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Welcome to the Apache Tuscany SCA User guide. Here you will find information aimed to help you develop SCA components and applications using Tuscany's Java SCA implementation.

This is a work in progress, so please contribute and comment so we can make this valuable to you


Apache Tuscany SCA User Guide

Introduction
Obtaining a Tuscany Java SCA Implementation
Running the Calculator Sample
Running additional samples (this was already here... may need to move out)
Building your own Calculator Application
Building an Application (this was already here... may need to move out)
Using Extensions
 

Introduction">Introduction

Tuscany is based on Service Component Architecture (SCA). SCA is a simple model for creating service-oriented applications. SCA also provides a way to represent services in a variety of languages and a model for associating poicies with services.

Service Oriented Architecture (SOA) is an architectural approach driven by the need to overcome the challenges of tightly coupled and department-specific applications. SOA promises benefits such as improved business agility, improved flexibility, cost reduction, and the easy sharing of information in heterogeneous and distributed environments.

Service Component Architecture (SCA) addresses the complexity of developing an SOA solution through its simple model for creating service-oriented applications for the whole enterprise - from the client to the back-end.

This user guide will use the Calcualater Sample which uses a mix of the Tuscany technologies SCA, SDO and DAS. This sample shows how SCA, SDO and DAS can be combined to create service-oriented applications that implement business scenarios.

Running the Calculator Sample">Running the Calculator Sample

  1.  Download the sample file.
  2.  Unzip it to a local folder such as C:\Temp
  3.  In Eclipse, select File -> Import -> General -> Existing Projects into Workspace
  4.  Click Next.
  5.  Select the Select root directory option and click the "Browse" button to point to C:\Temp.
  6.  Select CalcultorSample directory and click Finish. The project is created.
  7.  Expand the CalcultorSample. Expand "src/main/java/calculator", right-click CalculatorClient.java and select Run as ... --> Java Application. You will see   the following output in the console view:

3 + 2=5.0
3 - 2=1.0
3 * 2=6.0
3 / 2=1.5

Building your own Calculator Application">Building your own Calculator Application

Topics to include?

Creating Java SCA Components
Create a client to invoke the service.
Packaging a Standalone Tuscany Application?
Building a Tuscany Web Application?

Components">Components

Compents are the building blocks for creating SOA Applications. They contain the information that defines the program logic or implementation (component implementation), how the component interacts with other components (component type) and defines how it fits in with the other parts of the soluion (composition/assembly).

  • A service header file that defines the operations that can be invoked on the component
  • An implementation header file that defines the implementation and extends the service header file
  • A C++ implementation of the service that implements the operations defined in the service header file
  • Proxy and wrapper header and implementation files generated by the Tuscany C++ SCAGEN tool
  • A service definition in a .componentType file
  • An SCDL component definition within an SCDL composite file. Usually this composite file will contain multiple components configured and assembled together.

Service Component Descritpion Language (SCDL)">Service Component Descritpion Language (SCDL)

Create a client to invoke the service.">Create a client to invoke the service.

  1. Create a file and name it CalculatorClient.java 

Your component, composite and subsystem are now ready to be invoked. Create a client that will call the service. E.g. the Calculator client (in the CalculatorClient.cpp file) contains code similar to the following:

package calculator;

import org.apache.tuscany.api.SCAContainer;
import org.osoa.sca.CompositeContext;
import org.osoa.sca.CurrentCompositeContext;

/**

  • This client program shows how to create an SCA runtime, start it,
  • locate the Calculator service and invoke it.
    */
    public class CalculatorClient
    Unknown macro: {public static void main(String[] args) throws Exception{ SCAContainer.start("Calculator.composite"); CompositeContext context = CurrentCompositeContext.getContext(); CalculatorService calculatorService = context.locateService(CalculatorService.class, "CalculatorServiceComponent"); // Calculate System.out.println("3 + 2=" + calculatorService.add(3, 2)); System.out.println("3 - 2=" + calculatorService.subtract(3, 2)); System.out.println("3 * 2=" + calculatorService.multiply(3, 2)); System.out.println("3 / 2=" + calculatorService.divide(3, 2)); SCAContainer.stop(); }
    }

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