Ekkehard Gentz, Independent Software Architect
HowTo Build an OSGI EJB3 Server
OSGI Experts Day 2009-05-24
1
 (c) 2009 ekkehard gentz, eclipse public license EPL

Who am I
 ekke
 Ekkehard Gentz, Rosenheim
 Freelancer, Software Architect, ERP Consultant
 Business Developer (ERP Solutions)
 Assembler, Cobol, Pascal,4GL, Java
 Domains: Apple Dealer, Paper Manufacturer, Waste &
Recycling, ...
3

Why this session
 So many articles and guidelines about OSGI:
 how to do it the right way
 Is this reality for OSGI Enterprise Apps ?
you have to...
 ... live with existing code
 ... use 3rd party bundles
 ... integrate different OSGI products, frameworks etc
4

Business Project Overview
 Project built from scratch
 Business Processes and Rules change 'daily'
 Short time-frame
 Small Project Ressources
 Possible to make it run ?
6

7

Business Project Requirements
 Easy to use for business users
 Server 24*7 online
 Rich Clients with great UI comfort
 Processes and Rules change heavy and often
 Has to run on different OS (XP, Vista, OSX)
8

Project Decisions
 Frameworks
 Tools
 Technology
9

Design and Modeling Tools
 UML (MagicDraw)
 MD DSL Customization Engine
 MD Customized Domain-Specific Editors
 MD Reader available
 Eclipse - Integration
 Why not EMF - only ?
 Combine UML and EMF
 oAW as Generatorframework
10

Eclipse RCP (SWT) as Rich Client
 Eclipse RCP Platform
 plus Riena UI
 Ridgets
 Markers
 Validators
 plus Riena Navigation
 plus redView dynamic Views for Business Apps
 CDO distributed view models
11

OSGI (Equinox) as Server
 OSGI
 modular, dynamic updates
 flexible server architecture
 Why Equinox as OSGI Framework ?
 its Eclipse ;-)
 Riena uses Buddy Policy
 so I‘m bound to Equinox
12

Services and Persistence: EJB3, JPA
 Easybeans choosen
 pure OSGI bundle implementation
 vs WSAD, Glassfish or other OSGI-based JEE Server:
 integrate Easybeans into your OSGI Enterprise app
 all is under your control, no deploy to Appserver
 Hibernate as JPA provider
 my knowledge of Hibernate
 already bundled with EasyBeans OSGI
13

Drools Business Rules and Process Flow
 First decision: jBPM + Drools
 jBPM as BusinessProcess Engine
 Drools as Rules Engine + Decision Nodes in jBPM
 Drools 5 supports both:
 Business Process Flow
 Business Rules
14

RDBMS: IBM DB2 Express
 Relational data and xml data can be mixed
 low costs for small companies
 scales well if company grows
 I know it
15

BIRT as Reporting Engine
 Perfect Integration into Eclipse world
 Reports direct from DB2 RDBMS
 Reports directly using Hibernate Pojos
16

Why OSGI and EJB3
 EJB3 Standard
 Out of the box directly from EJB3 Container
 services
 persistence
 transactions
 OSGI goes Enterprise
 Easybeans OSGI JPA Container
17

Why not CDO to persist Business Models
 Pros:
 all stored in EMF Models, EMF Databinding
 no lazy exceptions from hibernate at client side
 scales very well, persistence (Teneo, Hibernate)
 Cons:
 model evolution not supported, no data-migration
 no reporting tools like BIRT to use CDO repositories
 future: could be an alternate way
18

OSGI Server
 Bundles
 entity
 ejb, interfaces
 enumerations
 Fragments
 icons, fonts, OS-dependent-styles
 Logging Utils, Logging Configuration
19

OSGI Server (Bundles)
 Bundles
@Local,
Business - Interface Bundles
 entity
@Remote
@Stateless,
EJB Bundles
 ejb
@Stateful
@EJB
implements
implements
 interfaces
@Stateless
@PersistenceContext
injects
uses @Entity,
 enumerations @Embeddable
uses
PersistenceContext Bundles
Entity Bundles
Enum
Enumeration Bundles
20

Entity Bundles
 Bundles
@Entity,
 unlimited @Embeddable
 per Subapplication
 per Subdomain Entity Bundles
 Productfamilies
 Tip:
 used at Client and Server
 Server-only Dependencies should be optional
21

Enumeration Bundles
 Bundles
 per Subapplication
Enum
 per Subdomain Enumeration Bundles
 per Customer / Product
 Why separate Bundles ?
 Enumeration Literals different per Customers
 Easy to change / enhance
 Also used by Business Processes, Rules
22

PersistenceContext Bundles
@Stateless
 Bundles @PersistenceContext
 Stateless Beans
 implements BusinessInterfaces PersistenceContext Bundles
 contains PersistenceContext (EntityManager)
 only used at Server
 Tip:
 JIRA EZB-294 all EJB‘s of PersistenceContext = 1 Bundle
 All @Entity and @Embeddable must be listed inside
persistence.xml because of a Bug
23

Persistence MyBean.java (in a PersistenceContext Bundle)
Context
Configuration
META-INF/persistence.xml
Datei
config/easybeans.xml
Datei
24

EJB Bundles
@Stateless,
 Bundles EJB Bundles @Stateful
@EJB
 Stateless or Stateful
 only used at Server
 can inject other EJB‘s from PersistenceContext Bundles
 Productfamilies
 Tip:
 @EJB(mappedName) BusinessInterface
 JIRA EZB-322 can‘t found Interfaces from other Bundles
25

Business Interface Bundles
 Bundles @Local,
Business - Interface Bundles
@Remote
 Local or Remote
 unlimited Bundles
 structured per Subdomain, Product, ...
 used on Client and Server
26

OSGI Server (Fragments)
 Fragments
 Icons
 Fonttemplates
 OS-dependent-styles
 Logging - Utilities
27

MDSD
 openArchitectureWare (oAW)
 perfect integrated into eclipse
 working with UML and EMF models side-by-side
 generating:
 Entity, EJB, Business Interfaces
 BusinessProcess /-rules Integration
 EMF View models from Entity
 configuration files and more
29

oAW
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Eclipse Workspaces and Installations
 Overview
 Different Eclipse Installations for different Roles
 Architect and Modeler
 Client-Server-Platform Developer
 UI Designer (Development)
 UI Design and Prototyping (Business User)
32

Eclipse Workspaces and Installations
Eclipse Installations Eclipse Workspaces
java
entity
Eclipse Modeling my oAW ejb
Cartridges services
processes
Modeling
EMF
UML2
openArchitectureWare uses
- XPand
- XTend
- Workflow
abc
Project foo
Workflows sample
generates
Project code
Project \"foo\"
Eclipse Runtime
Runtime
Target Platform
entity
ejb - beans
Equinox
ejb - api
Project
RCP
services
Bundles
Riena
processes
EasyBeans
rules
ui
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34

Problems to solve
 Integrate 3rd Party
 Bundle Start Order
 Services, ServiceTracker or DS ?
 Logging Frameworks and OSGI
 Dependency Cycles
 Classloader used by 3rdParty
 How to configure Target Platform
 Problems solved using oAW
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36

HowTo integrate 3rdParty Bundles (1)
 Are they all brave OSGI citizens ?
 1 jar == 1 bundle
 import package instead of required bundles ?
 always Versioning Bundles and Dependencies ?
37

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HowTo integrate 3rdParty Bundles (2)
 Are there any Monsters ?
 look inside EasyBeans core bundle
 Are there dependency - cycles ?
 SLF4J + Logback, Easybeans
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42

Bundle Start Order (1)
 Goal: Try to avoid Start-Levels needed
 but 3rdParty:
 Agents like EasyBeans Agent
 Logging first if using Log Bridges from OSGI
 start first to avoid black holes
43

Bundle Start Order (2)
 To make a System run:
 try using Start-Levels
 then Iterations:
 Add OSGI Services
 Add ServiceTracker to start Bundles
 Add DeclarativeServices to reduce ServiceTracker Complexity
44

Bundle Start
Order (3)
45

Bundle Start
Order (3)
ns
io
at
er
it
ly
ar
e
45

Bundle Start Order (4)
 ServerAgent
 tracks Services from EasyBeans using a
ServiceTracker
 registers @Remote Interfaces for Riena
 registers a Service if all is done
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Bundle Start Order (4)
ns
io
at
er
it
ly
ar
e
 ServerAgent
 tracks Services from EasyBeans using a
ServiceTracker
 registers @Remote Interfaces for Riena
 registers a Service if all is done
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Bundle Start Order (5)
 MyServer
 waits for the ServerAgent - Service
 registers a Service if all is ready
 registers this also as RienaRemote Service
 now the Clients know that the Domain Server runs
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Bundle Start Order (5)
ns
io
at
er
it
rly
ea
 MyServer
 waits for the ServerAgent - Service
 registers a Service if all is ready
 registers this also as RienaRemote Service
 now the Clients know that the Domain Server runs
47

Bundle Start
Order (6)
 Using Declarative
Services
 TODO:
 replace
Easybeans Agent
by own
Implementation
using DS
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Bundle Start
Order (6)
 Using Declarative
Services
 TODO:
 replace
Easybeans Agent
by own
Implementation
using DS
48

Services, Services, Services...
 Riena Remote Services
 EasyBeans Services
 ServiceTracker
 Declarative Services (DS)
 ServiceTracker vs DS
49

Riena Remote Services (1)
50

Riena Remote Services (2)
 Publishing Service
51

Riena Remote Services (3)
 Injecting Service
 the Riena Way (fluent interfaces)
 I prefer DeclarativeServices
52

EasyBeans Services (1)
 EasyBeans registers Services for each Business
Interface (@Local, @Remote)
 thanks to the EZB Team:
 changed to ManagedServices, so Properties can easy
used
 in Filters of ServiceTrackers
 or DeclarativeServices (DS)
53

EasyBeans Services (2)
 EasyBeans registers:
 ManagedServiceFactory Services for each EasyBeans
components:Transactions, Mail, JDBCPool, JMS, etc
 EZBContainer Services
EJB3Container ready
PersistenceContext: Hibernate Mapping, Binding
 JDBCPoolComponent
 the DataSource is available
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Service Tracker (1)
 start EJB Bundles ? ManagedServiceFactory registered
all EZB
JDBCPool
Components
Component ?
registered ?
Yes
register JNDI for
DataSource
all DataSources
registered ? Yes
Yes
Start EJB Bundles
55

Service Tracker (1)
 start EJB Bundles ? ManagedServiceFactory registered
all EZB
JDBCPool
Components
ns
Component ?
registered ?
io
at
Yes
er
it
register JNDI for
ly
DataSource
ar
e
all DataSources
registered ? Yes
Yes
Start EJB Bundles
55

Service Tracker (2)
 EasyBeans ManagedServiceFactory registered
Components ?
 carol, hsqldb,
all EZB
Components
registered ?
jotm, quartz,
event, jmx,
jdbcpool, joram
 Services named
like
carol-component-factory

56

Service Tracker (2)
 EasyBeans ManagedServiceFactory registered
Components ?
 carol, hsqldb,
all EZB
Components
ns
registered ?
io
jotm, quartz,
at
er
event, jmx,
it
ly
jdbcpool, joram
ar
e
 Services named
like
carol-component-factory

56

Service Tracker (3)
 DataSources ManagedServiceFactory registered
registered ?
 easybeans.xml JDBCPool
Component ?
Yes
register JNDI for
DataSource
all DataSources
registered ?
57

Service Tracker (3)
 DataSources ManagedServiceFactory registered
registered ?
 easybeans.xml JDBCPool
ns
Component ?
io
at
Yes
er
it
register JNDI for
ly
DataSource
ar
e
all DataSources
registered ?
57

Service Tracker (4)
58

Service Tracker (5)
 start EJB Bundles: ManagedServiceFactory registered
 EasyBeans creates all EZB
EJB3-Container JDBCPool
Components
Component ?
registered ?
for each Yes
PersistenceContext register JNDI for
DataSource
Bundle
all DataSources
registered ? Yes
Yes
Start EJB Bundles
59

Service Tracker (5)
 start EJB Bundles: ManagedServiceFactory registered
 EasyBeans creates all EZB
EJB3-Container JDBCPool
Components
ns
Component ?
registered ?
io
for each
at
Yes
er
PersistenceContext it
register JNDI for
ly
DataSource
ar
Bundle
e
all DataSources
registered ? Yes
Yes
Start EJB Bundles
59

Service Tracker (6)
 EasyBeans registers:
ManagedServices
registered by EasyBeans
ManagedService registered
for Business - Interfaces
implemented by
@Stateless or @Statefull Beans
from EJB - Bundles
 ManagedService for
Remote Business
- Interface ?
@Local, @Remote Yes
register as Riena Remote Endpoint
 EZBContainer
EZB Container Service registered
Service for each EZBContainerServices Container for all
EJB Bundles ?
registered by EasyBeans
EJB3-Container
for each EJB - Bundle
Yes
register
RienaEasyBeansServerService
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Service Tracker (7)
 ServiceTracker now tracks ManagedServices
 tests for some Properties from EasyBeans
 registers Services as RienaRemoteService
61

ns
io
at
Service Tracker (7) er
it
ly
ar
e
 ServiceTracker now tracks ManagedServices
 tests for some Properties from EasyBeans
 registers Services as RienaRemoteService
61

Service Tracker (8)
 All logic around EasyBeans EJB3-Container at a
central point
 Sounds good ?
 Difficult to maintain or to test
 What to do ?
62

Declarative Services (1)
 We can describe the same complex logic solved
with ServiceTracker using
 DeclarativeServices (DS)
 let the OSGI Framework do the work
 easy to maintain
 lazy loading of Bundles
 Eclipse 3.4 Ganymede: edit XML files
 Eclipse 3.5 Galileo: PDE Tooling-Support
63

ion
lut
Declarative Services (1) so
al
fin
 We can describe the same complex logic solved
with ServiceTracker using
 DeclarativeServices (DS)
 let the OSGI Framework do the work
 easy to maintain
 lazy loading of Bundles
 Eclipse 3.4 Ganymede: edit XML files
 Eclipse 3.5 Galileo: PDE Tooling-Support
63

Declarative Services (2)
 Example „EasyBeans Components started ?“
64

ion
lut
Declarative Services (2) so
al
fin
 Example „EasyBeans Components started ?“
64

Declarative Services (3)
 Example „EasyBeans Components started ?“
65

ion
lut
Declarative Services (3) so
al
fin
 Example „EasyBeans Components started ?“
65

Declarative Services (3)
 OSGI Runtime with DeclarativeServices
 Wondering why a DS not started ?
 Tip:
 set debug-trace-log vm-parameters:
-Dequinox.ds.debug=true
66

Declarative Services (4)
 Console Output:
67

Declarative Services (5)
 some more Properties:
 equinox.ds.print=true prints tracelogs to console
 equinox.ds.perf=true logs execution times in ms
 equinox.scr.waitTimeOnBlock=10000 how many ms
should DS ait until a service component is ready
68

Service Tracker vs Declarative Services
 Are DS replacement for ServiceTracker (ST) ?
 ST has access to all methods of a Service
 DS only access to properties
 Missing graph visualization for some Dependencies
69

Service Tracker vs Declarative Services
 Over all my recommendation:
 Use Declarative Services where possible
 Equinox DS will do all the difficult work for you
70

Logging with OSGI and 3rdParty
 OSGI Logging
 'classic' Logging
 Compare LoggingFrameworks
 HowTo integrate them all
71

OSGI Logging
 LogService
 Equinox Extended LogService
 graduated soon
72

Classic Logging
 Log4J
 CommonsLogging
 SLF4J
 JDK Logging (java.util)
73

Logging used by ...
 ...Easybeans
 Commons-Logging
 JDK Logging
 Riena
 Extended LogService
 Start Parameters, ExtensionPoint
 Hibernate
 switched from CommonsLogging to SLF4J
74

Compare LogFrameworks
75

HowTo integrate them all
 SLF4JoverOSGI Bridge
 SLF4J with logback implementation
 catches JCL, JDK, SLF4J, OSGI Log, ext. Log
 Marker and Bundles
 Fragments
 alternate Solution: PAX Logging
 Log4J
 catches JCL, JDK, SLF4J, Avalon
76

HowTo integrate them all
77

HowTo solve Dependency Cycles
 Eclipse 3.4
 PDE Export has Problems with Cycles
 Equinox Runtime works well
 Trick:
 put a „Fake“ Bundle without Dependencies into Workspace
78

HowTo solve Dependency Cycles
 Eclipse 3.5M6 PDE Tooling Support
 dont forget to set Compiler Warnings:
79

Classloader from 3rd party
 EasyBeans contains Hibernate
 Hibernate uses ContextClassLoader
 Try to avoid
 Dynamic Import *
 BuddyPolicy only if really needed
80

HowTo configure the TargetPlatform (1)
 Overview
 TargetPlatformDefinition Files
 to be portable: variable - string substitution
 PDE Tooling 3.5 easier
 Duplicates, Deltas
 Bugzilla Reports discuss better PDE Tooling support
82

HowTo configure the TargetPlatform (2)
 Locations
83

HowTo configure the TargetPlatform (3)
84

HowTo configure the TargetPlatform (3)
84

oAW - your little Helper
 EZB, Hibernate Bug Annotations
 generate classnames into persistence.xml
 Check JPA Persistence data
 length of indizes, tables, inheritance strategies
 EZB problems JNDI naming
 generate mapped Names into Interfaces
 Bridge between UML and EMF
 from UML to EMF - UI and back
85

oAW - solves Bug detecting Entity
 generate classnames into persistence.xml
86

oAW - solves Bug injecting @EJB (1)
 generate @EJB.mappedName
87

oAW - solves Bug injecting @EJB (2)
 generate @EJB.mappedName
88

oAW - solves Bug injecting @EJB (3)
 generate @EJB.mappedName
 now its easy to use:
@EJB (mappedName = MyInterface.EZB_MAPPED_NAME)
MyInterface mi = null;
89

Summary
 Server
 Equinox (OSGI Framework), Riena (OSGI RemoteServices)
 EasyBeans (OSGI EJB3 Container, JPA, Hibernate)
 Rich Client
 Eclipse RCP, Riena (UI Ridgets and Navigation)
 Riena (OSGI Remote Services, ObjectTransactions)
 ModelDriven Project
 Eclipse Modeling (EMF, UML, CDO)
 openArchitectureWare (oAW): Workflow, XPand, Xtend
 MagicDraw (UML, DSL, oAW Integration)
90

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Next Steps
 Other ways to persist ?
 More M2M Transformations
 Give Value back to Open Source Community
94

Alternate Ways to Persist Data
 EasyBeans and EclipseLink
 EasyBerans provides both: Hibernate + EclipseLink
 CDO with Teneo Hibernate
 re-use of JPA Annotations for Teneo
 EMF Databinding
 CDO remoting instead of RienaRemoteOSGI
 possible ????
95

Extra M2M transformation
 whole Business Model as EMF
 extra M2M transformation from UML
 pro:
 redView Drag‘n‘Drop for Databinding
 needed if CDO in the future becomes an alternative
96

97

open-erp-ware.org (1)
 Open Source OSGI - EJB3 - Riena Server
 core equinox-EasyBeans OSGI-EJB3 server
 UML Profiles (Java, JPA, EJB3, Drools)
 oAW Templates and Cartridges
 MagicDraw DSL Customization + Editors
 Riena for Remote OSGI Services
 plus core ERP functionality (business modules)
 first beta published in june 2009
98

open-erp-ware.org (2)
 slf4joverOSGI
 LoggingBridge
 could be used additional to SLF4J / LogBack Bridges
99

redView - Riena EMF Dynamic Views
 Open Source Dynamic Views for Business Applications
 EMF
 CDO
 Ridgets
 Prototyping
 WYSIWYG Editor for dynamic SWT Views
100

Question & Answer
 ekke@ekkes-corner.org
 Blog: http://ekkes-corner.org (en)
 Blog: http://ekkes-ecke.org (de)
 Video Podcasts: http://ekkes-corner-tv.org
 Twitter: @ekkescorner
 http://open-erp-ware.org
 http://redview.org
101

Video Podcast
 you like to watch and hear this screencast as a
Video Podcast ?
 visit: http://ekkes-corner-tv.org
 or search iTunes for „ekkes-corner“
 (c) 2009 ekkehard gentz, eclipse public license EPL
102