This document is the development guideline for SCA Java 2.x project.
OSGi Overview and ApproachGeneral GuideWelcome to the Tuscany SCA Java subproject project. We look forward to your participation and try to help you get on board. Feel free to ask your questions on the mailing list. Here are some general guidelines we use in this project.
PrerequisitesJava SCA requires the following:
Checking out code from SubversionUse the command as follows: svn checkout https://svn.apache.org/repos/asf/tuscany/sca-java-2.x/trunk/ Setting up your Development Environmenttop-down build (recommended approach)Check out all of the java source code. svn checkout https://svn.apache.org/repos/asf/tuscany/sca-java-2.x/trunk/ Building the SCA source code : mvn -fae clean install It should work even if you start with an empty Maven local repository, and it should always work, however when you are building for Tuscany for the first time there are a lot of dependencies which must be downloaded so the first build can take a long time and it may fail with problems retrieving the dependencies.
The SCA build consumes a good amount of memory, in case you are seeing issues during the build, set a MAVEN_OPTS environment variable to allocate more memory for the build process. Windows : SET MAVEN_OPTS="-Xmx512m -XX:MaxPermSize=384m" Importing SCA modules into your Development IDEUsing EclipseIf this is the first time you are using your workspace with maven m2 local repository, you will need to tell your Eclipse workspace the location of the directory, and you can do this with the following command : mvn -Declipse.workspace=[path-to-eclipse-workspace] eclipse:add-maven-repo In order to generate the necessary project files to import the SCA modules to Eclipse, you can use the maven eclipse plugin mvn eclipse:eclipse To help with development in an OSGi environment Tuscany also has a build profile to setup the Eclipse Plugin Development Environment: mvn -fae -Peclipse Now set the "Target Platform" in your Eclipse IDE by following the steps below :
Then as when using eclipse:eclipse launch your Eclipse IDE, select File->Import->Existing projects into Workplace, and then import the project from SCA Modules into your Eclipse Workspace. There are also some Tuscany Eclipse code templates available: Eclipse Build TroubleshootingSometimes a Maven build will work from the command line, yet the same component will not build in the Eclipse environment. Of course, developers try to prevent this from happening, but it does happen and makes for a valid Jira. In the meantime, here are some steps that might help correct build issues in the Eclipse environment:
Coding GuidelinesThere are a few simple guidelines when developing for JAVA SCA:
While Tuscany does not yet have an official style or template, here are some templates that folks have been using and have been checked into the build which are stored at https://svn.apache.org/repos/asf/tuscany/java/etc/ Naming conventions to increase consistencyFolder Names: Please use all lowercases and dashes in folder names (like in the jar names)
Package names: Package names within modules should include the module name so that source code can be located in the source tree easily. So, for example, java/sca/module/implementation-java would be in package structure org.apache.tuscany.implementation.java.* TestingTuscany uses plain junit test cases to perform unit and integration testing, below is an example that can also be used as a template for writing new test cases; it demonstrates how to bootstrap the Tuscany SCA runtime in your test case, and because they are based on junit, you can run it from your IDE of choice or from Maven. Note that we are using JUnit 4.2 code style in OSGI development stream /** * Description of your test case and necessary details you find necessary */ @Scope("COMPOSITE") @EagerInit public class CalculatorTestCase { private static CalculatorService calculatorService; private static NodeLauncher launcher; private static Node node; @Reference public void setCalculatorService(CalculatorService calculatorService) { CalculatorTestCase.calculatorService = calculatorService; } @BeforeClass public static void setUpBeforeClass() throws Exception { launcher = NodeLauncher.newInstance(); String location = ContributionLocationHelper.getContributionLocation(CalculatorClient.class); node = launcher.createNode("Calculator.composite", new Contribution("test", location)); System.out.println("SCA Node API ClassLoader: " + node.getClass().getClassLoader()); node.start(); } @AfterClass public static void tearDownAfterClass() throws Exception { if (node != null) { node.stop(); node.destroy(); } if (launcher != null) { launcher.destroy(); } } @Test public void testCalculator() throws Exception { // Calculate assertEquals(calculatorService.add(3, 2), 5.0); assertEquals(calculatorService.subtract(3, 2), 1.0); assertEquals(calculatorService.multiply(3, 2), 6.0); assertEquals(calculatorService.divide(3, 2), 1.5); } }
Client Applications as SCA ComponentsBelow is how you can build client applications as an SCA component. @Scope("COMPOSITE") @EagerInit public class CalculatorClient { private CalculatorService calculatorService; @Reference public void setCalculatorService(CalculatorService calculatorService) { this.calculatorService = calculatorService; } @Init public void calculate() { // Calculate System.out.println("SCA API ClassLoader: " + print(Reference.class.getClassLoader())); 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)); } private static String print(ClassLoader cl) { StringBuffer buf = new StringBuffer(); for (; cl != null;) { buf.append(cl.toString()); buf.append(' '); cl = cl.getParent(); } return buf.toString(); } } Maven Build StructureWe use the term Module to refer to the leaf of maven tree.
Adding a new module and not ready to integrate?'work-in-progress' modules can be worked on in the same source tree and yet not break the top-down build. You can do this by not listing your module(s) in java/sca/modules/pom.xml. Development HintsGenerating Eclipse WTP Web Projects for Webapp samplesIf you're using Eclipse WTP and want to get WTP Web Projects generated The magic -Dwtpversion=1.5 option will add the WTP Web project nature to h3: Generating Dependencies for Ant in Samples Figuring out the package dependency to include in Ant build.xml can be a pain. Here is a quick jar tvf sample-feed-aggregator-webapp.war | grep .jar | awk '{ printf "%s\n", $8 }' | sed -e "s/WEB-INF\/lib\///" | awk '{ printf "<include name=\"%s\"/>\n", $1 }' | grep -v tuscany |