Creating Web Services from RPG Applications

IBM Software Group

Creating Web Services from RPG Applications

Al Grega

IBM Rational Software

®

© 2008 IBM Corporation

IBM Software Group | Rational Software

What We’ll Cover …

 Web Services Overview

 Technical Overview

 Development and Deployment

 IBM i Web Services Server

 Rational Web Services Wizard

 Host Access Transformation Services

 Summary

© 2008 IBM Corporation 2


IBM i Developers Road Atlas for SOA

Model

Create

•RPG Modules

•HTML Forms

•Java beans

RPG

COBOL

C/C++

Assemble

4GL

PHP

•Business

Processes/

Services

Deploy

•Services

Available

Consumer Provider

Tools

Monitor

•Application

Created



How Did We Get Here?

 Evolution of the Web

 Document-centric =>



Application-centric =>

– Service-centric

Static Web Applications

Dynamic Web Applications

Web Services Portlet Applications



Web Service Definition

(from the Wikipedia.com)

“ A ' Web service' (also Web Service ) is defined by the W3C as "a software system designed to support interoperable machine-to-machine interaction over a network " [1] . Web services are frequently just Web

APIs that can be accessed over a network, such as the Internet , and executed on a remote system hosting the requested services.

”



What Are They?

 Web services

 Applications that are invoked over the Web

 An implementation of Service Oriented Architecture (SOA)

 Contain only business logic, do not have a user interface

 Self-contained

 Self-describing

Other Applications

Web Application

Internet


Web Service

6


Requirements Addressed By Web Services

 Interoperability – need a common communication protocol

 Between systems

 Between languages

 Interface Description Language

 Describe the service’s interface

 Clear and unambiguous

 Platform independent

 Retrieval of Service

 Search and retrieve available services

 Conventient integration at design time and runtime

 Security

 Protection of services

 Protection of data sent to/from services



Types of Web Services

 Business Information: access to a database or rapidly changing contents

 Stock quotes

 Currency conversion rates

 Address book

 Geographical data

 Business Integration: implementing a function or outsourcing a business process

 Reservations system

 Credit check

 Payment system

 Loan service

 Product catalog



Web Service Participants

 Provider: implements a Web service

 Requestor: has a business need

 Broker: lists all available services

2 find

Requestor

Broker

1 publish

3 bind/invoke

Provider










 Summary



Web Services Technology Stack

Discovery UDDI, WSIL

Description WSDL

XML Messaging SOAP

Transport HTTP, JMS, FTP, SMTP



Web services : Transport Layer

 HTTP

 Simple, stable, widely deployed

 Travels through firewalls

 Currently the most popular option for SOAP transport

 HTTP is synchronous

 If asynchronous transactions are required, consider using

JMS

 Other choices: FTP, SMTP

Broker

SOAP over

HTTP

SOAP over

HTTP

SOAP over

HTTP

Requestor Provider



Web services : Description Layer

1.

WSDL: Web Services Definition Language

 XML schema (vocabulary) describing a Web service interface

 Methods

 Parameters

 How to invoke the service

2.

Client applications use WSDL to generate Web service client proxy

Broker

3.

Web service client proxy contains code that invokes a Web service

2

Look up

WSDL

1

Publish

WSDL

Requestor Provider

3

Use WSDL to bind/invoke



Web services : XML Messaging Layer

 SOAP is a flavor of XML

 SOAP message contains a Remote Procedure Call (RPC) or any XML document

1 2 3

Web service

Client

Internet SOAP

Server

Web service

6 5 4

1.

The Web service client creates and sends a SOAP message

2.

The SOAP server listens for SOAP messages. SOAP server is an application running in an Application Server (for example, WebSphere Application Server)

3.

The SOAP server processes the SOAP messages and passes the request to a

Web service

4.

The Web service runs the specified method and returns the result to the SOAP server

5.

The SOAP server forwards the result back to the Web service client

6.

The Web service client parses SOAP response.



Web services : Discovery

 UDDI: Universal Description, Discovery and

Integration

 Registry of Web Services (the White, Yellow and Green pages)

 Information categorized by company and by service type

 Can be private or public

 Several public UDDI registries exist

 UDDI Server

 Ships with IBM i

 Included with WAS Express 6.0 and above

 WebSphere Service Registry and Repository

 Promotes reuse and eliminates redundancies

 Enable SOA governance of your services

 Optimizes the use of services in SOA by exchanging rich service information

© 2008 IBM Corporation www.strikeiron.com

www.xmethods.com

15









 Summary



What are your Options on IBM i?

 IBM i Web Services Server

 Bundled with the IBM i Operating System

 Creates web services from ILE *SRVPGM’s or *PGM’s

 Rational Web Services Wizard

 Bundled with Rational Developer for System i for SOA Construction

(RDI SOA)

 Creates web services from RPG and COBOL ILE source code

 Host Access Transformation Services

 HATS Toolkit available as a free download and is bundled with RDi

SOA

 Creates web services from any 5250 screen



Which method do you implement?

Where do you get the tool

Source *SRVPGM and *PGM ILE

Batch Modules

How it’s deployed IBM Integrated Web

Application Server for i (part of the O/S)

Where it’s deployed On the same IBM i system as the source ILE programs

Web Service

Standards

Tied to IBM i Operating System

(fewer updates)

Scalability

Web Services Server

Part of the IBM i Operating

System

Vertical

Tied to IBM i Hardware

Rational

Web Services Wizard

Bundled with RDi SOA* and other Rational IDE’s

RPG and COBOL ILE Batch

Source Code

WebSphere Application

Server Express (bundled with the IBM i O/S)

Anywhere that WAS runs

Tied to WebSphere

Application Server (frequent updates)

Horizontal

Can be clustered with WAS

Network Deployment

Host Access

Transformation

Services

Free Download and

Bundled with RDi SOA* and

HATS for 5250**

Any 5250 screen (no code required)

WebSphere Application

Server Express (bundled with the IBM i O/S

Anywhere that WAS runs

Tied to WebSphere

Application Server (frequent updates)

Horizontal

Can be clustered with WAS

Network Deployment

* RDi SOA is a separate chargeable product. Customers with WDSC AE licenses under maintenance may have entitlements to RDi SOA.

** HATS 5250 is a chargeable runtime product for deploying HATS projects and can be purchased via Passport Advantage. The free download HATS toolkit provides two connections for testing purposes.










 Summary



IBM Web Services Server Introduction

 IBM i Integrated Web service enhancements make it easy to get started with SOA on IBM i

 OS functional enhancement



Included in IBM i 6.1 (a.k.a. i5/OS V6R1)

 PTF’s for i5/OS V5R4 (get SF99114)

 Designed for ILE programmers

 Makes Web services easier

 Two parts

 The ‘Web Services server’, or service provider

 The ‘Web Services client’, or service requestor



IBM i Web service enablement goals

 Provide the SOA ‘Web Services’ runtime for

 Service provider

 Service consumer

 Provide options that do not require new skills / tools to ILE programmers

 Provide a Web service development environment independent of Rational development tools for IBM i (RDi

SOA)

 Provide a Web service deployment environment independent of WebSphere Application Server



Service provider program requirements

 Programs or service programs must be directly callable

 Distinct input & output parameters

 No requirements for user interface or interactive 5250 session

 Program call markup language (PCML) document defining the object location, parameters, entry points, etc.

 Created by CRTRPGMOD, CRTBNDRPG, CRTCBLMOD,

CRTBNDCBL commands

 Options PGMINFO (*YES), INFOSTMF (IFS location)

 5250 or WDSC RSE interface

 Can also embed PCML data within the program object, for instance

 CRTRPGMOD PGMINFO(*PCML *MODULE) {V6R1}

 H PGMINFO(*PCML:*MODULE) {V5R4}

 PROCESS OPTIONS PGMINFO(PCML MODULE)



Use Web Administration for i5/OS

http://hostname:2001/ or go directly http://hostname:2001/HTTPAdmin



Create the application server

Click on the Create New Web Services Server link

The Web Services

Server is part of the

IBM i Operating

System



Select the Install a new Web service option



Specify the program for the service interface


Identify the ILE batch module (*SRVPGM or PGM) that you want to create a web service from

26


Specify the Web service name


Give your service name. Remember this is the name that will be used by service requestors.

27


What ILE procedure's should be externalized as a Web service?

Choose the ILE procedures to use and identify what you want to be input or output parameters

(or both).



Specify the user profile for the Web service

Define what user

(authority & access) will be identified with this web service.



Configure library list for the Web service

Make sure to specify the libraries with all the objects that your web service will need to access.



Review the application server, service configurations, and Web service operations

Double check your work and click Finish.

The Web Service will be created automatically and a web service server instance will be started.



Managing and testing the IBM i Web service

You can test your web service with the web delivered web services test client.



Testing the Web Service

View your WDSL

Web Service Output and XML










 Summary



Web Service Wizard in RDi SOA

 Web Services wizard in RDi SOA generates a Web Services wrapper for a program or service program procedure

 Program or procedure must be able to run as batch

 Generated Web Service wrapper is deployed onto WebSphere Application

Server or the Integrated Web Application Server for IBM i Operating System

 Does not have to be deployed onto the same server as the program or service program

Example program to be called

Start the wizard by right-clicking on member in the RSE and selecting Web

Services > Create Web

Service



Web Service Wizard

 Select the blue hyperlinks to change the Web Application

Server, Web service runtime,

J2EE version, or Web project



The Service project and

Service EAR projects are the location where wizard generates files related to the

Web Service

 If a Service project or EAR project does not exist, it will be created for you!



Configuring the Web Service- Edit Program/Parameters

-File name shows the Program source file the wizard was launched from (ILE

RPG, COBOL, and PCML are valid)

-Browse files to select a different file

-The default Runtime configuration is taken from the i5/OS RSE connection

- Click Browse to choose an existing configuration (.config file)

 Selecting the Program (CUSTINFO), you can change the library, program type and program name

 Make sure you check the program type: *PGM or *SRVPGM!

 Expand the program to see program parameters

 Selecting a parameter to change its usage (input, output, both), data type, length, and CCSID



Editing the Runtime Configuration

Default sign-on information is taken from the i5/OS RSE connection

Alternatively, can specify use of program call Java Connection

Architecture connector for sign-on and connection management.

 Additional libraries can be specified that are added to the library list at runtime

 Library list from the job description is still used

 Additionally a current library and initial command can be set.

 They add additional time to each call to setup the environment, Use job description settings instead, where possible



Testing the Web Service: Web Services Explorer

 After the Web Service is generated you can:

 Test the Web Service

 Deploy the Web Service

 Generate a client

1. Select

WSDL operation

2. Enter a Customer ID

3. Go!



Testing the Web Service: Web Services Explorer

 Tips on Handling data structure arrays

 Many RPG Web Services need to return data structure arrays

– Return all parts within specified price range

 However, RPG does not have varying dimensional arrays

–

–

You have to prototype the maximum expected

But you don’t want to return empty elements from the

Web service

 Add parameter to prototype

–

–

Input value is number of elements in array

Output value is number of elements returned

 Use Program Call Bean + Web services wizard to generate code

 Paper to be published shortly

4. Results are shown in Status Pane

5. Click on Source to view the SOAP request and response messages










 Summary



HATS Web Service creation overview

 Create a HATS project



Setup Development environment

 Define host connections

 Create Macros



Navigate host screens

 Define input parameters & output data



Connect, data, disconnect macros

Optionally Set up session pooling



HATS Web Service Creation Overview - Continued

 Create an Integration Object

 Defines the programming interface to the macro



Create Web Service

 Web Service files



Web Service Definition Language (WSDL) file

 Test the Web Service with the Web

Services Explorer



Create a new HATS Project

Create a new

HATS

Project

Give the project a name

A HATS Project must be created even though you will not be transforming

5250 screens.

Click Next



Create a HATS macro to capture input and output data

Click

To Start

Macro

Name the

Macro

HATS includes a Host Terminal that allows you to see before and after shots of screen transformations. It also includes a Macro recording tool.

A macro is a script that drives through and interacts with the green screen applications.

•Developer define “screens” within the macros by identifying screen recognition criteria and actions to perform when the screen is reached.

•Developer links screens together to define the flow of the macro.


Click Finish to

Start recording

45


Extract Actions allow you to define output parameters

2nd: Press

Add Extract

Action button

1 st : Rope off

Customer

Name Info

Prompt and

Extract Actions allow you to grab

5250 screen data and use them as input and output parameters for your web services later.

Last

Click

Finish

3rd: Give the extract action a name screen



Change the Flow with Visual Macro Editor

The new Visual Macro Editor (VME) simplifies macro creation, debug and execution activities:

 Allows for easier handling of alternate / error flows.

 Helps decrease the number of logic and flow problems (since the flow can be clearly analyzed by both developers, expert users, and business analysts).



Create an Integration Object

An Integration Object (IO) is a

Java class that encapsulates a macro.

 Integration Objects can be called directly from Java

Server Faces (JSF), Struts, or standard JSP Web pages.

 Integration Objects can also be used in Enterprise Java

Beans (EJBs) or Web

Services .



Create the Web Service and WSDL File

HATS uses the same web services wizard as RDi SOA in out last example. This provides a consistent interface for creating web services for Interactive or batch RPG applications.


Last

Click

Finish

49


Test the web service

The Web Service Explorer is the same as RDi SOA too.


Click Go to call the web service

Double-Click

Status Line to see the results from the web service

50









 Summary



Consuming Web Services from RPG

 Overview







Based on Apache AXIS C++ Version 1.5+

Consists

 Tools

– Convert service’s WSDL to C/C++ APIs

 SOAP client

–

ILE Service Program

 Supported today

 Packaged with 5733-XT1

– V5R1, V5R2, V5R3, V5R4

 V6R1

– i5/OS SS1 Option 3

Supports

 C, C++, RPG, COBOL

 Web Services Description Language (WSDL) - document literal only

 Web Services Invocation (WSI) 1.1 basic profile compliance

StockQuote.wsdl

<wsdl:message name=" getQuoteRequest ">

<wsdl:part element=" impl:getQuote" name="parameters "/>

</wsdl:message>

<wsdl:message name=" getQuoteResponse ">

<wsdl:part element=" impl:getQuoteResponse " name="parameters"/>

</wsdl:message>

<wsdl:portType name="StockQuote">

<wsdl:operation name="getQuote">

<wsdl:input message="impl:getQuoteRequest" name="getQuoteRequest"/>

<wsdl:output message="impl:getQuoteResponse" name="getQuoteResponse"/>

</wsdl:operation>

</wsdl:portType>

Sample client

– requester code view

 Secure Sockets Layer (SSL)



Web Services Client for ILE

Developer generates stubs using Qshell script:

/QIBM/Proddata/OS/WebServices/V1/client/bin/wsdl2ws.sh

GetQuote.wsdl -lc –ogetQuote.Stubs

WSDL

WSDL passed into tool that generates

C/C++ stubs

1.

Stub Generation – Creating a Web Services Proxy

(“intermediary” for ILE RPG, COBOL )

2.

Compile and Bind

3.

Run the application

Generated StockQuote.h (C stub header file) extern void* get_StockQuote_stub(const char* pchEndPointUri);

C/C++ stubs extern void destroy_StockQuote_stub(void* p); extern int get_StockQuote_Status(void* pStub); extern xsdc__float getQuote(void* pStub, xsdc__string Value0);


Your RPG program calls this

C/C++ Stub passing parameters which in turn gets passed to the web service via the AXIS C++

Client

53


Consuming Web Services from EGL

 Pre-requisites

 An EGL project or EGL Web project

 An EGL deployment descriptor

 A Web Services Description Language (WSDL) file that describes the service you want to use, located somewhere in your workspace

 Steps

 Import or copy the service WSDL to your EGL project

 Add the WebSphere 6.x ServerType Option to the Build File

 Generate the services descriptor file

 In the client process - code a variable based on the

<serviceName> type

 Add a Bindservice property with the appropriate bindkey

 Code the call to the ServiceVar.function

– passing parameters

 More Information at the EGL Cafe

 http://ibm.com/rational/eglcafe



Enterprise Modernization Sandbox

Easy and fun way to quickly try practical scenarios guided by self-paced exercises

System z Sandbox

Launched 2/26

Examples and best practices provide low-risk, practical, hands-on path to understanding. Includes:

 Rational Developer for System z

 Rational Business Developer

System i Sandbox

Launched May 2008

Examples and best practices provide low-risk, practical, hands-on path to understanding. Includes:

 Rational Application Developer

 Rational Developer for System i

 Rational Transformation Workbench

 Host Access Transformation Services

 Rational Business Developer

 Rational Host Access Transformation Services

 Databorough xAnalysis

Full version software trials

‘Try online’ hosted environments

Tutorials

Online Resources

Full version software trials

‘Try online’ hosted environments

Tutorials

Online Resources http://www.ibm.com/developerworks/downloads/emsandbox/



7 Key Points to Take Home

1.

Web services are applications that are invoked over the Web

2.

Web services do not have a user interface and return information in form of XML

3.

Web services are the lowest common denominator in heterogeneous application to application connectivity

4.

When building Web services, focus on designing an interface for maximum interoperability and implementing business logic

5.

Use Rational and WebSphere Tools to generate and test Web services

6.

IBM i has everything you need to deploy web services from RPG applications

 Internal IBM Integrated Web Application Server for i and WAS Express

7.

RDi SOA provides the tools you need to build web services from

RPG Applications

 Remote System Explorer, HATS toolkit and the Web Services Wizard



Resources

 Demonstrations

 http://rational.dfw.ibm.com/whidemo/

 Integrated Web Services for i5/OS

 http://www.ibm.com/systems/i/software/iws/

 Web Services Wizard

 http://www.ibm.com/developerworks/edu/ws-dw-ws-wsat1.html

 HATS Web Services

 http://www.ibm.com/developerworks/websphere/library/techarticles/

0504_hardison/0504_hardison.html

 EGL Cafe

 http://ibm.com/rational/eglcafe

 IBM Technical Information and Examples

 http://www.ibm.com/developerworks/



Your Turn!

How to contact me:

Al Grega algrega@us.ibm.com



Trademarks and Disclaimers

8 IBM Corporation 1994-2008. All rights reserved.

References in this document to IBM products or services do not imply that IBM intends to make them available in every country.

Trademarks of International Business Machines Corporation in the United States, other countries, or both can be found on the World Wide Web at http://www.ibm.com/legal/copytrade.shtml

.

Intel, Intel logo, Intel Inside, Intel Inside logo, Intel Centrino, Intel Centrino logo, Celeron, Intel Xeon, Intel SpeedStep, Itanium, and Pentium are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries.

Linux is a registered trademark of Linus Torvalds in the United States, other countries, or both.

Microsoft, Windows, Windows NT, and the Windows logo are trademarks of Microsoft Corporation in the United States, other countries, or both.

IT Infrastructure Library is a registered trademark of the Central Computer and Telecommunications Agency which is now part of the Office of Government Commerce.

ITIL is a registered trademark, and a registered community trademark of the Office of Government Commerce, and is registered in the U.S. Patent and Trademark Office.

UNIX is a registered trademark of The Open Group in the United States and other countries.

Java and all Java-based trademarks are trademarks of Sun Microsystems, Inc. in the United States, other countries, or both.

Other company, product, or service names may be trademarks or service marks of others.

Information is provided "AS IS" without warranty of any kind.

The customer examples described are presented as illustrations of how those customers have used IBM products and the results they may have achieved. Actual environmental costs and performance characteristics may vary by customer.

Information concerning non-IBM products was obtained from a supplier of these products, published announcement material, or other publicly available sources and does not constitute an endorsement of such products by IBM. Sources for non-IBM list prices and performance numbers are taken from publicly available information, including vendor announcements and vendor worldwide homepages. IBM has not tested these products and cannot confirm the accu racy of performance, capability, or any other claims related to non-IBM products. Questions on the capability of non-IBM products should be addressed to the supplier of those products.

All statements regarding IBM future direction and intent are subject to change or withdrawal without notice, and represent goals and objectives only.

Some information addresses anticipated future capabilities. Such information is not intended as a definitive statement of a commitment to specific levels of performance, function or delivery schedules with respect to any future products. Such commitments are only made in IBM product announcements. The information is presented here to communicate IBM's current investment and development activities as a good faith effort to help with our customers' future planning.

Performance is based on measurements and projections using standard IBM benchmarks in a controlled environment. The actual throughput or performance that any user will experience will vary depending upon considerations such as the amount of multiprogramming in the user's job stream, the I/O configuration, the storage configuration, and the workload processed. Therefore, no assurance can be given that an individual user will achieve throughput or performance improvements equivalent to the ratios stated here.

Prices are suggested U.S. list prices and are subject to change without notice. Starting price may not include a hard drive, operating system or other features. Contact your IBM representative or Business Partner for the most current pricing in your geography.

Photographs shown may be engineering prototypes. Changes may be incorporated in production models.


Creating Web Services from RPG Applications

Creating Web Services from RPG Applications

What We’ll Cover …

IBM i Developers Road Atlas for SOA

How Did We Get Here?

Web Service Definition

(from the Wikipedia.com)

“ A ' Web service' (also Web Service ) is defined by the W3C as "a software system designed to support interoperable machine-to-machine interaction over a network " [1] . Web services are frequently just Web

APIs that can be accessed over a network, such as the Internet , and executed on a remote system hosting the requested services.

”

What Are They?

Requirements Addressed By Web Services

Types of Web Services

Web Service Participants

What We’ll Cover …

Web Services Technology Stack

Web services : Transport Layer

Web services : Description Layer

Web services : XML Messaging Layer

Web services : Discovery

What We’ll Cover …

What are your Options on IBM i?

Which method do you implement?

What We’ll Cover …

IBM Web Services Server Introduction

IBM i Web service enablement goals

Service provider program requirements

Use Web Administration for i5/OS

Create the application server

Select the Install a new Web service option

Specify the program for the service interface

Specify the Web service name

Specify the user profile for the Web service

Configure library list for the Web service

Review the application server, service configurations, and Web service operations

Managing and testing the IBM i Web service

Testing the Web Service

What We’ll Cover …

Web Service Wizard in RDi SOA

Web Service Wizard

Configuring the Web Service- Edit Program/Parameters

Editing the Runtime Configuration

Testing the Web Service: Web Services Explorer

Testing the Web Service: Web Services Explorer

What We’ll Cover …

HATS Web Service creation overview

HATS Web Service Creation Overview - Continued

Create a new HATS Project

Create a HATS macro to capture input and output data

Extract Actions allow you to define output parameters

Change the Flow with Visual Macro Editor

Create an Integration Object

Create the Web Service and WSDL File

Test the web service

What We’ll Cover …

Consuming Web Services from RPG

Web Services Client for ILE

Consuming Web Services from EGL

Enterprise Modernization Sandbox

7 Key Points to Take Home

Resources

Your Turn!

How to contact me:

Al Grega algrega@us.ibm.com

Trademarks and Disclaimers

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