Using the CICS® JSON assistant, you can create a
service provider application from a JSON schema.
Before you begin
Before you can create a service provider application, the following conditions must be
satisfied:
- Your web services description must be in a UNIX file in
z/OS® and you must create a suitable provider mode pipeline in
the CICS region.
- You must define to OMVS the user ID under which DFHJS2LS runs.
- The user ID must have read permission to z/OS
UNIX and PDS libraries and write permission to the directories
specified on the LOGFILE, WSBIND,
JSON-SCHEMA-REQUEST, JSON-SCHEMA-RESPONSE, and
JSON-SCHEMA-RESTFUL parameters.
- You must allocate sufficient storage to the user ID for the ID to run Java™ . You can use any supported version of Java . By default, DFHJS2LS uses the Java version
specified in the JAVADIR parameter.
About this task
You can use the JSON assistant to create language structures from your JSON schema for the
service provider application.
Procedure
-
Use the DFHJS2LS batch program to generate a web service binding file and one or more language
data structures.
DFHJS2LS contains a large set of optional parameters that provide you with flexibility to
create the binding file and language structures that your application requires. Consider these
options when you enable an existing application for web services:
- Which mechanism will CICS use to pass data to the service
provider application program? You can use channels and pass the data in containers or use a
COMMAREA. Channels and containers are recommended. Specify them with the PGMINT
parameter.
- Which language do you want to generate? DFHJS2LS can generate COBOL, C/C++, or PL/I language
data structures. Specify the language using the LANG parameter.
- Which mapping level do you want to use? The higher the mapping level, the more control and
support you have available for the handling of character and binary data at run time. Some optional
parameters are available only at the higher mapping levels. You are recommended to use the highest
level of mapping available. Specify the mapping level with the MAPPING-LEVEL
parameter.
- Which URI do you want the web service requester to use? Specify a relative URI using the
URI parameter; for example,
URI=/my/test/webservice. The value
is used by CICS when it creates the URIMAP resource.
- Under which transaction and user ID will you run the web service request and response? You can
use an alias transaction to run the application to compose a response to the service requester. The
alias transaction is attached under the user ID. Specify it with the
TRANSACTION and USERID parameters. These values are used
when creating the URIMAP resource. If you do not want to use a specific transaction, do not use
these parameters.
When you submit DFHJS2LS, CICS generates the web
service binding file and places it in the location that you specified with the
WSBIND parameter. The language structures are placed in the partitioned data
set that you specified with the PDSLIB parameter.
-
Copy the generated web service binding file to the pickup directory of the
provider mode PIPELINE resource that you want to use for your web service application.
You must copy the binding file in binary mode.
-
Write a service provider application program to interface with the generated language
structures and implement the required business logic.
-
Use the PIPELINE SCAN command to dynamically create the WEBSERVICE resource
and a URIMAP resources.
- The WEBSERVICE resource encapsulates the web service binding file in CICS and is used at run time.
- The URIMAP resource provides CICS with the information to
associate the WEBSERVICE resource with a specific URI.
Alternatively, you can define the resources yourself, although this is not recommended.