Problem Definition

Are you considering integrating a bunch of web services together but may not feel too comfortable with the vulnerabilities of a mash-up approach, the overhead of setting up and using an ESB, or writing a bunch of mind numbing spilling crushing service transformation code? If thats what you want then, yeah sure that would work for a problem definition.

How does it do it?

The java:axis2 plugin (an appcelerator plugin) installs an appcelerator command that can be run either silently or prompt for input to generate and build axis2 stubs from your WSDL url. Once the stubs have been built, the command then creates a java appceleator-based class with services for each corresponding soap endpoint. The solution makes use of code generation so that you may enhace the services should you so desire. Serialization is also taken care of by transforming to/from the JSON model to the Axis2 model so that making the changes to the service mapping is clean and simple.

How would 1 set it up?

Before you can use the plugin, you need to download axis2 and setup your path appropriately. Its pretty easy, just extract axis2 and set your AXIS2_HOME environment variable. Now you can add the plugin to your java project (named $PROJECT):

app install:plugin java:axis2
cd $PROJECT
app add:plugin java:axis2

How do I use it?

Now that you’ve added the plugin, you can now implement the service orchestration for invoking a SOAP endpoint. Lets assume that your wsdl is at http://localhost:8080/axis/services/QueryPort?wsdl. This is how it would flow for you in prompted mode

app gen:axis2
Whats the url for your wsdl?
http://LODVM1044:8080/axis/services/QueryPort?wsdl
What directory do you want to use for storing the axis stubs? [src/axissource]
src/axissource/queryport
What package name do you want to use for your axis stubs? [my.axis]
queryport.axis
What directory do you want to generate the services to? [app/services]
app/services
What package name do you want to use for your appcelerator services? [my.service]
queryport

Alternatively you could run this silently:

app gen:axis2 --axisdir=src/axissource/queryport --axispackage=queryport.axis \
--wsdl=http://localhost:8080/axis/services/QueryPort?wsdl --silent=true --appcpackage=queryport

Here is a sample snippet of the code that will be generated to map your appcelerator services to a web service call:

package cmdb.service;
 
import org.appcelerator.annotation.Service;
import org.appcelerator.messaging.Message;
 
public class QueryService {
 
	@Service(request = "graphQuery.request", response = "graphQuery.response")
	public void graphQuery(Message request, Message response) throws Exception {
		uery param = (axis.query.QueryServiceStub$Query) AxisUtil.toAxisObject(request, axis.query.QueryServiceStub$Query.class, "param");
		axis.query.QueryServiceStub$QueryResult result = new axis.query.QueryServiceStub().graphQuery(param);
		response.getData().put("result",AxisUtil.toMessageDataObject(result));
	}
}

Note that for this to work you will have to upgrade your Appcelerator installer to 1.1.20+ (next release to be out shortly), I’ve updated mine off of the svn trunk. To check your installer:

app --version

Some more details on how to test

Now the question is, how do i know how to construct my request parameters? You can use the AxisUtil class to help you out, here is a sample snippet for my parameter into the web service, the model class Query:

Query param = createQuery(); //however you want to create your model object
System.out.println(AxisUtil.toJSONObject(param).toString());

the request body will directly reflect that ex:

{"query":{"itemTemplate":[{"contentSelector":null,"id":{"value":"ALL_CI1s"},
 
 
 
 
"instanceIdConstraint":null,"recordConstraint":[],"suppressFromResult":false,
"xpathExpression":[]},{"contentSelector":null,"id":{"value":"ALL_CI2s"},"instanceIdConstraint":null,
"recordConstraint":[],"suppressFromResult":false,"xpathExpression":[]}],
"relationshipTemplate":[{"contentSelector":null,"depthLimit":null,
"id":{"value":"ALL_Relations"},"instanceIdConstraint":null,"recordConstraint":[],
"sourceTemplate":{"maximum":22,"minimum":0,"ref":{"value":"ALL_CI1s"}},
"suppressFromResult":false,"targetTemplate":{"maximum":0,"minimum":0,"ref":{"value":"ALL_CI2s"}},
"xpathExpression":[]}]}}

This utility will help you to see how the data is structured. For a more detailed example unit test check out SerializationTest.java

Wrap Up
In this post we demonstrated:

• what the plugin does and the problems it solves
• how to set it up and use it, as well as how to test

this blog cross-posted at http://www.appcelerant.com/java_axis2.html

Technorati Tags: appcelerator, axis2, java, ria, soap