Tuscany Calculator-Combo - A Simple SCA Assembly involving Java, JavaScript, Ruby, RMI and WebServices

Overview

The objective of this sample is to provide simple demonstration of an SCA application assembly involving different implementation and binding technlogies.
This sample is an SCA Standalone Calculator Application called "Calculator Combo" assembling Calculator functions implemented in Java, JavaScript and Ruby and references to the external RMI and WebService implementations of the Calculator funtions. Besides, this assembly also includes a component that is implemented as a Composite and there is also a simple demonstration of property configuration of components.

This sample depends on two other samples which are :-
i) The CalculatorRmiService SCA Standalone Assembly which assembles Calculator functions implemented in Java and exposing the Calculator as RMI Services
ii) The Calculator WebService that assembles Calculator functions implemented in Java and exposing them as WebServices

Location

The source for this sample is located  in the paths - samples\standalone\calculator-combo of the source distribution.

If there is binary distribution available for these samples, then you may find these samples packaged as sample-calculator-combo.jar.

Building & Running the Calculator-Combo Sample Source

If you are working with a source distribution, then you must first build the source of this sample.
- Ensure that you have Java 5 installed on your system.
- Next, you must have Maven 2.0.4 installed on your system. Look up http://maven.apache.org/download.html for downloading and installing Maven.

Building the Calculator-Combo Sample

Having installed Maven, open a command line console and switch over to the directory on your local system, where you have extracted the source.
- Now switch futher into the subdirectory samples\standalone\calcualtor-combo. Within this directory execute the following command
> mvn
This will build the calculator-combo sample, package a JAR file for the composite and make it available in the sub-directory samples\standalone\calculator-combo/target


Setting up Tuscany Standalone Runtime

To run these samples you need the Tuscany Standalone Runtime. This is available as a distribution that can be conveniently unpacked and setup in the samples directory itself. For this, do the following: -

i) From the directory samples\standalone\calculator-combo execute the following command
> mvn dependency:unpack
This will unpack the Tuscany Standalone Runtime Distribution to the target\distribution sub-directory within the present working directory - samples\standalone\calculator-combo
ii) This sample would require the following extensions of Tuscany : -
RMI Binding Extension, JavaSCript Container Extension, Axis2 Binding Extension, Ruby Container Extension.
The jar files of all of these extensions have to copied from the the contrib sub-directory into the extensions directory of the distribution. ie. execute the following from the samples\standalone\calculator-combo sub-directory: -
> copy target\distribution\contrib\rmi-1.0-incubator-M2.jar target\distribution\extensions\rmi-1.0-incubator-M2.jar
>copy target\distribution\contrib\axis2-1.0-incubator-M2.jar target\distribution\extensions\axis2-1.0-incubator-M2.jar
>copy target\distribution\contrib\javascript-1.0-incubator-M2.jar target\distribution\extensions\javascript-1.0-incubator-M2.jar
>copy target\distribution\contrib\ruby-1.0-incubator-M2.jar target\distribution\extensions\ruby-1.0-incubator-M2.jar
> copy target\distribution\contrib\databinding-sdo-1.0-incubator-M2.jar target\distribution\extensions\databinding-sdo-1.0-incubator-M2.jar
Note : If you are working with SNAPSHOTs versions of Tuscany Extensions then the files in the above commands must be substituted with the corresponding SNAPSHOT versions. For example rmi-1.0-incubator-M2.jar in the above command must be substituted with rmi-1.0-incubator-M2-SNAPSHOT.jar

Running the Calculator-Combo Sample

Now that the sample source has been built and the Tuscany Standalone Runtime setup, you may run the Calculator-Combo sample as follows: -

i) Ensure that the Calculator-RMIService Sample and the Calculator WebService samples are running. You can find them under samples\standalone\calcualtorRMIService and samples\webapp\calcualtorws directories of the samples source distribution respectively. Details pertaining to building and running these samples can be found in the respective readme.html files under each of them.
ii)Switch to the samples\standalone\calculator-combo\target\distribution sub-directory and execute the following command:
> java -jar bin\launcher.jar ..\sample-calculator-combo.jar
iii) You will initially observe messages that relate to resolution of dependencies required to run this sample and finlly see the following message on your console
***************************************
Starting the Calculator Combo sample!!!
***************************************
Invoking Java Implementation ...
3 + 2 = 5.0
Invoking Ruby Implementation ...
3 - 2 = 1.0
Invoking over RMI Reference...
3 * 2 = 6.0
Invoking WebService Implementation ...
3 / 2 = 1.5
Invoking Scientific Calculator Composite Implementation ...
.....Invoking Java Implementation ...
.....Average of 1,2,3,4,5,6,7,8,9 = 5.0
.....Invoking JavaScript Implementation ...
.....Square Root of 81 = 9.0
.....Invoking Java Implementation configued for Property ...
.....Sine 90 Degrees = 1.0
.....Cos 90 Degrees = 6.123233995736766E-17
.....Tan 90 Degrees = 1.633123935319537E16

Thus we see the Calculator Combo demonstrating the assembly of different technologies to provide a wholesome Calculator Service to the external world.

Code Overview

The source files are physically organized as shown below:

Calculator Combo
+---main
    +---java
    |   +---calculator
               <Interfaces and Implementations for Calculator Functions>

            +---client
                   CalculatorClient.java
    +---resources
        +---wsdl
               calculator.wsdl
    +---webapp
        +---WEB-INF
               default.scdl
               web.xml


Calculator Combo Sample (Standalone Deployment)

default.scdl - Defines an assembly of calculator functions implemented in Java and exposed as a WebService using the Axis2 binding.
- Defines a SciCalculatorComponent that is implemented by an SCA Composite defined in sci_calc.scdl
sci_calc.scdl - Defines an assembley of advanced calculator functions implemented in Java
- Uses a property configuration called 'trig-metric' that configures the metric that is used when invoking trignometric functions (sin, cos, tan)
AddService.java
AddServiceImpl.java
DivideService.java
MathService.java
MathServiceImpl.java
MultiplyService.java
MultiplyServiceImpl.java
SubtractService.java
SubtractServiceImpl.java		 Java Interfaces and Java Implementations for various calculator functions.
CalculatorService.java
CalculatorServiceImpl.java		 - Defines the coarse grained Calculator Interface and Implementation. This calculator implementation delegates function requests to other granular implemenations listed above.
- Holds a reference to the RMI Calculator Service which is invoked to provide the 'multiply' function
DivideServiceImpl.java - Provides an implementation for the DivideService and is called by the CalculatorService to provide the 'divide' function
- Holds a reference to the Calculator WebService which is invoked to provide the 'divide' function.
SciCalculatorService
SciCalculatorService 		Java Interface and Implementation for advanced functions of the calculator (avg, sqrt, sin, cos, tan, ...)
SqrtService.java Provides an interface defintion for the JavaScript ComponentType definition of the square-root service
calculator.wsdl - Defines the Calculator service using WSDL to enable the CalculatorServiceImpl to be exposed as a Axis2 WebService
- This wsdl is required to establish the client binding to the Calculator WebService
Sqrt.componentType Provides the component type information (component type sidefile) for the JavaScript implementation of the Square-Root service
Sqrt.js A JavaScript implementation for the square-root function
SubtractImpl.componentType Provides the component type information (component type sidefile) for the Ruby implementation of the Subtract service
SubtractImpl.rb A Ruby implementation for the Subtract function