Introduction
Our goal with this IBM Redbooks publication is to provide all of the information necessary for you to connect mobile devices to IBM Customer Information Control System Transaction Server (CICS TS). You can do this whether you want to maximize existing enterprise services already hosted on CICS, or to develop new services supporting new lines of business.
This book describes the steps necessary to develop, configure, and deploy a mobile application that connects either directly to CICS Transaction Server, or to CICS using IBM Worklight Server. In addition, we will show you how you can use CICS to operate as a requester of JavaScript Object Notation (JSON)-based services.
With this book, you will be able to understand the key architectural decisions associated with making CICS services available to mobile devices, and find example code to quickly get up and running. Our main scenarios are based on the general insurance application (GENAPP) Support Pack (CB12), which you can download and try for yourself, following the examples in this book. Download it from the following website:
The following topics are covered in this chapter:
1.1 Overview
For many years CICS Transaction Server has been capable of hosting mobile enterprise services. The introduction of web services capabilities in CICS Transaction Server V3 provided the fundamental building blocks of service connectivity, enabling the adoption of service-oriented architecture (SOA), and underpinning today’s mobile solutions.
CICS has continued to add new capabilities to the run time. From a mobile perspective, the introduction of the CICS TS Feature Pack for Mobile Extensions provides JSON and Representational State Transfer (REST)-conforming (RESTful) web service support, further enhancing the options for enterprise applications to mobile devices.
Customers around the world use CICS TS to host hundreds of millions, and in some cases billions, of transactions per day. As the number of mobile devices worldwide continues to grow, so does the variety and volume of workload that they drive. CICS has the capacity to scale up in support of this increasing mobile workload, providing an exceptional platform for hosting mobile workloads.
1.2 Business value
By extending existing enterprise applications onto a mobile platform, your business can capitalize on its existing investment without the need to develop an entirely new solution to support mobile services. In addition, a line of business can now offer service to users who increasingly expect to be able to interact with a company using their mobile phone.
As a platform, the primary benefits offered by CICS in support of mobile devices are noted in the following list:
•Provide reuse of existing enterprise services.
•Using the established web service technology within CICS, it is relatively simple to build a set of enterprise services that can be used by a mobile device.
•Provide simplified consumption of enterprise data using JSON-formatted data.
A common misconception is that enterprise data in CICS can be hard to use. The CICS TS Feature Pack for Mobile Extensions provides support for JSON data, which is rapidly becoming the standard format for data interchange on mobile devices.
•CICS already operates at the heart of the enterprise.
Hosting mobile applications within CICS brings them closer to the enterprise data that they are accessing, minimizing application path lengths and keeping response times down.
•Adopt a RESTful architectural style for service delivery.
A RESTful architectural style is one where the target resource, and the operation to be performed against it, are defined by a combination of a well-structured Uniform Resource Identifier (URI) and one of the four Hypertext Transfer Protocol (HTTP) methods (GET, POST, PUT, and DELETE).
•Provide capacity to manage mobile workload.
We noted earlier that customers around the world use CICS TS to host hundreds of millions, and in some cases billions, of transactions per day. CICS Workload Management provides a robust and scalable platform suitable for supporting the heaviest of mobile workloads.
1.3 Solution overview
This book introduces four different approaches to building mobile services in CICS TS. In two of these three cases, details are provided for how to connect the mobile application, either directly to CICS or via IBM Worklight Server. Chapter 6, “IBM Worklight configuration” on page 47 describes in more detail the architectural implications of connecting the mobile application, either directly or indirectly, via IBM Worklight Server.
The different approaches that we describe in detail are summarized in the following list:
•The top-down approach. Figure 1-1 shows the suggested method of building new enterprise services for a mobile application in CICS. This approach lends itself to the RESTful architectural style. This approach enables you to create a set of services with a concise interface. For more information about the RESTful architectural style, see the following website:
Figure 1-1 A possible way to implement a JSON web service starting from the JSON schema
•The bottom-up approach. Figure 1-2 on page 6 shows perhaps the fastest approach for delivering enterprise services to mobile devices. Building on an existing SOA, the bottom-up approach enables you to define a JSON or SOAP interface to an existing Common Business Oriented Language (COBOL), C/C++, PL/I, or Java application. This approach maximizes the reuse of existing assets, and minimizes the creation of new components.
Figure 1-2 shows the bottom-up approach.
Figure 1-2 Architecture for a JSON web service to be driven by high-level language data structure
•The requester mode approach. Figure 1-3 shows how this approach enables CICS to participate in JSON-based interactions, and to make requests against external service providers that offer a JSON-based interface. Though not strictly a pure mobile scenario, the capabilities offered by the CICS TS Feature Pack for Mobile Extensions provide CICS with additional options for connecting to the wider enterprise using JSON-formatted data.
Figure 1-3 LINKable CICS program transforms data between high-level data structures and JSON
•Java API for RESTful Web Services (JAX-RS) is a programming interface that provides support in creating web services according to the REST architectural pattern, as shown in
Figure 1-4. REST is an architecture style for designing networked applications without the need for complex mechanisms, such as Common Object Request Broker Architecture (CORBA) or SOAP.
Figure 1-4. REST is an architecture style for designing networked applications without the need for complex mechanisms, such as Common Object Request Broker Architecture (CORBA) or SOAP.
The pattern involves client/server communications where the state of an application is held by the client, which reduces processing required on the server. Using the IBM WebSphere Liberty profile provided in CICS TS V5.1, you are able to write your business applications using JAX-RS.
Figure 1-4 JAX-RS provides a rapid and easy development of RESTful-enabled Java applications
1.4 Solution architecture
The architecture for an enterprise mobile solution based on CICS will vary, depending on business requirements and the business data that the applications require. This book provides information about and demonstrates the following solution architectures:
•Direct to CICS
•A two-tier Worklight and CICS solution
The direct-to-CICS solution is one where the mobile devices communicate directly to CICS. In this architecture, other devices communicate with CICS through the existing web services provided by CICS. This scenario is ideal when the devices and networks involved are all trusted, the applications involved do not require frequent updates, and the applications do not run on multiple platforms.
An alternative solution is an architecture with one or more layers between CICS and the user devices. Worklight is a solution that provides governance and security for your mobile applications, along with a powerful software development kit (SDK) for rapid development of your enterprise applications on most major platforms.
In this architecture, the mobile devices communicate with the Worklight Server, which ensures that the device has access rights to make requests to CICS. If approved, this request is then sent to CICS, and the CICS application is run.
IBM Worklight also manages the versioning of applications, enabling new versions of the application to be created without the need for multiple versions of the back-end business applications, each with logic to handle the different requests. On the different platforms, features, such as notifications, are also handled and standardized by Worklight.
Figure 1-5 shows a typical architecture of how Worklight and CICS TS can be used in conjunction to extend the reach of your CICS applications to a mobile platform.
Figure 1-5 Mobile devices access services hosted on CICS TS using Worklight and CICS TS
1.5 Usage scenarios
The following scenarios show several ways in which CICS TS can be used to solve enterprise mobile business solutions:
•As an insurance company, you identify a requirement to enable your policy holders to view and make claims on their policies directly from their mobile device. To remain competitive, the mobile application needs to be available as soon as possible. To facilitate rapid development, and to make your services hosted on CICS available to the application, you choose the bottom-up approach.
Using your COBOL copybooks, you generate a JSON schema that enables the mobile application to communicate with CICS web services with a lightweight payload. CICS manages the transformation between JSON and the COBOL copybook structure, and your CICS services have been made available with ease.
•As a CICS Service provider, you have been informed of a business requirement to make your CICS applications available through a standardized RESTful pattern. By using the top-down approach, you externalize your existing and new CICS services through a RESTful architecture. This enables your services to be called through a unified approach understood throughout the business.
•As an airline carrier, you have a requirement to access data from your partner companies to accurately allocate seating through your on-demand ticket purchasing system. You are informed that your partner company only externalizes their services through a RESTful pattern, with JSON as the data format of choice.
You use the new CICS-provided LINKable program, along with the existing CICS WEB API, to communicate with the partner company. These tools enable you to communicate without the added cost of development, while maintaining a bespoke communication layer.
1.6 Integration of CICS and other IBM products or solutions
CICS enterprise mobile solutions can be deployed in a product stack with the following IBM products:
•Worklight is a hybrid mobile solution offering governance, and a powerful SDK to build applications with a server component that will drive the future mobile world.
•IBM DataPower enables you to secure, integrate, and optimize SOA capabilities that scale.
CICS enterprise mobile solutions also function with the following existing solutions that work with CICS:
•WebSphere MQ
•IBM DB2®
•IBM Integration Bus (formerly WebSphere Message Broker)
1.7 Supported platforms
CICS web service support is available from CICS TS V3 and later. For further details about CICS TS V3 requirements, see the following website:
CICS TS Feature Pack for Mobile Extensions V1.0 is available on CICS TS V4.2 and CICS TS V5.1. For further details of the requirements of CICS TS Feature Pack for Mobile Extensions V1.0, see the following website:
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