MoSeS - Moby Services Support

The current Moses is for Java services - but not much is missing and Moses can produce also code in Perl (if you think that it would be useful let me know).

MoSeS Components

The Moses consists of four major parts:

• Code Generators
  • Data types generator
  • Service skeletons generator

• Biomoby XML Parser and associated general data types for storage

• Support on the client side, and
  • Base client
  • Base command-line client

• Support for service deployment

Overview

This is an example of a full implementation of a service called HelloBiomobyWorld that does not expect any input and produce a String data type (with a predictable contents) (the code is available in jMoby):

package org.jmoby.tutorial.service;

import net.jmoby.samples.HelloBiomobyWorldSkel;
import org.biomoby.shared.MobyException;
import org.biomoby.shared.parser.MobyPackage;
import org.biomoby.shared.parser.MobyJob;
import org.biomoby.shared.datatypes.*;

public class HelloBiomobyWorldImpl
    extends HelloBiomobyWorldSkel {

    public void processIt (MobyJob request,
			   MobyJob response,
			   MobyPackage outputContext)
	throws MobyException {
	set_greeting (response, new MobyString ("Hello, World!"));
    }
}

The service was registered in a Biomoby registry as follows:

<Services>
  <Service authURI='samples.jmoby.net'
    serviceName='HelloBiomobyWorld'
    lsid='urn:lsid:biomoby.org:serviceinstance:samples.jmoby.net,HelloBiomobyWorld'>
    <serviceType>Retrieval</serviceType>
    <authoritative>1</authoritative>
    <Category>moby</Category>
    <Description>
This is a cult service, known to an exclusive group of persons sharing an esoteric
interest. One of their believes is that a word started on January, 1 1970.
    </Description>
    <contactEmail>martin.senger@gmail.com</contactEmail>
    <signatureURL></signatureURL>
    <URL>http://localhost:8080/axis/services/</URL>
    <Input>
    </Input>
    <Output>
      <Simple articleName='greeting'>
        <objectType>String</objectType>
      </Simple>
    </Output>
    <secondaryArticles>
    </secondaryArticles>
  </Service>
</Services>

The same happens also with data types name, as shown in the second example (here it shows only part of the implementation class but its full version is in jMoby):

    /**************************************************************************
     * This is a mandatory method to be implemented.
     *************************************************************************/
    public void processIt (MobyJob request,
			   MobyJob response,
			   MobyPackage outputContext)
	throws MobyException {
 	Regex input = get_language (request);
	if (input == null) return;

 	simple_key_value_pair[] output = doBusiness (input);
 	set_helloSet (response, output) ;
    }

    /**************************************************************************
     * Here is where the bussines logic is done
     *************************************************************************/
    protected simple_key_value_pair[] doBusiness (Regex regex)
	throws MobyException {

	String regExpression = regex.get_regex();
	if (isEmpty (regExpression))
	    return new simple_key_value_pair[] {};
        ...

The Regex and simple_key_value_pair are Biomoby data types - and you see that you can manipulate them as any Java object. The other highlighted words are parts of methods - they came either from the article names or from data types names (where article names were missing). The suffix Set in one method indicates that the object will be a Biomoby collection.

Quick start

1. Register your service (for example, a service named TheService). Select what data types it will consume and what data types it will produce. Register the unless they are already registered. (There is no support in Moses for this step - there are already several ways how to do it by other tools.)

2. Generate Java classes for all data types, compile them, packed them into a jar file and let javadoc generate their API documentation (note that you must have Internet connection because it explores Biomoby registry):

   ant moses-datatypes
   

3. Generate skeleton for your service, compile it, generate its API:

   ant -Dmoses.service=TheService moses-services
   

4. Write your own implementation, for example a class TheServiceImpl, that extends skeleton TheServiveSkel, and that contains the business logic you want to have. Compile it, test it (you can test it using the BaseCmdLineClient even before you deploy it to your Tomcat). If you place your source code into src/samples - use whatever package you like - you can compile it using jMoby Ant:

   ant
   

5. Start your Tomcat and deploy your implementation to your Tomcat (sorry, this is not yet fully implemented):

   ant -Dservice.name=TheService deploy-services
   

Main features

• They parse data input in Biomoby XML and they produce data in Biomoby XML format.
• They accept and deal with any number of Biomoby jobs in one request (a job is what Biomoby API calls a query, and what is expressed inside one mobyData Biomoby XML).
• They can accept XML data as string or as a byte array - as required by the Biomoby API.
• They are prepared to accept more specialized data types that they were registered for. This data type can be either an existing data type in time where the service skeleton was generated, but it can be also a new data type that was added to Biomoby data types long after the code for the service was generated.
• The source code of service skeletons contains information about the service (taken from the registry), including graphs of service neighbourhood (other services that can be connected with this one). Here is an example extract from service API:

  

• It has built-in access to the deployment parameters (the parameters that can give service necessary configuration properties, such as JDBC user name and password).

Some other features are either planned to be added, or to be discussed how useful they would be, some of them can be done by few lines of code:

• Providing own testing data.
• Providing additional, Biomoby non-compliant methods, such as ping.
• Connecting automatically to a monitoring service, such as Bionanny.
• Supporting automatic data compression (without breaking clients that do no support it).