OSGi and Java Modularity

OSGi &Java Modularity

Jazoon 2009, Zürich

by Peter Kriens

donderdag 25 juni 2009

Prod

uctiv

ity

Application Complexity


Prod

uctiv

ity


Assembly


Prod

uctiv

ity


Assembly

Structured Programming


Prod

uctiv

ity


Assembly


Object Oriented Programming


Prod

uctiv

ity


Assembly


Object Oriented Programming

Service Oriented Programming?


Application


Application

Extensions

Application

Foundation

Java VM

Basic

Convenience

Something

Core


Application

Extensions

Application

Foundation

Java VM

Basic

Convenience

Something

CoreJava VM

log4j barcode4j axis batik commons

derbyfopezmorphfreemarkerhttpunit

jakarta jcl json jdbm jdom

jenks jpos18 jython looks lucene

mail mx4j naming jetty poi

resolver rome serializer servlets tomcat

velocity

ws-commons

xalan

wsdl4j

xerces

xmlgraphics

xmlrpc

xmlapis

..

geronimo

bsh

bsf

guiapp hhfacility manufact. marketing minerva

accounting assetmaint

base

bi

catalinacommon

oagis order

ebaycontent

datafile

ecommerce

entity

googlebase

Application layer

widget

minilang party pos. product workeffort workflow …

sunjce_prov.pluginjssejcert dnsns ..

…

Libs


by Damoiselle de Pique


by Damoiselle de Pique

Was Pollock an Early OOProgrammer?


modularity


low coupling,


low coupling,high cohesion &


low coupling,

encapsulationhigh cohesion &


How Do WeHandle ThisComplexity

in Java?


Visibilityvs

Accessibility


Visibility

ClassS

ClassT

ClassT


Visibility

ClassS

ClassT


Visibility

ClassS

ClassT

ModuleSystem


Hierarchical Class Loaders

ext

app app

cust

boot


Hierarchical Class Loaders

ext

app app

custvisibility

boot


Context Class Loaders

ext

boot

app app

cust

X {}

Y {}


Context Class Loaders

ext

boot

app app

cust

X {}

Y {}

Thread -> ContextClassLoader


Accessibility

public

package

module

private


module

package

class

Accessibility

ClassS

ClassT

ClassW

Class U

ClassV


Java VM

log4j

barcode4j

axis

batik

commons

derby

fop

ezmorph

freemarker

httpunit

jakarta

jcl

json

jdbm

jdom

jenks

jpos18

jython

looks

lucene

mail

mx4j

naming

jetty

poi

resolver

rome

serializer

servlets

tomcat

velocity

ws-commons

xalan

wsdl4j

xerces

xmlgraphics

xmlrpc

xmlapis

..

geronimo

bsh

bsf

guiapp

hhfacility

manufact.

marketing

minerva

accounting

assetmaint

base

bi

catalina

common

oagis

order

ebay

content

datafile

ecommerce

entity

googlebase

ofbiz

widget

minilang

party

pos.

product

workeffort

workflow

…

sunjce_prov.

plugin

jsse

jce

rt

dnsns

..

…

BeginHere


Java VM

log4j

barcode4j

axis

batik

commons

derby

fop

ezmorph

freemarker

httpunit

jakarta

jcl

json

jdbm

jdom

jenks

jpos18

jython

looks

lucene

mail

mx4j

naming

jetty

poi

resolver

rome

serializer

servlets

tomcat

velocity

ws-commons

xalan

wsdl4j

xerces

xmlgraphics

xmlrpc

xmlapis

..

geronimo

bsh

bsf

guiapp

hhfacility

manufact.

marketing

minerva

accounting

assetmaint

base

bi

catalina

common

oagis

order

ebay

content

datafile

ecommerce

entity

googlebase

ofbiz

widget

minilang

party

pos.

product

workeffort

workflow

…

sunjce_prov.

plugin

jsse

jce

rt

dnsns

..

…

ClassNot

FoundException

BeginHere


import exportprivate

A

B

C

JARs

2

Split Packages


package com.foo: X, Y

package com.foo: X, Y, Z


A

B

C

JARs


2

Split Packages




2package com.foo: X, Z


A

B

C

JARs

Versioning




2

package com.bar: A,B,C;2.0


package com.bar: A;2.0

package com.foo: X, Z


A

B

C

JARs

Versioning




2






A

B

C

JARs

Private Packages




2





package com.private: G

package com.private: G,H,I


A

B

C

JARs

Private Packages


How Do WeHandle ThisComplexity

in Java?


We Don’t ...


OS + Hardware

Execution Environment

Module

Life Cycle

Service

SECURITY

Applications(bundles)


Execution Environment


CLDC/MIDP

J2SE 1.3, 1.4,

5, 6, ...CDC/FP

OSGiMin.


Kim Scarborough


Module Layer


Import, Export, Private

Bundle A

Bundle B

.

p

r

q-[1.2,1.8)

p

q-1.4

import export

r

private

Bundle A



Bundle A

Bundle B

.

p

r

q-[1.2,1.8)

p

q-1.4

import

imports

export

r

private

Bundle A



Bundle A

Bundle B

.

p

r

q-[1.2,1.8)

p

q-1.4

import

imports

exports

export

r

private

Bundle A


Uses ConstraintsBundle B

q-[1.2,1.8)

p

q-1.4

Bundle A

Bundle DBundle C

r;2.0r;1.0

r;2.0r;1.0

p




q-[1.2,1.8)

p

q-1.4

imports

Bundle A

Bundle DBundle C

r;2.0r;1.0

r;2.0r;1.0

p




q-[1.2,1.8)

p

q-1.4

imports

exports

Bundle A

Bundle DBundle C

r;2.0r;1.0

r;2.0r;1.0

p



SystemLoader

ExtensionLoader

Application BLoader

CustomLoader


SystemLoader

ExtensionLoader

Application BLoader

CustomLoader

OSGi


SystemLoader

ExtensionLoader

FrameworkLoader

Application BLoader

CustomLoader

Bundle G

Bundle C

Bundle A

Bundle B

Bundle F

Bundle E

Bundle D

OSGi


Life Cycle Layer


INSTALLED

RESOLVED

UNINSTALLED

ACTIVE

STOPPING

STARTING


BundleX

BundleX-v2

BundleB

MANAGE-MENT

BUNDLE

BundleA

Systembundle


Service Layer


Services

BundleA

BundleB

register get

notify

defined ininterface/class


Services

void foo() {…}

…s.foo()…

interface Foo { void foo();}


Services Solve Class Loader

Problems!donderdag 25 juni 2009

Security


Real Code!


package com.acme;import org.osgi.framework.*;public class HelloWorld extends BundleActivator { public void start(BundleContext context) { System.out.println(“Hello World”); } public void stop(BundleContext context) { System.out.println(“Goodbye World”); }}

---------------------------------------------

Manifest: 1.0Bundle-Activator: com.acme.HelloWorldImport-Package: org.osgi.framework;version=1.3


Bundles are active entities in runtime


294


2947


Is JSR 294 aMeta Module System? (Implemented by OSGi™, Jigsaw, Guice, …)


Is JSR 294 aMeta Module System? (Implemented by OSGi™, Jigsaw, Guice, …)

No Java™ Standard for

Modules!donderdag 25 juni 2009

Legacy


Class .forName


Bloat?donderdag 25 juni 2009

AccidentalComplexity


‘97 ‘98 ‘99 ‘00 ‘01 ‘02 ‘03 ‘04 ‘05 ‘06 ‘07 ‘08 ‘09 ‘10


bundleA-1.2

bundleB-4.1

bundleC-1.0

bc

a


The ComponentFramework


Q&Adonderdag 25 juni 2009

Thanks!


OSGi and Java Modularity

Design

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