Creating Multiple Java Class Libraries and Test Suites
from a Single Source
DEMO
Ken Walker, J9 JCL Manager
ken_walker@ca.ibm.com
Gabriel Castro, J9 JCL Developer and J9 VM Tooling Lead
Gabriel_Castro@ca.ibm.com
J9 Embedded Java Class Library Team
IBM Ottawa Lab
© 2007 by Ken Walker, Gabriel Castro – IBM Canada; made available under the EPL v1.0 | March 7th, 2007

J9 VM and JCL History
 IBM (ex OTI) VM Team
 Current offerings based on the J9 Virtual Machine
 3rd generation Java VM from IBM
 VisualAge Smalltalk
 VisualAge for Java (Smalltalk and Java bytecodes)
 J9 Java Virtual Machine (August 1998)
 Designed from the ground up to be a scalable solution
for embedded, desktop, and server class hardware
 Common code base for all Java ME and Java SE products
 Highly configurable—pluggable interfaces with different implementations
depending on the target market
 Class library independence
 Class Libraries can change at runtime
2 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

J9 VM and JCL History continued…
 Predated Java 2 Micro Edition
 Created 3 Custom Class Libraries
 Strict Subsets of J2SE 1.1.8
 JCL Xtreme (~100K)
 JCL Core (~300K)
 JCL Max (~2 Mb)
 Implemented in a “Cleanroom” fashion
 From specification only
 Limited access to network and zero access to source
 J2ME Introduced JavaOne 1999
 With our preprocessing infrastructure it was easy to migrate to
support both “Custom” and “Compliant” Libraries
3 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

J9 JCL Single Sourced
 We do not have separate projects for each target JCL configuration
 Preprocessed into correct library subsets of the Master Source
 This is done via automated builds and via an Eclipse Plugin for local
development
J9 JCL Master Source
Preprocess -CLDC Preprocess -MIDP Preprocess -Foundation
J9c.exe J9c.exe J9c.exe
CLDC Source MIDP Source Foundation Source
Zip compiled Zip compiled Zip compiled
Source of CLDC Source of MIDP Source of Foundation
To classes.zip To classes.zip To classes.zip
4 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

Demo
Eclipse Tooling for JCL Libraries Java
5 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

J9 JCL Unit Tests
CLDC classes.zip
 JCL JUnit tests are also single sourced
 Master contains all test cases
 Testcase generator selects test based J9 JCL Automated Test Source
on target runtime library API
J9 Test Case Generator
Produces SRC directory
Ready for Preprocessing
Preprocess –CLDC
The preprocessed SRC Directory
J9c.exe the post processed
JUnit Test Suite Source
Zip compiled source
Into TestsCLDC.zip
Run tests against j9.exe –jcl:cldc
6 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

J9 JCL Unit Tests…
 Several extensions to JUnit framework
 Supports CLDC 1.0 testing
 Support exclude lists
 Excludes by platform and testname
 some platforms are just too fussy
 Tests themselves can have preprocessor directives
 Both Bootclasspath and classpath tests
 On to the demo….
7 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

J9 JCL Tooling Summary
 Allows the team to single source many varied class libraries
 Multi-Stream development would not have been sane
 UI Teams also use the tooling for AWT and MIDP LCDUI Development
 When a bug is reported
 Master source is fixed
 Testcase is created matching bug report
 Both released back to source control
 Distributed builds take over
 Create all known class library configurations
 Create all test suites
 All test suites are executed on varied platforms
 TCKs are executed on Compliant Configurations (CLDC, MIDP, etc.)
 Build results are posted to the web
 Distributed builds happen many times per day or can be individually
kicked off by developers on a private build
8 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada

Questions?
 Email us: ken_walker@ca.ibm.com ,
gabriel_castro@ca.ibm.com
 Come find us and chat about the technology
9 IBM J9 Class Library Development Demo | © 2007 by Ken Walker, Gabriel Castro – IBM Canada