Space: Apache Tuscany (https://cwiki.apache.org/confluence/display/TUSCANY)
Page: SCA Java Development Guide
(https://cwiki.apache.org/confluence/display/TUSCANY/SCA+Java+Development+Guide)
Edited by Luciano Resende:
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{include: SCA Java Subproject Menu}
{include: Java SCA Menu New}
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{panel:title= How to get involved in development of Java SCA?
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This document is the development guideline for SCA Java project.
* [General Guide|#General Guide]
* [Getting Source code|#Getting Source]
* [Setting up your development environment|#Setup]
* [Building the binary and source distributions|#Distributions]
* [Importing SCA modules into your Development IDE|#IDE]
* [Understanding SCA Code Path|#Code Path]
* [Coding Guidelines|#Coding Guidelines]
* [Testing|#Testing]
* [Maven Build Structure|#Maven Build Structure]
* [Reporting Issues and Providing patches|#Providing patches]
* *Development Hints*
** [Generating Eclipse WTP Web Projects for Webapp samples|#Webapp in Eclipse]
** [Generating Dependencies for Ant in Samples|#Ant]
* [How to do a release of Tuscany? |#Release Checklist]
* [Logging, Tracing, and Timing in
Tuscany|http://cwiki.apache.org/confluence/display/TUSCANY/Logging%2C+Tracing%2C+and+Timing+in+Tuscany]
\\
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h3. {anchor:General Guide} General Guide
Welcome 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.
* Java SCA sub-project aims to provide enterprise-grade service infrastructure
based on SCA.
* Tuscany SCA is not just a reference implementation. We encourage innovation
based on the tenets of SCA. A lot of work we do provides feedback to the
specifications.
* The Java SCA infrastructure should provide flexibility and choice. It should
not dictate programming models but support many.
* The Java SCA infrastructure is very modularized and is designed to be highly
extensible so users can customize it to fit their needs.
h3. {anchor:Prerequisites} Prerequisites
Java SCA requires the following:
* [JDK 5.0\+ (J2SE 1.5.0+)|http://java.sun.com/j2se/1.5.0]
* [Apache Maven (2.0.7+)|http://maven.apache.org/]
* [Subversion (1.2+)|http://subversion.tigris.org/] or [TortoiseSVN
(1.4.x+)|http://tortoisesvn.tigris.org/]
h3. {anchor:Getting Source} Getting Source code
The Java SCA project Subversion repository is located at
[https://svn.apache.org/repos/asf/tuscany/sca-java-1.x/trunk/].
The repository can also be viewed online at
[http://svn.apache.org/viewvc/tuscany/sca-java-1.x/trunk/]
Anyone can check code out of Subversion. You only need to specify a username
and password in order to update the Subversion repository, and only Tuscany
committers have the permissions to do so.
h4. Checking out code from Subversion
Use the command as follows (note that it uses http scheme so if you're a
committer change it to https):
{code}
svn checkout http://svn.apache.org/repos/asf/tuscany/sca-java-1.x/trunk/
sca-java-1.x
{code}
h4. Committing Changes to Subversion
Any Tuscany committer should have a shell account on svn.apache.org. Before you
can commit, you'll need to set a Subversion password for yourself. To do that,
log in to svn.apache.org and run the command svnpasswd.
Tuscany committers should configure these properties in the svn per-user
config. On Unix-like systems, this area appears as a directory named
.subversion in the user's home directory. On Win32 systems, Subversion creates
a folder named Subversion, typically inside the Application Data area of the
user's profile directory (C:\Documents and Settings\<user name>\Application
Data\Subversion, which, by the way, is usually a hidden directory).
Please make sure the following properties are set in the "config" file:
{code}
[miscellany]
...
enable-auto-props = yes
[auto-props]
### The format of the entries is:
### file-name-pattern = propname[=value][;propname[=value]...]
### The file-name-pattern can contain wildcards (such as '*' and
### '?'). All entries which match will be applied to the file.
### Note that auto-props functionality must be enabled, which
### is typically done by setting the 'enable-auto-props' option.
*.c = svn:eol-style=native
*.cpp = svn:eol-style=native
*.h = svn:eol-style=native
*.dsp = svn:eol-style=CRLF
*.dsw = svn:eol-style=CRLF
*.sh = svn:eol-style=native;svn:executable
*.txt = svn:eol-style=native
*.png = svn:mime-type=image/png
*.jpg = svn:mime-type=image/jpeg
Makefile = svn:eol-style=native
*.java = svn:eol-style=native;svn:keywords=Rev Date
*.xml = svn:eol-style=native;svn:keywords=Rev Date
*.xsd = svn:eol-style=native;svn:keywords=Rev Date
*.html = svn:eol-style=native;svn:keywords=Rev Date
*.properties = svn:eol-style=native;svn:keywords=Rev Date
*.jelly = svn:eol-style=native;svn:keywords=Rev Date
*.ipr = svn:eol-style=native
*.iml = svn:eol-style=native
{code}
Once your password is set, you can use a command like this to commit:
{code}
svn commit
{code}
If Subversion can't figure out your username, you can tell it explicitly:
{code}
svn --username <name> commit
{code}
Subversion will prompt you for a password, and once you've entered it, it will
remember it for you. Note this is the password you configured with svnpasswd
not your shell or other password.
h3. {anchor:Setup} Setting up your Development Environment
h4. Build tree structure
The build tree is designed to facilitate modular development and releases.
Maven modules are grouped by how they are released under an hierarchy. Java SCA
currently have the below module hierarchy :
{noformat}
-java
|-- sca
|-- demos SCA demo applications
|-- distribution SCA distributions
|-- itest SCA Integration Tests
|-- modules SCA Implementation Modules (core, runtimes,
contribution, extensions, etc)
|-- samples SCA Sample Applications
|-- tools SCA Tools (Eclipse plugins, wsdl2java, java2wsdl,
etc)
|-- tutorial SCA Tutorial
{noformat}
The individual modules can be built separately or build with top-down build.
h4. top-down build (recommended approach)
Check out all of the java source code.
{code}
svn checkout http://svn.apache.org/repos/asf/tuscany/sca-java-1.x/trunk/
sca-java-1.x
{code}
Building the SCA source code is simple
{code}
cd sca-java-1.x
mvn
{code}
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.
(on) There can be occasional problems downloading artifacts from remote Maven
repositories so if mvn fails with network related sounding messages sometimes
just trying again can fix the problem.
(on) The trunk code sometimes has SNAPSHOT dependencies which can get out of
date in your local repository so if you see odd build failures try updating the
SNAPSHOT jars with:
{code}
mvn -U
{code}
(on) Once you have done a top-down build, and your local maven repository is
populated, you can start using the maven off line option to speed up the build
process
{code}
mvn -o
{code}
{info}
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
Unix : export MAVEN_OPTS=-Xmx512m
{info}
{info}
The "trunk" is always in very active development, and sometimes you might
experience issues trying to build some modules, in that case you can tell maven
to continue building other modules
{code}
mvn -fae clean install
{code}
or either skip all unit tests
{code}
mvn -fae -Dmaven.test.skip=true clean install
{code}
or run tests, but do not stop building if one of the tests fails
{code}
mvn -fn clean install
{code}
{info}
h4. {anchor:Distributions} Building the binary and source distributions
The binary and source distribution release artifacts are created by running
maven in the distribution folder, for example:
{code}
cd sca-java-1.x/distribution
mvn clean install -o
{code}
The distribution artifacts can then be found in the folder named "target"
within the distribution folder.
h3. {anchor:IDE}Importing SCA modules into your Development IDE
h4. Using Eclipse
If 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 :
{code}
mvn -Declipse.workspace=[path-to-eclipse-workspace] eclipse:add-maven-repo
{code}
In order to generate the necessary project files to import the SCA modules to
Eclipse, you can use the maven eclipse plugin
{code}
cd sca-java-1.x
mvn -Peclipse eclipse:eclipse
{code}
Now, launch your Eclipse IDE, select File->Import->Existing projects into
Workplace, and then select the base SCA directory (e.g java/sca) and then press
Finish, this should import all SCA modules into your Eclipse Workspace.
There are some Tuscany Eclipse code templates available:
[Eclipse Style Formatter |
https://svn.apache.org/repos/asf/tuscany/java/etc/tuscany-eclipse-codestyle.xml
]
[Eclipse Templates |
https://svn.apache.org/repos/asf/tuscany/java/etc/tuscany-eclipse-codetemplates.xml
]
h3. {anchor:Code Path} Understanding SCA code path
Here is a walk through of [key methods/functions|SCA Java Get Started with
Coding] which help you get started with SCA Java development.
h3. {anchor:Coding Guidelines} Coding Guidelines
There are a few simple guidelines when developing for JAVA SCA:
* The basic coding style used is the described at [Sun Java coding
standards|http://java.sun.com/docs/codeconv/] but the main thing is to be
consistent with the existing code you're updating, so for example, if you're
updating a method that uses the braces on the same line style don't add code
with the hanging braces style.
* Always include the Apache License Headers on all files (both source code
files and resource files such as xml documents)
* Include a descriptive log message for checkins, for example "fixed such and
such problem".
Some other useful suggestions:
{panel:title=Clean Code|borderStyle=solid}
- use correct visibility, private, default, public, avoid protected
- make methods static if not using object state
- make sure javadoc is in sync or remove that javadoc
- no javadoc on overridden methods
- test cases in same package to avoid having to over-open access to methods
- don't create artificial dependencies by using constants from another module
- don't extend/implement a 'constant' interface
- avoid creating another private layer over a public interface/spi
- remove old code, don't leave it commented out, very confusing
- use functional programming names for functions that convert an object
- add javadoc to private methods
- review class javadoc and make sure it's accurate
- inline methods used only once, or make them clean static functions
- put utility methods in a Util class with package visibility
- use static imports
- use scoped variables
- no stars in OSGi exports
- correct use of generics, see the effective Java book
{panel}
{panel:title=Unit/Integration Tests|borderStyle=solid}
- put comments in test cases
- review test cases and make sure they're included in the build
- use junit 4 only, check correct use of @BeforeClass or @Before
- use static imports for assert statements
{panel}
{panel:title=Formatting|borderStyle=solid}
- use Tuscany eclipse code style/formatter
- no tabs
- no excessive line wrapping
{panel}
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/]
h4. Naming conventions to increase consistency
*Folder Names:* Please use all lowercases and dashes in folder names (like in
the jar names)
- Maven artifact id = tuscany-<folder name>
*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.\*
h3. {anchor:Testing} Testing
Tuscany 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.
{code}
/**
* Description of your test case and necessary details you find necessary
*/
public class YourTestCase extends TestCase {
private SCADomain domain;
private YourService service;
@Override
protected void setUp() throws Exception {
domain = SCADomain.newInstance("YourTest.composite");
service = domain.getService(YourService.class, "serviceName");
}
@Override
protected void tearDown() throws Exception {
domain.close();
}
...
}
{code}
(on) Note that we use surefire maven plugin to run the unit and integration
tests, and in most cases, they are configured to match a \**/*TestCase.java
file name pattern. Because of this, if your test case has a different file name
pattern, you might execute it from your IDE of choice, but the maven build
won't execute the test.
h3. {anchor:Maven Build Structure} Maven Build Structure
_We use the term Module to refer to the leaf of maven tree._
* sca/pom.xml's parent will be pom/parent/pom.xml
* Other poms will use the pom from the parent folder as parent pom
* Group id: org.apache.tuscany.sca
* Version of our modules will be specified once in java/sca/pom.xml, child poms
don't need specify a version as they get it from their parent
* pom names begin Apache Tuscany SCA
* Eclipse projects are generated for all built modules using mvn \-Peclipse
eclipse:eclipse
h4. 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.
h3. {anchor:Providing patches} Reporting issues and providing patches
{include: Found a Bug Section}
{HTMLcomment:hidden}{children:sort=creation}{HTMLcomment}
h2. Development Hints
h3. {anchor:Webapp in Eclipse} Generating Eclipse WTP Web Projects for Webapp
samples
If you're using Eclipse WTP and want to get WTP Web Projects generated
for our Webapp samples you can simply pass a \-Dwtpversion=1.5 option to
the usual mvn eclipse:eclipse command, like this:
mvn \-Dwtpversion=1.5 \-Peclipse eclipse:eclipse
The magic \-Dwtpversion=1.5 option will add the WTP Web project nature to
all the Eclipse projects with <packaging>war</packaging> in their Maven
pom.xml. You'll then be able to add these projects to a WTP Tomcat or
Geronimo Server configuration, to publish and run them straight from
your Eclipse workspace.
h3:{anchor:Ant} 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
script which works in Linux environment for war files.
{code}
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
{code}
h2. {anchor:ReleaseChecklist} How to do a release of Tuscany?
Here is the [Checklist for doing a Tuscany SCA Java release |
http://cwiki.apache.org/confluence/display/TUSCANY/Making+releases].
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