Downloaded 170 times
![Version Ranges
Open, closed or implicit
[1.0.0, 2.0.0] ! 1.0.0 ! version ! 2.0.0
[1.0.0, 2.0.0) ! 1.0.0 ! version < 2.0.0
Informally “1.*”
1 ! [1.0.0, ")
Unspecified ! [0.0.0, ")](https://image.slidesharecdn.com/jjugintrotoosgi-091227061946-phpapp01/85/Introduction-to-OSGi-Tokyo-JUG-27-320.jpg)
![Starting Point...
import javax.sql.DataSource;
public class DbMailbox implements Mailbox {
private DataSource dataSource;
void setDataSource(DataSource ds) { /*...*/ }
void unsetDataSource(DataSource ds) { /*...*/ }
public long[] getAllMessages() {
// ...
}
}](https://image.slidesharecdn.com/jjugintrotoosgi-091227061946-phpapp01/85/Introduction-to-OSGi-Tokyo-JUG-86-320.jpg)
![Starting Point...
No OSGi API Used
import javax.sql.DataSource;
public class DbMailbox implements Mailbox {
private DataSource dataSource;
void setDataSource(DataSource ds) { /*...*/ }
void unsetDataSource(DataSource ds) { /*...*/ }
public long[] getAllMessages() {
// ...
}
}](https://image.slidesharecdn.com/jjugintrotoosgi-091227061946-phpapp01/85/Introduction-to-OSGi-Tokyo-JUG-87-320.jpg)
![Starting Point...
No OSGi API Used
import javax.sql.DataSource;
public class DbMailbox implements Mailbox {
private DataSource dataSource;
void setDataSource(DataSource ds) { /*...*/ }
void unsetDataSource(DataSource ds) { /*...*/ }
public long[] getAllMessages() {
// ...
}
} JavaBeans Style => Testable](https://image.slidesharecdn.com/jjugintrotoosgi-091227061946-phpapp01/85/Introduction-to-OSGi-Tokyo-JUG-88-320.jpg)
![Make it a Component
import javax.sql.DataSource;
@Component
public class DbMailbox implements Mailbox {
private DataSource dataSource;
@Reference(service = DataSource.class)
void setDataSource(DataSource ds) { /*...*/ }
void unsetDataSource(DataSource ds) { /*...*/ }
public long[] getAllMessages() {
// ...
}
}](https://image.slidesharecdn.com/jjugintrotoosgi-091227061946-phpapp01/85/Introduction-to-OSGi-Tokyo-JUG-89-320.jpg)
More Related Content
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Introduction to OSGi (Tokyo JUG)
- 1. Introduction to OSGi NeilBartlett – 2009 12 23
- 2. ❶ Brief Intro toOSGi
- 3. OSGi: The Module Systemfor Java
- 4. Standard Java JARs areDeployment Units ABC.JAR They are Not Modules
- 5. What’s Missing? Meaningful name Version Vendor ABC.JAR Exports Dependencies
- 6. Dependencies JARs do havedependencies They are implicit. A dependency is an assumption. “I assume module X (version Y) is on the classpath. If not I will crash and burn.”
- 7.
- 8. Just a JAR+ Metadata Meaningful name Version Vendor org.foo.mylib Manifest-Version: 1.0 Exports Bundle-SymbolicName: com.mylib Bundle-Name: My Library Bundle Bundle-Vendor: Neil Bartlett Bundle-Version: 1.0.0 Import-Package: javax.swing, org.w3c.dom Export-Package: com.mylib1.ui;version=“1.0.0”, com.mylib1.util;version=“1.0.0” Bundle-RequiredExecutionEnvironment: J2SE-1.5 Dependencies
- 9. MANIFEST.MF Manifest-Version: 1.0 Bundle-SymbolicName: com.mylib Bundle-Name:My Library Bundle Bundle-Vendor: Neil Bartlett Bundle-Version: 1.0.0 Import-Package: javax.swing, org.w3c.dom Export-Package: com.mylib.ui;version=“1.0.0”, com.mylib.util;version=“1.0.0” Bundle-RequiredExecutionEnvironment: J2SE-1.5
- 10.
- 11.
- 13. Imports..... and Exports } { com.foo.bar com.mylib javax.swing com.mylib.ui org.wibble com.mylib.util
- 14. Package Resolution com.foo.bar A
- 15. Package Resolution com.foo.bar com.foo.bar B A
- 16. Package Resolution com.foo.bar com.foo.bar B A
- 17. Versioned Dependency com.foo.bar [1.2.0,1.4.0) A
- 18. Versioned Dependency com.foo.bar com.foo.bar B 1.4.5 [1.2.0,1.4.0) A
- 19. Versioned Dependency B com.foo.bar 1.4.5 ✘ com.foo.bar [1.2.0,1.4.0) A
- 20. Versioned Dependency com.foo.bar com.foo.bar B’ 1.3.12 [1.2.0,1.4.0) A
- 21. Versioned Dependency com.foo.bar com.foo.bar B’ 1.3.12 [1.2.0,1.4.0) A
- 22. Side-by-Side Versions com.foo.bar com.foo.bar B X 1.4.5 [1.4.0,1.5.0) com.foo.bar com.foo.bar B’ Y 1.3.12 [1.2.0,1.4.0)
- 23. Side-by-Side Versions com.foo.bar com.foo.bar B X 1.4.5 [1.4.0,1.5.0) com.foo.bar com.foo.bar B’ Y 1.3.12 [1.2.0,1.4.0)
- 24. How it Works Bundle-SymbolicName:com.mylib1 Bundle-Version: 1.2.0 Export-Package: com.mylib1.ui;version=“1.2.0”, com.mylib1.util;version=“1.2.0” Bundle-SymbolicName: com.app1 Bundle-Version: 2.2.3.alpha Import-Package: com.mylib1.ui;version=“[1.2.0,1.3.0)” com.mylib1.util;version=“[1.2.0,1.3.0)”
- 25. Private Internals Exports mustbe stated explicitly Packages not listed in “Export-Package” are not available to other bundles
- 26. Versions Standard numbering schemewith well-defined ordering. major.minor.micro.qualifier First three numeric, last alphanumeric Eg 1.0.0.beta2 Unspecified ! 0.0.0
- 27. Version Ranges Open, closedor implicit [1.0.0, 2.0.0] ! 1.0.0 ! version ! 2.0.0 [1.0.0, 2.0.0) ! 1.0.0 ! version < 2.0.0 Informally “1.*” 1 ! [1.0.0, ") Unspecified ! [0.0.0, ")
- 28. Our Promise*: NoMore NoClassDefFoundErrors!
- 29.
- 30. Dynamic Install Bundles Update Bundles UninstallBundles ... all “on the fly”
- 31.
- 32. OSGi is theKing of Infrastructure All Major JEE Application Servers use OSGi Most ESBs use OSGi 2 of 3 Open Source IDEs use OSGi Even Build Tools (Maven and Hudson) Moving to OSGi
- 33.
- 34. OSGi for Applications UntilRecently, Application Servers used OSGi “on the inside” Now SpringSource dm Server, Paremus Infiniflow, WAS 7, GlassFish v3 and WebLogic DM all expose OSGi Application Developers can Finally Deploy OSGi bundles to their OSGi servers!
- 35. Why is OSGiAttractive for Application Development?
- 36. ❸ The Failure ofObject Oriented Programming
- 37. OOP Was Meantto Enable Reuse
- 38.
- 39. “Building a newsystem would be a snap. Just get a few classes, bunch them together... and voila!” – Peter Kriens
- 40.
- 41.
- 42.
- 43. Classes coupled to OtherClasses
- 44. Packages coupled to OtherPackages
- 45.
- 46. JARs coupled toMore JARs
- 47. Which are coupledto yet more JARs...
- 49.
- 50. DI Frameworks Provide “LateBinding” of Implementations to Interfaces But Not Late Enough!
- 51. Spring Framework <bean id="MyBean"class="org.example.MyBean"> <property name="dataSource" ref="OracleDataSource"/> </bean> <bean id="OracleDataSource" class="..."> <property name="..." /> </bean>
- 52.
- 53. Static DI “Beans” arewired together once, at start-up They cannot be rewired Limited support for optional dependencies
- 54.
- 55.
- 56. Reuse is Hard,So Don’t Try!
- 57. Leave Code inOne Place, and Call Remotely (...also known as “SOA”)
- 58.
- 59.
- 60.
- 61.
- 62. Not Really... Dead Lumpsof Plastic Many Copies of the Same Thing
- 63.
- 64.
- 65. Dr Alan Kay Inventorof Object Oriented Programming & Smalltalk “I thought of objects being like biological cells...”
- 66. Components Do Something, orProvide Something Aware of and Adapt to their Environment Have a Life-cycle (birth to death).
- 67. “Do” Something Open asocket Monitor a device Poll a queue Display a GUI .... etc.
- 68. “Provide” Something Publish aService – may be used by other components
- 69. The “Environment” The “Environment”of a Component means: Services provided by other Components Resources, Devices, Network etc
- 70. Components Adapt to theirEnvironment
- 71. Good Environment Most servicesare available The component flourishes
- 72. Harsh Environment Some non-essentialservices are unavailable Component adapts and survives
- 73. Very Harsh Environment Essentialservices are unavailable Component hibernates or dies
- 74. Composition Components Use otherComponents In this way, whole Systems are Composed Resilient, Elastic Systems
- 75.
- 76. Services Components provide Services Registeredwith a Service Registry Services are POJOs! Looked up by Java interface name
- 77. In-Process SOA Service Broker Find Register Service Contract Service Service Provider Consumer Client Bind Service
- 78. Plain Old JavaObjects
- 79.
- 80.
- 81. We Don’t CodeDirectly against Services (it’s too hard!)
- 82. Let a Framework Handlethe Hard Stuff
- 83. Choice of Frameworks DeclarativeServices (DS) Blueprint (from Spring-DM) iPOJO Guice Peaberry
- 84. Framework Interop Perfect Interoperabilityof these Frameworks! No need to choose “The One True Framework” Use 3rd-party components implemented with other frameworks.
- 85. Examining DS Dynamic dependencyinjection (DI) ... and “uninjection”
- 86. Starting Point... import javax.sql.DataSource; publicclass DbMailbox implements Mailbox { private DataSource dataSource; void setDataSource(DataSource ds) { /*...*/ } void unsetDataSource(DataSource ds) { /*...*/ } public long[] getAllMessages() { // ... } }
- 87. Starting Point... No OSGi API Used import javax.sql.DataSource; public class DbMailbox implements Mailbox { private DataSource dataSource; void setDataSource(DataSource ds) { /*...*/ } void unsetDataSource(DataSource ds) { /*...*/ } public long[] getAllMessages() { // ... } }
- 88. Starting Point... No OSGi API Used import javax.sql.DataSource; public class DbMailbox implements Mailbox { private DataSource dataSource; void setDataSource(DataSource ds) { /*...*/ } void unsetDataSource(DataSource ds) { /*...*/ } public long[] getAllMessages() { // ... } } JavaBeans Style => Testable
- 89. Make it aComponent import javax.sql.DataSource; @Component public class DbMailbox implements Mailbox { private DataSource dataSource; @Reference(service = DataSource.class) void setDataSource(DataSource ds) { /*...*/ } void unsetDataSource(DataSource ds) { /*...*/ } public long[] getAllMessages() { // ... } }
- 90. Annotations @Component – Createa Component of this type. Service is automatically published @Reference – Use the specified service
- 91. Add Life-cycle @Activate void start(){ thread = new Thread(); thread.start(); } @Deactivate void stop() { thread.interrupt(); }
- 92. Make it Configurable @Activate voidstart(Map<String, Object> configuration) { thread = new Thread(); thread.start(); } @Modified void modify(Map<String, Object> newConfiguration) { // This method is optional } @Deactivate void stop() { thread.interrupt(); }
- 93. Optional Reference @Reference(service =LogService.class, optional = true) void setLogService(LogService log) { /* ... */ } void unsetLogService(LogService log) { /* ... */ }
- 94. Multiple Reference @Reference(service =MailboxListener.class, multiple = true) void addListener(MailboxListener listener) { /* ... */ } void removeListener(MailboxListener listener) { /* ... */ }
- 95.
- 96. Mailbox Reader Mailbox Fixed Mailbox
- 97. Mailbox Reader MailboxListener Mailbox Growing Mailbox
- 98. Mailbox Reader MailboxListener Mailbox Trades Order Entry Mailbox Matching EventHandler Service Trade Matching Event Broker Engine EventAdmin