Lecture 18 Introduction to Components

Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and Iterative Development (3rd Edition)

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Copyright W. Howden 1 Lecture 19: Intro to O/O Components
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Copyright W. Howden 2 O/O Components • A computational unit that exposes a well defined, contractual interface – constructed from a set of one or more classes • Sample components – Applets, Servlets, Java Beans, Enterprise Java Beans
Background image of page 2
Copyright W. Howden 3 O/O World Dream • Goal: objects everywhere • To get something done, send a message to the appropriate kind of object • Problems – how to find objects, how to communicate – sharing, persistency, load balancing, transactions
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Copyright W. Howden 4 Distributed O/O Objects – Simple Early Models • RMI (Java), Corba, Com • RMI – register remote objects with a public name – create stub and skeleton proxies that are network savvy • Limited facilities for persistency, sharing, transactions, remote creation
Background image of page 4
Copyright W. Howden 5 Bean Components • Java Beans – “ A reusable software component based on the JB’s specification that can be manipulated visually in a builder tool.” • Enterprise Java Beans – “A set of contracts between the component developer and the system that hosts the component.”
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Copyright W. Howden 6 Additional Component Aspects • Deployable – loaded into a container in which they can run – linked together to build a system • Runs in a “container” that supplies services need for running and managing the components • Distributable, with remote invocation via a specified interface
Background image of page 6
Copyright W. Howden 7 Servlet Components • compiled Java classes with special methods • run on a request/response oriented server – request (possibly with data) arrives at server – servlet is run to generate response that is returned
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 27

Lecture 18 Introduction to Components - Lecture 19: Intro...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online