© 2009 IBM Corporation
IBM Software Group
Mark Evans (evansm@us.ibm.com)
EGL Development
®

IBM Software Group | Rational software
 © Copyright IBM Corporation 2009. All rights reserved.
 The information contained in these materials is provided for informational purposes only, and is provided AS IS without warranty of any kind, express or implied. IBM shall not be responsible for any damages arising out of the use of, or otherwise related to, these materials. Nothing contained in these materials is intended to, nor shall have the effect of, creating any warranties or representations from IBM or its suppliers or licensors, or altering the terms and conditions of the applicable license agreement governing the use of IBM software. References in these materials to IBM products, programs, or services do not imply that they will be available in all countries in which IBM operates.
 This information is based on current IBM product plans and strategy, which are subject to change by IBM without notice. Product release dates and/or capabilities referenced in these materials may change at any time at IBM’s sole discretion based on market opportunities or other factors, and are not intended to be a commitment to future product or feature availability in any way.
 IBM, the IBM logo, the on-demand business logo, Rational, the Rational logo, and other
IBM Rational products and services are trademarks or registered trademarks of the
International Business Machines Corporation, in the United States, other countries or both. Other company, product, or service names may be trademarks or service marks of others.
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 Brief Introduction to Web Services
 RBD/EGL – A tool for Building Web Services
 Options for EGL Integration with COBOL Web Services
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 Web services provide standardized access to assets for different software applications residing on disparate platforms
 Web service definitions provide abstract interfaces which allow for loose coupling between business components – implementation can vary without affecting consumers
 You can reuse applications exposed as Web services in a variety of service-oriented architecture frameworks, such as a process choreographer or an enterprise service bus .
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 Basic Problem Statement:
 An Existing COBOL program on CICS contains the business/data logic for a business transaction
 A requestor/client outside CICS needs to obtain this information
 Solution
 Create Web Service to “front end” the called program
 Provides standard interface

Many tools work with and can access web services
Requester
Needs info
From CICS
Web Service
CICS TS 3.x or Later
Callable
COBOL
Program
DB2
Or
Files
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IBM Software Group | Rational software
Enterprise Modernization and Web Services – Getting Started
 What’s Required?
1.
2.
3.






Standard Definition of the Services interface
SOAP format to contain the messages going back and forth
WSDL (Web Services Definition Language) to define the message content
A Web service (SOAP message) processor such as one of the following:
WebSphere Application Server
CICS
Tomcat
Other application servers
Tools to help build the necessary interfaces and work with the runtimes
CICS TS 3.x or later
Requester
Needs info
From CICS
SOAP Message/WSDL
Web Service
CICS
Web
Service
Runtime
WebSphere
Web Service
Support
Callable
COBOL
Program
DB2
Or
Files
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IBM Software Group | Rational software
 Brief Introduction to Web Services
 RBD/EGL – A tool for Building Web Services
 Options for EGL Integration with COBOL Web Services
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EGL Services Support – High Level View
At development time…
 focus on the business logic
 implement SOA design elements: Services & Interfaces
 leverage existing COBOL or RPG developers for new SOA development
 ignore deployment targets/technology while coding/testing
 Use Deployment Descriptor file to describe Deployment considerations
Use existing non-EGL Web Service
Create EGL Interface and EGL Records automatically based on existing WSDL
EGL
RUI/JSF/TUI
EGL
Service
EGL
Records
W
S
D
L
Build & expose EGL Web Service
Non-EGL
User of
EGL Service
EGL
Records
EGL
Interface
W
S
D
L
Existing
Service
EGL applications invoke operations in EGL Interface and send Records as parameters
Deploy EGL Services…
 in Java to Java to WAS, Tomcat, Win, Linux, HP-UX,
Solaris, iSeries
 in COBOL to CICS, System i
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 A service is similar to a library, with the major exception that a service may be located remotely from its client.

The client
– which can be a program, JSF handler, library, or other service - uses (invokes) the functions defined in the service.
 Services have one or more public functions that contain business logic. Once you have written the business logic, you can deploy the service as one of the following:
 an EGL Java™ service
 a Web service
 an EGL COBOL service
 a CICS® Web Service
 In general, you create a Service part when you want to make your business logic available to other programs, either locally or remotely, in an encapsulated way.
Example of an EGL Service
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Concepts built into the language

 Provides abstract definition of Service
 Can be created directly from WSDL for use by Web Service clients
 Access external services as EGL services
Interface IStockQuoteService
Function getQuote(symbol String) returns ( money ); end
Service StockQuoteService implements IStockQuoteService
Function getQuote(symbol String) returns ( money )
… end end
SOA
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 EGL Deployment
Descriptor files are used to describe how EGL service applications are bound to the clients that call them, and vice versa
 Generates wrapper program for each service
 Service Client Bindings
 How to invoke the service
 Services Deployment
 How the service is invoked
 Sharable Protocols
 Common information for clients and services
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IBM Software Group | Rational software
 Brief Introduction to Web Services
 RBD/EGL – A tool for Building Web Services
 Options for EGL Integration with COBOL Web Services
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IBM Software Group | Rational software
RBD/EGL SOA Integration with Enterprise Programs – Options
EGL and non-EGL client
Web Service
Requester SOAP Message
WSDL
CICS TS 3.x or later
Channel
RDz
Generated
Handlers
Cobol Call
Callable
COBOL/EGL
Program
CICS
Web
Service
Runtime
Channel
EGL
COBOL
Web Service
Cobol Call
Wrapper
EGL
COBOL
Service
Service Invocation
WebSphere
EGL
Client
CICSECI or CICS J2C
Call Statement
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IBM Software Group | Rational software
RBD/EGL SOA Integration – Option 1
EGL Integration with RDz Generated WSDL/Handlers
CICS
Web
Service
Runtime
Channel
CICS TS 3.x or later
RDz
Generated
Handlers
Cobol Call
Callable
COBOL/EGL
Program
SOAP Message
Web Service
Requester
WSDL
EGL and non-EGL client

Use Rational Developer for zSeries tools to:
 Create WSDL and/or WSBIND needed by CICS Web Services Runtime
 Create COBOL “wrappers” to front end the COBOL program
 More on this later

Use EGL to:
 Create an EGL interface from the RDz generated WSDL
 Create a client binding (how to invoke the service) in the EGL deployment Descriptor
 Create a EGL Client (e.g. Service) to invoke this interface
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 Build, Deploy, and Test Web services from existing applications
 Create source code skeletons from web service definitions
 Map web service definitions to existing application modules
 Supports traditional languages
 COBOL
 PL/I
 Supports zOS specific runtimes
 CICS
 IMS
 Batch
*RDz = Rational Developer for system z
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Consuming EGL Web Services – Create Interface and Client bindings


Copy the WSDL from RDz into the EGL project
Select the WSDL file and choose:
1.
“ Create EGL Client Interface ”
2.
Choose which web service you want to interface with
( Next )
3.
Choose (filled in for you based on WSDL)
 Location of source
 Which functions to interface with
4.
Click “ Next
” to specify client bindings
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IBM Software Group | Rational software
Consuming non-EGL Web Services – Resulting Definitions



–
Need to fill in URI with URL used to invoke the web service http://<hostname>:<soaplistenerport>/<relativepathofservice>
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CICS TS 3.1
EGL COBOL
Program or
Service
(including
3270 pgms)
Cobol Call
COBOL
Web Service
Proxy
Channel
CICS
Web
Service
Runtime
SOAP Message
HFS
WSDL
WSBIND
Service
Provider
 Generated from the EGL deployment Descriptor (web service client bindings)
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RBD/EGL SOA Integration – Option 2
Using EGL Web Services to create new logic or wrapper existing programs
CICS TS 3.x or later
Callable
COBOL/EGL
Program
Web Service
Requester
SOAP Message
EGL and non-EGL client
WSDL
CICS
Web
Service
Runtime
Cobol Call
Channel
EGL
COBOL
Web Service
Wrapper
Cobol Call
EGL
COBOL
Service
 Use RBD/EGL to:
 Create a service part (see previous slides)

Service part calls native COBOL program
 Add EGL Service Binding information to the EGL Deployment Descriptor
 Generate EGL service and Deployment Descriptor which creates
 WSDL and WSBIND needed by CICS Web Service Runtime
 COBOL modules to implement the EGL COBOL web service
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Deployment
Descriptor file
(.egldd file)
HFS
WSBIND
WSDL
Build Descriptor file
(.eglbld file)
EGL Build
Server
CICS
Generation
Services Source
(.egl files) z/OS
PDS w/Load
Modules
 Deployment Descriptor File  WSBIND, WSDL, & Wrapper COBOL programs
 Services  COBOL program
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 For resulting load modules :
 In CICS DFHRPL;


Add PDS with load modules for service and service wrapper
Add EGL COBOL Runtime library
 In CICS CSD


Add CICS Program entries (unless dynamically created)
Add any required DB2 related entries if program accesses DB2
 Install CICS groups/entries as necessary
 Perform CICS NEWCOPY if replacing existing load modules
 For Web Services Infrastructure :
 Add CICS Pipeline Entry to specify target HFS directories that generation writes to
( one time if you want to always generate to same HFS directory)
 Perform a CEMT P PIPELINE SCAN to:



Enable the Pipeline
Create WebService entry based on information in generated WSBIND file
Create URIMAP entry based on information in generated WSBIND file
NOTE: CICS Userid must have permission to write to HFS directories specified in Pipeline definition
 If using Transaction other than CPIH in Web Service Entry



Recommended if using EGL generated Web Service
Still must be associated with same program example as CPIH
Can be done by CEDA COPY command:
–
CEDA COPY TRANSACTION(CPIH) GROUP(DFHPIPE) AS(<newname>) TO(<group>)
 Install CICS group/entries as necessary
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IBM Software Group | Rational software
RBD/EGL SOA Integration – Option 3
EGL Services and Call Interface
EGL and non-EGL client
Web Service
Requester SOAP Message
WSDL
CICS TS 3.x or later
CICS
Web
Service
Runtime
Cobol Call
Channel
EGL
COBOL
Web Service
Cobol Call
Wrapper
EGL
COBOL
Service
Callable
COBOL/EGL
Program
Service Invocation
WebSphere
EGL
Client
CICSECI or CICS J2C
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EGL
 EGL also has the concept of an EGL service
 Which is:
 Accessing the generated service directly using
– CICS ECI (remote invocation)
– CICS JCA/J2C (remote invocation)
– COBOL Calls
 From EGL Web Service Client
– EGL generated Java under WAS (libraries/services/jsfHandlers)
– EGL generated Java running outside WAS
– EGL generated COBOL running as 3270/CICS Batch programs in CICS
 With remote invocation (CICS ECI or CICS J2C)
 No XML parsing
 No WSDL processing
 Can utilize Channels and Containers
 Data can be dynamic length (dynamic arrays, in and out types, etc)
 EGL handles the data conversion
 Should be better performance (less parsing)
 Can use same generated EGL Service code as used through Web Services
 i.e. no re-generation required
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IBM Software Group | Rational software
EGL Services vs Web Services – Controlled via Web Client Bindings
 You can create multiple Web
Client Bindings
 Allows you to create multiple ways for the services to be invoked and
 Allows service client to determine which protocol to use by
 Referencing name in the service/interface declaration using “ bindingKey ”
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
Standard EGL Call statement identifies the program
 Call “myprog” (parm1, parm2,…);
 Parameters:
 Can be items and/or records (up to 30)
 Passed as values across network
 Converted to pointers on mainframe as needed
 Data converted on Client side before sending to mainframe
 All are treated as in/out parameters (sent both ways)
 CICS and IMS…total records can only be 32K unless channel/containers used
 Data received using normal “linkage” methods for target program

EGL communications layer

Provides the interface to various target specific communication protocols

Developer does not need to know anything about:
 APIs to make the remote call
 How the call is physically implemented
 Anything about conversions
The details of making the connection to the remote system are specified in an
EGL “build file” through a linkage options part
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 Shows existing called programs in name space.
 Resulting code
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IBM Software Group | Rational software
RBD/EGL SOA Integration with COBOL – Call Interfaces
Client
AIX/Linux/zOS
WAS web
Services
CTG Server
WAS server
TCP/IP
MRO/EXCI
EGL Generated
Web Service code
Call Programx
J2C Config
EGL
Generated
ProgramX
Or
Native
COBOL
Programx
CICS
CTG Server
 Web Service is created using EGL wizard based on already created EGL Programx
 No additional coding needed by programmers…just develop called program and generate needed artifact
 CTG Server can reside on distributed or z/OS system… not needed on both .
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IBM Software Group | Rational software
EGL Build File
1
1.
Build Descriptor must associate the linkage options to use (this does not happen by default!)
So can be different ones for debugging vs deployment if you have different build descriptors
Program callLink applies to
Type of callLink
Properties vary by type
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IBM Software Group | Rational software
WebSphere Application Server
1
2
LAB5SER
Called
Program)
CICS
3
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Description
Required
Development Tool
Infrastructure
Other Factors
Option 1
Create WSDL using RDz and use EGL to invoke this WSDL (service)
Option 2
Use EGL to create CICS
Based web Services
Option 3:
Use Application Server for Web Service and call
COBOL pgm
Rational Developer for zSeries with EGL
CICS Web Service
 Does not require a separate application server
 Allows use of “native”
COBOL tooling (RDz) to build required artifacts
 Separate client technology tool needed
Rational Business
Developer
CICS Web Service
 Does not require a separate application server
 Allows development of client, service, and interaction with native program in single tool
(RBD)
 Defined EGL records can be used.
Rational Business
Developer
WAS (application server)
CICS Transaction
Gateway
 Allows use of existing application server if already in place
 Supports both binary
(CICSJ2C) AND SOAP based web service from same generated artifacts
 EGL Records can be used or created from
COBOL copybooks
(native COBOL)
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IBM Software Group | Rational software
 Services can represent a grouping of business logic:
 Each function in service is a piece of logic related to the group

E.g. AccountService
– GetAccount
–
UpdateAccount
– DeleteAccount
– Etc.
 One function can combine multiple business functions
 More on this in following slides
 Make sure you use exception handling for calls to host programs
 Use UI records (type basicRecords) on calls from RUI Handlers to service functions. Use different records (if needed) to call back to host programs.
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IBM Software Group | Rational software

Example: Change Amortize to call a program (on CICS) instead of calculating within it.
 Uses 1 record to pass data between RUI handler and service (inputData) (flexible)
 Uses different record to pass data between reused called program and service (usually fixed if from
VAGen
 Can be different depending on needs
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IBM Software Group | Rational software
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IBM Software Group | Rational software
 Reuse of existing CICS assets is possible
 Several ways to interact/reuse these assets
 Combination of RDz and RBD give:
 Great Flexibility in how the assets are invoked
 Ability to work within existing architectures/infrastructures
 The tools traditional programmers can use to build web services for the enterprise
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IBM Software Group | Rational software
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IBM Software Group | Rational software
Service
Requester
SOAP message
HFS pipeline config
WSDL
WSBind
CSOL
TCPIPSERVICE
CWXN
URIMAP matching
URIMAP dynamic install
PIPELINE dynamic install
WEBSERVICE
Generated by EGL
CICS TS V3.1
CPIH/User Defined Xact
Pipeline data mapping
Wrapper Pgm
Service Pgm
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IBM Software Group | Rational software

 For Port to listen on for SOAP requests

 To define the location of the
 WSDL
 WSBIND file (defines mapping of XML to data structure)

 This does the following
 Locates the WSBind file
 From the WSBind file, CICS will dynamically create a WEBSERVICE resource
 CICS will also dynamically create a URIMAP definition
–
URIMAP
– URL to WebService mapping

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IBM Software Group | Rational software

 Supplied by CICS


 WSBIND
 WSDL
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IBM Software Group | Rational software

Created by CICS from Pipeline Definition
 URIMAP name
 Generated by CICS
 Relative Path in URL
 Transaction to Start
 Pipeline to use
 Service Name
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IBM Software Group | Rational software
 Created by CICS from Pipeline Definition





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