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This chapter include objectives: Define information technology (IT) and its two basic categories: hardware and software; describe the categories of computers based on size; compare the roles of personal productivity, vertical market, and horizontal market software; describe the roles of operating system and utility software as components of system software; define the purpose of each of the six major categories of hardware. | Lecture 23 Enterprise Systems Development ( CSC447) COMSATS Islamabad Muhammad Usman, Assistant Professor College of Statistical and Acturial Science Communication Protocol Models Remote Procedure Call (RPC) Since 1980s, pioneered by Sun Tears of testing with various communication models Distributed extension of MS COM (DCOM) Lets COM talk to other platforms Complex configuration and complicated security model Remote Method Invocation (RMI) Communication between methods of Java classes Drawbacks of RPC/RMI approach? Platform-specific, procedural and low-level The JavaBeans API “A Java Bean is a reusable software component that can be manipulated visually in a builder tool.” JavaBeans API makes it possible to write component software in Java Components are self-contained, reusable software units that can be visually composed into composite components, applets, applications, and servlets using visual application builder tools. JavaBean components are known as Beans. Components and Software Architecture Classes vs. components: class hierarchies + object collaboration = detailed design components + collaboration = architecture Class vs. JavaBean: Class == a brick, a piece of wood, a nail Javabean = a wall element, a roof, a room Client application == a building An architecture does not concentrate on nails and bricks! Sample Reusable Components Button Beans Slider Bean An application constructed from Beans JavaBeans made out of Java classes Beans are classes that can be manipulated in a visual builder tool and composed into apps. Any Java class that adheres to certain conventions regarding property and event interface definitions can be a JavaBean. Beans publish their attributes and behaviors through special method signature patterns that are recognized by beans-aware application construction tools. Builder Tools and Properties Discover Bean’s Properties Determine properties’ read/write attributes Determine property types Locate property editors Display property | Lecture 23 Enterprise Systems Development ( CSC447) COMSATS Islamabad Muhammad Usman, Assistant Professor College of Statistical and Acturial Science Communication Protocol Models Remote Procedure Call (RPC) Since 1980s, pioneered by Sun Tears of testing with various communication models Distributed extension of MS COM (DCOM) Lets COM talk to other platforms Complex configuration and complicated security model Remote Method Invocation (RMI) Communication between methods of Java classes Drawbacks of RPC/RMI approach? Platform-specific, procedural and low-level The JavaBeans API “A Java Bean is a reusable software component that can be manipulated visually in a builder tool.” JavaBeans API makes it possible to write component software in Java Components are self-contained, reusable software units that can be visually composed into composite components, applets, applications, and servlets using visual application builder tools. JavaBean components are known as Beans. Components and
