OSGi & Java Modularity

Transcription

1 OSGi & Java Modularity Jazoon 2009, Zürich by Peter Kriens

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5 Productivity Application Complexity

6 Productivity Assembly Application Complexity

7 Productivity Structured Programming Assembly Application Complexity

8 Productivity Structured Programming Object Oriented Programming Assembly Application Complexity

9 Productivity Service Oriented Programming? Structured Programming Object Oriented Programming Assembly Application Complexity

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11 Application

12 Extensions Application Application Convenience Foundation Basic Something Core Java VM

13 minilang party pos. product workeffort workflow accounting assetmaint content Extensions bi ebay ecommerce googlebase guiapp hhfacility manufact. marketing minerva oagis order common catalina base Application layer Application datafile entity widget Application mail mx4j naming jetty poi resolver rome serializer servlets tomcat jenks jpos18 jython looks lucene Foundation Basic jakarta jcl json jdbm jdom xalan Convenience wsdl4j xerces Something xmlapis bsf bsh velocity ws-commons log4j barcode4j axis batik commons httpunit freemarker ezmorph fop derby Core xmlrpc xmlgraphics geronimo Libs.. Java VM Java VM rt jce jsse plugin sunjce_prov. dnsns..

14 minilang party pos. product workeffort workflow accounting assetmaint content Extensions bi ebay ecommerce googlebase guiapp hhfacility manufact. marketing minerva oagis order common catalina base Application layer Application datafile entity widget Application mail mx4j naming jetty poi resolver rome serializer servlets tomcat jenks jpos18 jython looks lucene Foundation Basic jakarta jcl json jdbm jdom xalan Convenience wsdl4j xerces Something xmlapis bsf bsh velocity ws-commons log4j barcode4j axis batik commons httpunit freemarker ezmorph fop derby Core xmlrpc xmlgraphics geronimo Libs.. Java VM Java VM rt jce jsse plugin sunjce_prov. dnsns..

15 by Damoiselle de Pique

16 Was Pollock an Early OO Programmer? by Damoiselle de Pique

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18 modularity

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24 low coupling,

25 low coupling, high cohesion &

26 low coupling, high cohesion & encapsulation

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28 How Do We Handle This Complexity in Java?

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30 Visibility vs Accessibility

31 Visibility Class S Class T

32 Visibility Class S Class T

33 Visibility Class S Class T

34 Visibility Class S Class T

35 Visibility Class S Module System Class T

36 Hierarchical Class Loaders boot ext app app cust

37 Hierarchical Class Loaders boot ext app app visibility cust

38 Context Class Loaders boot X {} ext app app Y {} cust

39 Context Class Loaders boot X {} ext Thread -> Context ClassLoader app app Y {} cust

40 Context Class Loaders boot X {} ext Thread -> Context ClassLoader app app Y {} cust

41 Accessibility public module package private

42 Accessibility Class V module Class W Class S Class T class Class U package

43 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.. Begin Here

44 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.. Class Not Found Exception Begin Here

45 Split Packages JARs A 2 B C import private export

46 Split Packages JARs A package com.foo: X, Y 2 B package com.foo: X, Y, Z C package com.foo: X, Y, Z import private export

47 Split Packages JARs A package com.foo: X, Y 2 B package com.foo: X, Y, Z C package com.foo: X, Y, Z import private export

48 Split Packages JARs A package com.foo: X, Y 2 B package com.foo: X, Y, Z C package com.foo: X, Y, Z import private export

49 Versioning JARs A package com.foo: X, Y 2 B package com.foo: X, Z C package com.foo: X, Y, Z import private export

50 Versioning JARs A package com.foo: X, Y package com.bar: A,B,C;1.0 2 B package com.foo: X, Z package com.bar: A;2.0 C package com.foo: X, Y, Z package com.bar: A,B,C;2.0 import private export

51 Versioning JARs A package com.foo: X, Y package com.bar: A,B,C;1.0 2 B package com.foo: X, Z package com.bar: A;2.0 C package com.foo: X, Y, Z package com.bar: A,B,C;2.0 import private export

52 Private Packages JARs A package com.foo: X, Y package com.bar: A,B,C;1.0 2 B package com.foo: X, Z package com.bar: A;2.0 C package com.foo: X, Y, Z package com.bar: A,B,C;2.0 import private export

53 Private Packages JARs A package com.foo: X, Y package com.bar: A,B,C;1.0 2 B package com.foo: X, Z package com.bar: A;2.0 package com.private: G C package com.foo: X, Y, Z package com.bar: A,B,C;2.0 package com.private: G,H,I import private export

54 Private Packages JARs A package com.foo: X, Y package com.bar: A,B,C;1.0 2 B package com.foo: X, Z package com.bar: A;2.0 package com.private: G C package com.foo: X, Y, Z package com.bar: A,B,C;2.0 package com.private: G,H,I import private export

55 How Do We Handle This Complexity in Java?

56 We Don t...

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59 Applications (bundles) Service Life Cycle Module S E C U R I T Y Execution Environment OS + Hardware

60 Execution Environment

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62 CLDC/ MIDP OSGi Min. CDC/FP J2SE 1.3, 1.4, 5, 6,...

63 Kim Scarborough

64 Module Layer

65 Import, Export, Private Bundle A Bundle B p q-1.4 Bundle A r p q-[1.2,1.8) r. import private export

66 Import, Export, Private Bundle A Bundle B p q-1.4 Bundle A r imports p q-[1.2,1.8) r. import private export

67 Import, Export, Private Bundle A Bundle B p q-1.4 Bundle A r imports exports p q-[1.2,1.8) r. import private export

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70 Uses Constraints Bundle A Bundle B r;1.0 p q-1.4 r;2.0 p q-[1.2,1.8) Bundle C Bundle D r;1.0 r;2.0 import private export

71 Uses Constraints Bundle A Bundle B r;1.0 p q-1.4 imports r;2.0 p q-[1.2,1.8) Bundle C Bundle D r;1.0 r;2.0 import private export

72 Uses Constraints Bundle A Bundle B r;1.0 p q-1.4 imports exports r;2.0 p q-[1.2,1.8) Bundle C Bundle D r;1.0 r;2.0 import private export

73 Uses Constraints Bundle A Bundle B r;1.0 p q-1.4 imports exports r;2.0 p q-[1.2,1.8) Bundle C Bundle D r;1.0 r;2.0 import private export

74 System Loader Extension Loader Application B Loader Custom Loader

75 System Loader Extension Loader Application B Loader OSGi Custom Loader

76 System Loader Bundle A Extension Loader Bundle G Bundle B Application B Loader Framework Loader OSGi Bundle C Custom Loader Bundle F Bundle E Bundle D

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78 Life Cycle Layer

79 INSTALLED STARTING RESOLVED ACTIVE UNINSTALLED STOPPING

80 System bundle MANAGE- MENT BUNDLE Bundle X-v2 X Bundle A Bundle B

81 Service Layer

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86 Services defined in interface/class Bundle A register get Bundle B notify

87 Services void foo() { } interface Foo { void foo(); } s.foo()

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93 Services Solve Class Loader Problems!

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95 Security

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97 Real Code!

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99 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: 1.0 Bundle-Activator: com.acme.helloworld Import-Package: org.osgi.framework;version=1.3

100 Bundles are active entities in runtime

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102 294

103 294 7

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106 Is JSR 294 a Meta Module System? (Implemented by OSGi, Jigsaw, Guice, )

107 Is JSR 294 a Meta Module System? (Implemented by OSGi, Jigsaw, Guice, ) No Java Standard for Modules!

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111 Legacy

112 Class.forName

113 Class.forName

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115 Bloat?

116 Accidental Complexity

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121 bundle A-1.2 b c bundle B-4.1 a bundle C-1.0

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124 The Component Framework

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126 Q&A

127 Thanks!