servers using basic authentication. So if your server requests to have an "Authorization: Basic bG9naW46cGFzc3dk" header in the request, you are able to set the correct properties using:

System.props["http.user"] = "login"
System.props["http.password"] = "passwd"

Do not forget that the token transmitted is just a base64 encoding of "login:passwd", so basically your are transmitting your credentials in clear text :-). You don't trust me ? Try this:

echo -n 'login:passwd' | openssl enc -a -e

or

echo 'bG9naW46cGFzc3dk' | openssl enc -a -d

Only use this over https !

The last minor change is to publish the SOAPAction property in the WSDL generated by the server. This makes odd commercial products work with WSServer !

What are the next steps ? I would like to add WS-Security support. This is something I already have partially, I am missing a public server to test it and would like to know how you would envisage its usage using groovy. So if you have any idea, do not hesitate to contact me ...

GroovySOAP is now GroovyWS

It has been a long time without news. The fact is that I have been moving from France to Singapore and that keeps me busy with and away from the keyboard. Anyway I am back. You probably now that CXF has taken over XFire. Thanks to the work done by Dan & Al, the move has been pretty fast and we now have the best from XFire & Celtix.
I thought it was time to move also from GroovySOAP (relying on XFire) to GroovyWS (build on top of CXF). What are the difference so far ? If you choose GroovyWS you will have to use Java5 but you will gain an easiest way to build your clients (no worries about the complex types, they are automatically generated) and a proxy support.
In the future, I will probably start to work on basic authentication as this has been asked several times.
The build can be found here.