Java Open Source Training

Java Open Source Development
Intertech
March, 2006

Open Source (& Java Open Source) is Big
There are over 110,000 open source projects today!
There are about 20,000 Java open source projects!
Nov 2004 report suggests 67% of all companies use open source products.
With an 16% additional expected to join in 2005.1
Sept 2003 reports suggests 41% of application development tools are open source.2
It's Big
1 - http://www.informationweek.com/story/showArticle.jhtml?articleID=51201599&tid=5979
2 - http://www.dwheeler.com/oss_fs_why.html

Our Objectives
This dialogue is an exploration of some of the more popular Java open source products/tools.
With some 20K projects to choose from, we can’t look at them all.
Give you a broad picture of Java open source landscape.
Give you some options to explore for your own projects.
Give you resources for more information/exploration.

This is an Exchange – not a Lecture
Did we mention this was a dialogue?
We welcome and encourage audience participation.
What open source products/tools have you encountered?
What worked well for you?
What blew chunks?
What else would you include in our survey?
Impromptu show-of-hands surveys should also help give you and idea of popular products in this area.

Open Source Categorization
To assist in our examination, we break Java open source projects up into several categories.
User interface/Web frameworks
Middleware and integration products
Persistence frameworks
Design and development tools
Testing tools and frameworks
Support/Maintenance tools
Miscellaneous products
Some products/tools cut across several categories.

Product/Tool Examination
What is the product/tool’s purpose?
How long has it been in existence?
Benefits/Issues
Commercial counterparts/competitors
If they exist
Where “popular” competing projects exist
Compare and contrast
Project’s future
We have left off Sun’s reference implementations.
We assume everyone knows how to examine/get these.
In many cases, these maybe your best option.

An Open Source Drive-By Tour
With the time we have, we only have time to mention products.
Explore their general use/purpose.
This is not a detail dive into the products.
Unfortunately work left for you.

Defining “Popular”
We couldn’t possibly hit all the projects.
We focus on popular tools/products
Popular = widely used and active
We also measure “popular” by:
Ownership – who is in charge of the project now.
Current Web site – and its last update.
Documentation – quantity and quality.
Setup/download – ease of getting/setting up the product/tool
Forum/blog/news groups – what others are saying and how often (especially for support)

User Interface & Web Frameworks
MyFaces (JSF)
Struts
Tiles
WebWork
Cocoon
Spring
Tapestry
jCharts
jFreeChart
JasperReports
jFreeReports
TagLibs (JSTL)
Lucene
Xalan

MVC Frameworks
Purpose of Struts and JSF: application frameworks for building Web applications
Struts – the old stand-by
struts.apache.org
Launched in 2000
Creator same as JSF (Craig McClanahan – now with Sun)
JSF – the new stand-by
MyFaces – Apache implementation of JSF
myfaces.apache.org
Launched 2005 (JSF launched in 2004)
Many of the frameworks can be weaved together.

Struts
Field validation
Locale/internationalization support
Plenty of extensions.
Tiles framework for sophisticated layout management
WebWork now folded into Struts Action Framework

MyFaces (JSF)
Implementation of Sun standard
JEE 5.0 containers must provide an implementation of JSF
First free implementation of JSF
Focus on View of MVC (more “fat client” like).
JSF  Struts + Swing
Rich component model with event handling and component rendering
JSF components handle the purely visually-oriented HTTP requests (example – clicking on a tree control).
Business events go through the standard Struts-request-processing lifecycle (example – add this to my cart).

Struts vs. JSF
McClanahan's Weblog
blogs.sun.com/roller/page/craigmcc/20040927#struts_or_jsf_struts_and
Bottom-line
Struts users - think about migrating slowly to JSF
New projects – think JSF
The two can co-exist
Unless unusual needs exist

Cocoon
An XML publishing framework.
Based on Servlets.
Manipulate the presentation layer using XSLT
Includes a technology called "XSP" for Extensible Server Pages.
Focus on separation of concerns
Uses concept of component “pipelines” to process requests
cocoon.apache.org
Around since 1999
Version 2.0 recently released

Cocoon Pipelines

Tapestry
Also a Java MVC Web application framework.
Builds on the standard Java Servlet API
Its ability to blend into a standard HTML markup is its distinguishing and most valuable feature
Doesn’t use JSPs
Tapestry “templates” are regular HTML, decorated with Tapestry attributes
Inspired JSF Facelets
jakarta.apache.org/tapestry
Started in 2000
Just release version 4
Good comparison of JSF to Tapestry at:
www.theserverside.com/articles/article.tss?l=JSFTapestry

Spring Application Framework
A comprehensive, layered Java/J2EE application framework
www.springframework.org
Started 2003
Version 2 soon to be released
Features
A complete lightweight container
Aspect oriented framework
Assembly of loosely-coupled POJOs
A common abstraction layer for transaction management.
A JDBC abstraction layer that can be integrated to/use Toplink, Hibernate, JDO, etc.
Flexible/extensible app framework
SpringMVC  Struts++

Spring Framework

Java Charting tools
Dozens of options
Many open source options at java-source.net/open-source/charting-and-reporting
Commercial competitors include: JClass, EspressChart, ChartFX, and many more…
jFreeChart
www.jfree.org/jfreechart/index.php
First released in 2000
Krysalis jCharts
jcharts.sourceforge.net
First released in 2000

Java Reporting tools
Dozens of options
Many open source options at java-source.net/open-source/charting-and-reporting
Commercial competitors include: Formula One, JReport, and many more…
JasperReports
jasperreports.sourceforge.net
www.jaspersoft.com
“Most popular embeddable open source reporting library”
JFreeReport
sourceforge.net/projects/jfreereport
Introduced in 2002

TagLibs
Is an “open source repository for JSP custom taglibraries and associated projects.”
jakarta.apache.org/taglibs
Includes the reference implementation of the Java Server Pages Standard Tag Library (JSTL)
Includes
JCP Standardized Tag Libraries (JSTL) a collection of tag libraries that cover conditionals, iterators, accessing URL resources, internationalization and text formatting, database access (SQL), and XML processing.
Custom Tag Library Extensions (CTLX) are extensions for popular web publishing tools

Lucene
A high performant, scalable and full-featured text search engine library.
Allowing you to add indexing and searching capabilities to your apps.
lucene.apache.org
Many well known web sites use Lucene (including Wikipedia, FedEx, Eclipse.org, etc.)
Around since ’97/’98
First open source release in 2000
There are competing products
Not all Java
Not as well used.
Also behemoths like Google, Yahoo, etc. in this arena.

Xalan Java (Xalan-J)
An XSLT processor for transforming XML documents into HTML, text, or other XML document types.
Implements XSL Transformations (XSLT) Version 1.0
Implement XML Path Language (XPath) Version 1.0
Implements JAXP 1.3
Builds on SAX 2 and DOM level 3 parsers
Can be used from the command line, in an applet or a servlet, or as a module in other program.
xml.apache.org/xalan-j
Actually two versions of Xalan (Java and C++)
Used to be part of the Apache XML Project
Alternate: Saxon

Middleware & Integration Products
JBoss
JOnAS
Enhydra
Tomcat
Jetty
Resin
James
Axis
Xerces
OpenJMS
MantaRay
ActiveMQ
JORAM

Application Servers
Full J2EE Stack containers
Supporting servlets, EJBs, JMS, JCA, etc.
JBoss (jboss.org – claims to be the #1 Java app server on the market)
JOnAS (jonas.objectweb.org)
Enhydra Enterprise (www.enhydra.org)
Apache Geronimo (geronimo.apache.org - just released version 1.0)
GlassFish – Sun’s open source EE app server (https://glassfish.dev.java.net/)
WebSphere and WebLogic are biggest commercial competition
Oracle a somewhat distant third.
“During the next two years, open source application servers will gain share in the J2EE market, forcing further vendor consolidation“ – says the Meta Group1
1 http://www.theserverside.com/news/thread.tss?thread_id=24501

App Server (cont.)
Servlet/JSP/Web containers
Tomcat (tomcat.apache.org)
Jetty (jetty.mortbay.org/jetty)
Resin (www.caucho.com - has some EJB functionality)
See Server Side’s App Server Matrix
www.theserverside.com/articles/article.tss?l=ServerMatrix

James
James is a SMTP and POP3 Mail server and NNTP News server.
Also provides a Java mail API for use in applications
Lets you write Java code email processor – called mailets.
Mailets can generate an automatic reply, update a database, prevent spam, build a message archive, etc.
Rumor has it future releases may support instant messaging.
james.apache.org
James is based upon the Apache Avalon application framework.

Axis - SOAP Toolkit
Axis is a tool kit for working with SOAP and WSDL
SOAP and WSDL are the backbone XML documents in Web services.
Axis shields developers from the details of dealing with SOAP and WSDL
Axis is the most popular implementation of JAX-RPC.
ws.apache.org/axis
Few real alternatives, but are some add-ons
See java-source.net/open-source/web-services-tools

Xerces Java (Xerces-J)
An XML parser.
Fully conforming XML Schema processor
Supports SAX 2
Supports DOM level 3 and 2
xerces.apache.org
Actually two versions of Xerces (Java and C++ - also have a Perl wrapper version)
Used to be part of the Apache XML Project
Alternate: many
See java-source.net/open-source/xml-parsers

JMS Implementations
There are several open source Java Message Service API implementations.
OpenJMS
ActiveMQ
JORAM
Mantray
See java-source.net/open-source/jms
Full J2EE servers also support JMS.
Open source ESBs – still emerging
ServiceMix (ActiveMQ producer)
OpenESB (open-esb.dev.java.net)
Celtix (celtix.objectweb.org – Iona and ObjectWeb)

Persistence & Persistence Frameworks
Hibernate
Castor
ObjectRelationalBridge(JDO)
DBCP
HypersonicSQL
MySQL

Hibernate
Attempts to be “non-intrusive” persistence solution.
A lightweight object/relational mapping service.
Using POJO’s and Java reflection
Isolating mapping and SQL in XML configuration files
Provides several means to access data including Hibernate’s own HQL
www.hibernate.org
Hibernate 3 now available
The foundation of entity beans (EJB) in EJB 3.0
Started in 2001
Winner of Software Development Jolt award

Castor
Provides Java-to-XML binding and Java-to-SQL persistence.
Two products: Castor XML and Castor JDO
JDO similarities but not compliant with Sun’s JDO spec.
SQL statements are automatically generated for loading, updating, creating and deleting.
Uses subset of ODMG's query language
www.castor.org

ObJectRelationalBridge - OJB (JDO)
JDO (Java Data Objects) is a Java specification
java.sun.com/products/jdo
Finalized in 2002
Transparent persistence framework accomplished through byte code enhancement (which some don’t like).
Spec does not dictate the type of data store (relational or object-oriented databases).
Spec does not address object to relational mapping (mapping files will not be portable)
OJB is an open source JDO implementation
db.apache.org/ojb
Many open source and commercial implementations of JDO
KodoJDO is leading commercial implementation.
See www.jdocentral.com.

Comparing Persistent Frameworks
Options
Roll-your-own with JDBC/POJOs
OR mappers á la TopLink, CocoBase
Hibernate
JDO implementations
EJBs
Other open source options (Castor, iBATIS)
Bruce Tate and others have given several talks
dev2dev.bea.com/pub/a/2003/07/Java_Persistence.html (although some comments are outdated)
Outlining pros/cons of each

DBCP
Part of the Apache commons project (more in a bit)
Provides database connection pooling services
Tomcat and James use DBCP
jakarta.apache.org/commons/dbcp/
There are several connection pool utilities.
Most servers have them built in.

Hypersonic SQL (HSQLDB)
Hypersonic SQL is full relational database engine.
Written in Java
Provides a JDBC driver
Supports a large subset of ANSI-92 SQL
PolePosition is a benchmark test suite to compare database engines and object-relational mapping technology.
Found HSQLDB/JDBC to be one of the more performant open source DBs (www.polepos.org)
Offered as optional/free database server for many commercial products
Example: Systinet Registry
hsqldb.org
There are a number of Java open source RDBMS.
Of course, MySQL, though not Java, is the world's most popular open source database

Design and Development Tools
Eclipse
NetBeans
jEdit
Java CVS Client
SQuirreL
ArgoUML
JLint
Velocity
Jalopy
ProGuard
Ant
AntHill
Commons
XDoclet
Maven we save for later.

IDEs and Editors
IDEs – many to choose from; few widely used
Eclipse (Eclipse.org)
NetBeans (NetBeans.org)
Significant commercial competitors (WSAD, IntelliJ, JBuilder,..)
Java Editors – many to choose from
jEdit – (www.jedit.org)
TextPad (textpad.com - not Java) – also provides Java edit, compile, execution
JBuilder is not being open-sourced despite reports on Registry.com

Eclipse vs. NetBeans
Eclipse
Based on IBM/OTI’s work which started in ’98
Released to open source in 2001
Built on premise of plug-ins on top of base platform
Dozens of plug-ins and projects
Allows for non-Java development
Most popular IDE
Requires assembly of many plug-ins based on needs
NetBeans
Made open source by Sun in 2000
Heavily influenced by Sun
Governed by community and 1/3 by Sun
More all-encompassing/inclusive (no plugins required) Java develop platform

Additional Development Tools
jCVS – a Java CVS Client (www.jcvs.org)
SQuirreL – a Java SQL client application (squirrel-sql.sourceforge.net)
ArgoUML – UML 1.4 design tool (argouml.tigris.org)
JLint – Java code checker looking for bugs, inconsistencies and synchronization problems (artho.com/jlint)
Velocity – a template engine (jakarta.apache.org/velocity)
Used in several Apache projects
Jalopy – code formatter (jalopy.sourceforge.net)

Additional Development Tools (cont)
ProGuard – code obfuscator (proguard.sourceforge.net)
Many IDEs, like NetBeans, uses ProGuard
Ant – build tool (ant.apache.org)
Antelope - A GUI for running Ant and editing build files (antelope.tigris.org)
AntHill – controller for the build process (www.urbancode.com/projects/anthill)
XDoclet – A source code or other document generation engine (xdoclet.sourceforge.net/xdoclet)
XDoclet is an extension to the Javadoc Doclet engine
Commons – a library of all sorts of reusable Java components (jakarta.apache.org/commons)
There are often many competitors – these tend to get most of the attention in their perspective area.

Testing Tools & Frameworks
JUnit
HttpUnit
HtmlUnit
JUnitPerf
Cactus
Jameleon
JMeter
Abbot

Unit Testing
JUnit is the original unit regression testing framework
www.junit.org
Has many extensions and IDE adapters
HttpUnit is a unit testing framework for testing web based applications
www.httpunit.org
HttpUnit models the HTTP protocol – testers deal with request and response objects.
HtmlUnit is also a unit testing framework for testing web based applications
htmlunit.sourceforge.net
HtmlUnit models the returned document – testers deal with pages and forms and tables.
JUnitPerf is a collection of JUnit test decorators used to measure the performance and scalability within existing JUnit tests.
www.clarkware.com/software/JUnitPerf.html
Cactus is a framework for unit testing server-side java code (Servlets, EJBs, tags, Filters, ...).
jakarta.apache.org/cactus
Extends JUnit

Beyond Unit Testing
Jameleon is an integration and acceptance-level testing tool.
jameleon.sourceforge.net
JMeter is a tool to load test and measure (performance) functional behavior
jakarta.apache.org/jmeter
Abbot is a tool for unit and functionally testing Java GUI (Swing/AWT)
abbot.sourceforge.net
A lot of commercial competition in testing market
Mercury, CompuWare, Quest (JProbe) and others
See opensourcetesting.org for other open source alternatives

Support & Maintenance Tools
Log4J
Quartz
Scarab
Maven
Bugzilla

Log4J
Ubiquitous framework for logging application debugging messages.
JDK logging offer similar functionality today.
Apache Commons provides a bridge to either logging utility
Sometimes Log4J will conflict with other logging packages in environment/server
logging.apache.org/log4j
Around since 1998
Version 1.3 expected this year (2006)

Quartz
Quartz is a job scheduling system
Jobs run on any number of triggers.
Quartz can run stand-alone or in a cluster
It can run embedded within another application
It can be instantiated within an application server or servlet container)
It can participate in XA transactions
www.opensymphony.com/quartz
Flux is a commercial competitor

Project Management
Maven
A “software project management and comprehension” tool.
Initially started as a means to simplify the build processes in the Jakarta Turbine project.
Uses concept of project object model.
It is a site and documentation tool
It extends Ant
maven.apache.org
Scarab
Scarab is an issue and artifact tracking tool.
scarab.tigris.org
Bugzilla is leading open source bug tracking tool.
Not Java!
Plenty of commercial competition on management tool side.

Java JVM
Miscellaneous
Jikes – IBM open source JVM
Developed in 1997 by IBM alphaWorks
Typically faster than Sun’s JVM implementation
Usually comes with Linux distributions
jikes.sourceforge.net
AspectJ
Aspect-oriented extension to Java
www.eclipse.org/aspectj
Java and other language mixes
Groovy – Java-like scripting language on JVM (groovy.codehaus.org)
JRuby – Ruby interpreter in Java
(jruby.sourceforge.net)
Jython – Python interpreter in Java
(www.jython.org)

Wrap Up
Raise the open source awareness level!
There is probably an open source tool for almost every part of your application’s lifecycle.
In most cases there is more than one option.
Even if you have the funding for commercial products
Explore open source alternatives – may be just as good or better
Explore the features, benefits, issues so you know what you want in a commercial alternative

Recourses
For more information, check out these references:
java-source.net
jakarta.apache.org
TheOpenSourcery.com
SourceForge.net
OSDir.com (O’Reilly’s open source page)
FSF.org (Free Software Foundation)
Gnu.org
Richard Monson-Haefel on “Rebel Frameworks”
http://www.burtongroup.com/research_consulting/doc.aspx?cid=650