CICS® can
interface with the Web as a server, receiving requests from Web clients; or
as a client, making requests to a server.
Web client requests serviced by CICS applications
- Using CICS Web
support
- CICS Web
support enables a CICS region to act as an HTTP server.
- CICS Web
support can provide static responses to Web clients, using CICS documents
or static files.
- Web-aware user application programs can receive and analyze HTTP requests,
and provide dynamic application-generated responses.
- CICS Web
support includes a range of CICS services supporting Web client access to non-Web-aware
applications. Web clients can make requests to access CICS programs which are designed to communicate
with virtual 3270 terminals, and CICS programs which are designed to be
linked to from another CICS application using COMMAREAs or channels.
- CICS Web
support also supports non-HTTP requests from clients.
CICS Web
support is described in CICS Web support concepts and structure.
- Using Web services
- A Web service is a software system designed to support interoperable machine-to-machine
interaction over a network. It has an interface which is described in a machine-processable
format (specifically, Web Services Definition Language - or WSDL). CICS Transaction
Server Version 3 can be a requester or a provider of Web services. Web services
are described in the CICS Web
Services Guide.
- Using IBM® HTTP
Server
- IBM HTTP
Server provides access to CICS applications through the External CICS Interface
(EXCI) and the CICS business
logic interface. For more information, see The CICS WebServer plugin and Introduction to the CICS business logic interface.
- Using CICS Transaction
Gateway
- The CICS Transaction
Gateway provides a set of Web server facilities for access to CICS applications
by a Web client. These include Java™ classes and Java beans for writing application-specific
server programs (servlets) and browser programs (applets), as well as IBM-supplied
code for common functions. There are classes for access to both traditional
and object-oriented CICS applications. Applets and servlets use CICS-supplied
classes to construct ECI (External Call Interface) and EPI (External Presentation
Interface) requests. (Note that CICS Transaction Gateway for z/OS® supports
ECI but not EPI.) For more information, see CICS Transaction Gateway: z/OS Administration.
For guidance about choosing a Web solution, see the IBM Redbook Revealed!
Architecting Web Access to CICS, SG24-5466, which is available from http://www.redbooks.ibm.com/redbooks/pdfs/sg245466.pdf.
CICS applications
accessing the Web
CICS Web support enables a CICS region to act as an HTTP client. A
user application program in CICS can initiate a request to an HTTP server, and receive
responses from it. CICS Web support handles the messages in response to
EXEC CICS WEB
commands in the user application program. CICS Web support is described in CICS Web support concepts and structure.