Scale Up Access to your 4GL Application using Web Services David Lund Sr. Training Program Manager, Progress

Scale Up Access to your 4GL Application using Web Services

David LundSr. Training Program Manager, Progress

© 2005 Progress Software Corporation2 Progress 4GL Web Services

Session Focus

Identification of the best places to use web services

Choosing web service standards and technologies

Sample implementation of Progress 4GL Web Service

Implementing Progress 4GL Web Services


Agenda

Getting started

Standards

Web service provider

Deployment

Web service consumer

Progress 4GL Web Services


How Does This Relate to SOA

Service Oriented Architecture (SOA)– logic concept behind the physical

implementations One type of physical implementation is

web services

Service Oriented

Communications Communications

Provider


The Value of Web Services

Connects applications together through agreed upon standards– Share information between applications

without writing a customized interface

– Application can be written in any language Provides an alternative method to access

existing applications – For example: Access business logic of a

client server application over the web


Common Business Logic

OpenEdge® AppServer™ = Center of the business logic universe

Ways to access business logic– .NET™ Open Client– 4GL Client– Java™ Open Client– Web services– WebClient™– WebSpeed®– OpenEdge Adapter for

SonicMQ®

The basics


Configuration

Client/Server

Client(Consumer)

Clients

OpenEdgeApplication

Server

Server(Provider)

WebService


Sorting out the Acronyms

Standards

SOAP WSDL XML SchemaStyle/Use

Provider

AppObj

ProcObj

SubAppObj

WSM

Deployment

HTTP/HTTPSJSEWeb ServerWSA Session Model WSAD

Consumer


Agenda

Getting started

Standards


Deployment




SOAP

Protocol for message exchange– Lightweight & XML-based

Independent– Encoding – Transport– Language– Platform

Extensible – Extra context via headers

Supports – message typing– strong typing– structured data

Standards

SOAP


WSDLWeb Service Description Language

This is the service contract– Data type mapping– SOAP message format– How to call the Web service

XML Document Created by

– Web service provider Used by

– Web service consumer

Standards

SOAP WSDL


XML Schema

Comprise of a set of agreed upon rules – Structure, Content,

Semantics A means for defining for

XML Documents– Used to define formats for

SOAP and WSDL messages Maps 4GL data types

SOAPWSDL XML Schema

Standards


OpenEdgeWSDL Style/Use

RPC/Encoded– Messages use remote

procedure call (RPC) model– Data format uses SOAP data

model Document/Literal

– Messages use XML Document model

Defined as complex types in Types section

– Data format conforms to standard XML schema

Standards

SOAPWSDL XML Schema Style/Use


Web Services is Defined by Standards

Web Services– A set of standards that comprise a platform for

building distributed, interoperable applications

Progress 4GL Web Services utilizes W3C standards– WSDL 1.1 (W3C Note – de facto standard)– SOAP 1.1 HTTP Binding– 2001 XML Schema


Agenda

Getting started

Standards


Deployment




Open Client Object ModelA

pp

Ob

ject

Pro

cO

bje

ctS

ub

-A

pp

Ob

j Always one Establishes connection External procedures

Zero or more Shares connection Internal procedures/UDFs

Zero or more Shares connection External procedures

Provider

AppObj

ProcObj

SubAppObj


WSMWeb Service Mapping File

Lists– Objects– Operations

Identifies Session Model

Initializes deployment information

Created by ProxyGen

Provider

AppObj

ProcObj

SubAppObj

WSM


ProxyGen Tool

4GL Business

Logic(r-code)

Web Services Mapping

file(.wsm)

Project file

(.xpxg)

Web Service Description

Language file(.wsdl)

AppObject

ProcObject

Sub-AppObj

Log file

(.log)


ProxyGen Tool

ProcObjPersistenData.r

AppObjFindEmpByNum.r

ListDeptEmp.r

Selecting procedures


ProxyGen ToolGeneral Tab

AppServiceAppService

Generation Options

GeneratedGeneratedProxyProxy


ProxyGen ToolWeb Services Tab

Session ModelGeneration Options

URL

Namespace

Style/Use


Demonstration

ProxyGen


Agenda

Getting started

Standards


Deployment




HTTP/HTTPS

Communications Protocol

Used to transport SOAP messages– SOAP 1.1 HTTP Binding

Post/Response

HTTPS– SSL– Securely send messages

Deployment

HTTP/HTTPS


JSEJava Servlet Engine

Runs servlets– Progress 4GL Web Services

deploys a servlet

JSE’s available from 3rd party vendors– Examples use Apache

Tomcat Has built in Web Server

– Not recommended for production

Third party components…Deployment

JSE

HTTP/HTTPS


Web Server

Required

Accepts HTTP/HTTPS communications

Hosts JSE

Third party components…Deployment

Web Server

HTTP/HTTPSJSE


WSAWeb Services Adapter

WSA = Java™ servlet

Runs in JSE

Administers and provides access to deployed Progress 4GL Web services

Decodes and encodes SOAP messages

Deployment

WSA

HTTP/HTTPSJSEWeb Server


WSA in JSEon Web Server

HTTP Listener

WSAJava Servlet W

eb S

erve

r

SOAP / HTTPConsumer


Session Model

Session Managed– State-aware, State-reset,

Stateless

– Holds resources

Session Free– Does not maintain any state

Deployment

Session Model

HTTP/HTTPSJSEWeb ServerWSA


WSADWeb Service Application Descriptor

Describes web service to the WSA

Information on how to access AppServer application

Deployment

WSAD

HTTP/HTTPSJSEWeb ServerWSA Session Model


Demonstration

Deployment

Progress E

xplorer


Agenda

Getting started

Standards


Deployment




Service Consumer

Calls the web service

Typical Scenarios– Application to Application

Business to Business Background

– End User Portions of application available

Consumer


The Client

POST SOAP over HTTP

ResponseSOAP over HTTP

Java™.NET

ProgressOther

Consumer

WSDL


Putting It All Together

HTTP Listener

WSAJava Servlet W

eb S

erve

r POST SOAP over HTTP

ResponseSOAP over HTTP

Client(Consumer)

OpenEdgeApplication

Server

Server(Provider)


Demonstration

Calling aWeb

Service

Server(Provider)

Client(Consumer)


In Summary

Identify where to use web services solutions

Choose the web service standards and technologies to suit your needs

Use the examples to help in implementing your own web service solutions

Implementing Progress 4GL Web Services


Documentation

OpenEdge Development– Web Services

– Progress 4GL Reference


Questions?Client/Server

WebService

Client

ClientsOpenEdgeApplication

Server

Server


Thank you for your time!
