page 1, june 1, 2015 cbse – graduate course an introduction to different component technologies...

, April 18, 2023CBSE – graduate course

An Introduction to An Introduction to Different Different

Component TechnologiesComponent Technologies

Magnus Larsson


Different TechnologiesDifferent Technologies

XML

IEC 6 1131-3

COM

EJB

CORBA

SOAP

.NET

Blackbox


Slide 1

An Introduction to CORBAAn Introduction to CORBA

Magnus [email protected]


Focus on swiftly-developed, easily usable (“off the shelf”) component standards.

OMG’s MissionOMG’s Mission

Develop a single architecture, using object technology, for distributed application integration, guaranteeing:

reusability of components;

interoperability & portability;

basis in commercially available software.HOW?


OMG: BackgroundOMG: Background

Not-for-profit company based in United States, with representation in United Kingdom, Germany, Japan, Australia & India.

Founded April 1989.

Small staff (35 full time); no internal development.

Sponsors Object World conference and DOC magazine to help spread the word.

Dedicated to creating and popularizing object-oriented standards for application integration based on existing technology.


The OMA GuideThe OMA Guide

Outlines the Object Management Architecture, contains foundation of standards including:

Overview of integration problem, with reasons for object-oriented solution.

Objectives of the standards group.

Abstract object model.

Reference model (architecture).

Glossary of terms.


CORBA (Common Object Request Broker Architecture)

CORBAapps CORBAdomains CORBAfacilities

CORBAservices

OMA OverviewOMA Overview

TransactionsTransactions EventEvent SecuritySecurity NamingNaming


CORBACORBA

Common Object Request Broker Architecture

Standard for writing distributed object systems

Language independent

Not controlled by one company

Optional value added services

Slow moving

Steep learning curve

Different CORBA products may be incompatible


Enterprise Java BeansEnterprise Java Beans

Magnus Larsson

[email protected]


BackgroundBackground

Early 90s

Shift from two-tier, client-server application model to more flexible three-tier and multi-tier application models.

The new models separated business logic from system services and the user interface,

Placing it in a middle tier between the two.

middleware services

transaction monitors, message-oriented middleware, object request brokers

a greater emphasis on lightweight, easy to deploy clients.


Introducing EJBIntroducing EJB

Used to build business systems

Server side components

Highly available (24x7)

Fault tolerant

Transactional

Multi-user secure environment


J2EEJ2EE

Java 2 Platform Enterprise Edition

Development platformPortable

Multi-user

Secure

EJB is a cornerstone in J2EE

Is a specification, not a product


J2EE TechnologiesJ2EE Technologies

Enterprise JavaBeans (EJB)

Java Remote Method Invocation (RMI)

Java Naming and Directory Interface (JNDI)

Java Database Connectivity (JDBC)

Java Transaction API and Service (JTA & JTS)

Java Servlets and Java Server Pages (JPS)

Java IDL - Sun’s implementation of CORBA

...


An Introduction to COMAn Introduction to COM


Introducing COMIntroducing COM

Coming from OLE (Object linking and embedding)

Microsoft’s Component Object Model (COM) was the first component model.

Distributed COM (DCOM) allows creating and accessing COM objects on another machine (1996 with NT 4).

Allows component communication


Availability of COMAvailability of COM

Windows and Macintosh

Software AG, Compaq and others supports DCOM on several UNIX platforms.

The main COM market is focused on Windows.


A Simple COM ObjectA Simple COM Object

A COM object has methods and state

Language independent

All Access is through the interface

Supports multiple interfaces


Specifying InterfacesSpecifying Interfaces

COM defines a binary standard for interfaces

Language independent implementation of the interfaces

Interfaces are defined in Interface Definition Language (IDL)

An interface has an GUID as an indentifier

IUnknown

IDispatch


InterfacesInterfaces

Word processor version 1 Word processor version 1

Word processor version 2Word processor version 2

Dictionary version 2Dictionary version 2

ISpellCheck


ISpellCheck

Extend the existing interface for new functionality

An old word processor can not work with a new version of the dictionary.


More About InterfacesMore About Interfaces

Word processor version 1 Word processor version 1

Word processor version 2Word processor version 2


ISynonyms

ISpellCheck


ISpellCheck

A new interface for new functionality

All versions can work with all versions


Introduction to XMLIntroduction to XML

Magnus Larsson


XML OverviewXML Overview

XML = Extensible Markup Language

Defined by the WWW Consortium www.w3c.org

Structured representation of data

Industry standard, cross vendor/platform

Encode content, schema and semantics

Stateful object model

XML Elements = Classes

XML Element Attributes = Properties

http://www.w3c.org/


XML, SGML, HTMLXML, SGML, HTML

SGMLSGML

XML

HTMLHTML

Meta level


XML is validXML is valid

Valid XML = XML combined with a DTD or XML Schema

DTD = Document Type Definition

DTD defines the rules for the data

Which elements are present

What is the relationship between elements

An XML parser uses the DTD to verify that the XML is well formed


Example XML, What is the data?Example XML, What is the data?

Style Sheet or XSL, How is the data Style Sheet or XSL, How is the data

presented?presented?

<?xml:stylesheet type="text/xsl" href="testXML.xsl" ?>


XML and XSLXML and XSL


SOAPSOAP


COMObjectCOM

Object

CORBAClient

CORBAClient

COM/CORBAAdapter

COM/CORBAAdapter

How to make components interactHow to make components interact

There is a problem when components from different models wants to communicate

Adapters can be used


boolean PlaceOrder([in] Title string, [in] Author string, [out] DaysToDelivery integer);

Simple Object Access ProtocolSimple Object Access Protocol

SOAP defines the messages with XML

SOAP piggybacks its messages on HTTP

Defines a way to communicate between different component models

Works through fire-walls

COMObjectCOM

Object

CORBAClient

CORBAClient

POST /BookServer HTTP/1.1 Host: www.newbooks.com Content-Type: text/xml-SOAP Content-Length: 160 MessageType: Call <SerializedStream> <PlaceOrder> <Title>Sofies world</Title> <Author>Jostein Gaarder</Author> </PlaceOrder> </SerializedStream>

POST /BookServer HTTP/1.1 Host: www.newbooks.com Content-Type: text/xml-SOAP Content-Length: 160 MessageType: Call <SerializedStream> <PlaceOrder> <Title>Sofies world</Title> <Author>Jostein Gaarder</Author> </PlaceOrder> </SerializedStream>

SOAP Message Call


Simple Object Access ProtocolSimple Object Access Protocol

SOAP defines the messages with XML

SOAP piggybacks its messages on HTTP

Defines a way to communicate between different component models

Works through fire-walls

COMObjectCOM

Object

CORBAClient

CORBAClient

HTTP/1.1 200 OK Connection: close Content-Type: text/xml-SOAP Content-Length: 177 MessageType: CallResponse

<SerializedStream> <PlaceOrderResponse> <__return>1</__return> <DaysToDelivery>7</DaysToDelivery> </PlaceOrderResponse> </SerializedStream>

HTTP/1.1 200 OK Connection: close Content-Type: text/xml-SOAP Content-Length: 177 MessageType: CallResponse

<SerializedStream> <PlaceOrderResponse> <__return>1</__return> <DaysToDelivery>7</DaysToDelivery> </PlaceOrderResponse> </SerializedStream>

SOAP Respose


Overview of the .NET FrameworkOverview of the .NET Framework

[email protected]


What is .NET?What is .NET?

Publicly launched at PDC 2000

.NET is a platform that enables:Software as services, especially over the web

Distributed computing

Componentization

Enterprise services

.NET is a platform that enables:Software as services, especially over the web

Distributed computing

Componentization

Enterprise services


.NET Platform .NET Platform

Operating Systems

Common Language Runtime

Base Class Library

ADO.NET and XML

ASP.NET Windows Forms

Common Language Specification

VB C++ C# JScript …V

isual S

tud

io.N

ET


.NET Framework Components.NET Framework Components

Common Language Runtime (CLR)

Common type system for all languages

Runtime environment

Class libraries (.NET Framework)

Base class libraries, ADO.NET and XML

Windows Forms for, Win32 applications

Web application platform ASP.NET

Interactive pages

Web services that are SOAP enabled


MSIL

Compilation and ExecutionCompilation and Execution

Source Code

Source Code

Language CompilerLanguage Compiler

Compilation

Before installation or the first time each method is calledExecution

JIT Compiler

JIT Compiler

NativeCode

NativeCode


Multi-Language DevelopmentMulti-Language Development

Advanced multi-language features

Cross language inheritance, exceptions

Over 20 languages currently supported

VB, C++, C#, Java, JScript, Pearl, COBOL

High leveraged tools

Debuggers, etc work with all languages


IEC 61131-1IEC 61131-1


IEC 6 1131-3IEC 6 1131-3

Language for realtime controller components

Five languages

Ladder diagram

Structured text

Function block diagram

Instruction list

Sequential functional chart


IEC 6 1131-3IEC 6 1131-3


BlackboxBlackbox


BlackBox Component BuilderBlackBox Component Builder

Development Environment

Component Pascal

Editor, Compiler, Debugging Tools, Repository, etc.

Component Frameworks

Extensible library of Components

GUI Builder

Based on Compound Documents


Component PascalComponent Pascal

Compiled to native code

Modular

Unique combination of Objects and Modules

Type checking (static & dynamic)

Safe as e.g. Java

Garbage collector


Component PascalComponent Pascal

Can be used on all levels

Assembling components (scripting)

Developing componentsFrom application-level to system-level components

(garbage collector, component loader)

Specifying architectures and interfacesSpecial support to express architectural properties

page 1, june 1, 2015 cbse – graduate course an introduction to different component technologies...

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