Tutorial: CICS Web Service Provider from JSON, Request-Response Top-down Method

Prerequisites

If you have not done so already, you must install the IBM-37, IBM-437, and 002501B5 CCSID tables before attempting this tutorial. See To install CCSID tables for instructions.

To complete the Test the ReverseJSON Web service provider section of this tutorial, we recommend that you install a JSON requester tool.

This tutorial assumes that your Enterprise Developer project is set to Build Automatically. If not, turn this feature on by clicking Project > Build Automatically from the main menu.

Import the ReverseJSON project

1. In Eclipse, start the Team Developer Application Explorer.
2. From the main menu, click File > Import.
3. Expand General, and select Existing Projects into Workspace; then click Next.
4. Select Set root directory, then browse to the %PUBLIC%\Documents\Micro Focus\Enterprise Developer\Samples\Mainframe\CICS\Classic\CWS\JSON\Provider\TopDown directory; then click Select Folder.
5. On the Projects list, ensure that ReverseJSON is checked.
6. Under Options, check Copy projects into workspace; then click Finish.

   The Application Explorer now shows the ReverseJSON project, which is created in a ReverseJSON subdirectory of your current Eclipse workspace, and is built automatically.

Generate CICS Web Service provider components

Use the New CICS Web Service wizard to generate the components of your Web service provider.

1. From the Application Explorer, click the ReverseJSON project to select it.
2. Click File > New > CICS Web Service. This starts the New CICS Web Service Wizard.
   Note: If CICS Web Service is not listed:

   1. Select Other.
   2. Expand Micro Focus Service Interface.
   3. Select CICS Web Service; then click Next.
3. Under Service type, select JSON message processing.
4. From the drop-down list, select CICS Web Service Provider (Top-Down, Request-Response); then click Next.

   The Project field is already populated with the name of the current project, ReverseJSON.

5. Click the Browse button that corresponds to the JSON request field.
6. Navigate to and select the reverse.json file, located in your project's schema folder.
7. Click the Browse button that corresponds to the JSON response field.
8. Navigate to and select the reverse.json file, located in your project's schema folder.

   You need to provide a URI that Enterprise Server can use to identify and locate the appropriate Web service upon receiving a request or a response. This information goes into the Service location field.

9. In the Service location field, type /cics/services/json/reverse.
10. Select CHANNEL from the Program interface drop-down list.

    The default container name is DFHWS-DATA, which is the top-level container used in service provider applications for CICS Web services.

11. Click Next.
12. In the Output artifacts group, type reverseJ into the Program name field. This is the name of the generated COBOL skeleton program.

    The file prefixes you supply for the Request file prefix and Response file prefix fields become the first part of the filenames of the generated copybooks that support the generated skeleton program file; one for request data structures, and one for response data structures.

13. In the Request file prefix field, type REQ.
14. In the Response file prefix field, type RESP.

    Enterprise Developer generates a WSBIND file that maps the JSON request to the data structure in the generated request copybook and maps the JSON response to the data structure in the generated response copybook. You need to provide a folder and filename for this file.

15. Click the Browse button that corresponds to the WSBIND file field.
16. On the Browse for WSBIND file dialog, click New folder.
17. In the field for the folder name, overwrite New folder with loadlib; then press Enter.
18. Double-click the loadlib folder.
19. In the File name field, type ReverseJ; then click Open.
20. Click Finish.

Enterprise Developer generates the following CICS Web service components:

reverseJ.cbl

A skeleton CICS program.

reverseJ.svi

A service interface file.

REQ01.CPY

A copybook containing the COBOL data structures required to send a JSON request as input. This file is generated but does not appear in the Solution Explorer.

RESP01.CPY

A copybook containing the COBOL data structures required to receive a JSON response message as output.

Implement the service

The generated skeleton program, reverseJ.cbl, contains some basic functionality that is common to any CICS Web service that uses the Channel interface. The Web service:

• Populates the request data structure (in REQ01.CPY) with the content of the DFHWS-DATA container.
• Populates the DFHWS-DATA container with the content of the response data structure (in RESP01.CPY).

To provide the required operation logic, you must code it manually by editing the program.

1. From the Application Explorer, double-click reverseJ.cbl to open it in the COBOL editor.
2. Declare the following two variables in the Working-Storage section:

   01 ws-string-len               pic x(4) comp-5.
   01 ws-reversedString-len       pic x(4) comp-5.

   The provided revLogicJ.cpy copybook contains one PERFORM statement that populates the request and response data structures. You need to include the copybook in the program and execute the PERFORM statement.

3. reverseJ.cbl contains two comment lines between the EXEC CICS GET and the EXEC CICS PUT statements. Code the following PERFORM statement between the comment lines:

   perform reverse-logic

4. Scroll down to the bottom of the program, and add the following copy statement after the exit program statement:

   copy 'revLogicJ.cpy'.

5. Click File > Save.
6. Close the COBOL editor.

   Eclipse automatically builds the project to include your changes.

Create an enterprise server region

Here you use Enterprise Server to create an enterprise server region on which to run the Web service.

1. In Enterprise Developer, activate the Server Explorer.
   Note: If Server Explorer is not showing, click Window > Show View > Other > Micro Focus > Server Explorer.
2. Right-click Local [localhost:86]; then select New > Enterprise Server.
3. In the Name field, type JSONPROV. This is the name for the new enterprise server region.
4. Click the Browse button that corresponds to the Template field, and navigate to the CICSWebServicesTemplate.xml file located in the ReverseJSON project folder.
5. Double-click CICSWebServicesTemplate.xml. This populates the Template field.
6. On the list next to Associate with projects, check ReverseJSON.
7. Click Finish.

   The Server Explorer should now show the JSONPROV enterprise server region listed under Local [localhost:86].

   Note: If JSONPROV is not showing, expand Local [localhost:86].

Configure JSONPROV resources

All enterprise server regions require access to certain resources, depending on the types of applications they run. Resources that are defined on a region's startup list are loaded during the startup routine, making them available for as long as the region is running.

JSON CICS Web services use the underlying resources provided by the standard Enterprise Server CICS Web interface (CWI) and CICS Web Services (CWS) support. However, the resource definition file supplied with the project does not include these resources; therefore, you need to add them manually. The CWI resources reside in a predefined resource group named DFHWEB. The CWS resources are in the predefined DFHPIPE group.

In addition, you need to create and define a resource group, JSONPROV, to contain the resources required by the reverseJ program.

Start Enterprise Server Administration

1. From Server Explorer, right-click Local [localhost:86]; then select Open Administration Page. This starts Enterprise Server Administration.

   On the Home page, you should see the JSONPROV enterprise server region listed.

2. Back on the Server Explorer, right-click JSONPROV; then select Start.

   As the region is starting, the Enterprise Server Administration Home page should show log information in the region's Status Log column. When the region is fully started, this is indicated in the region's Status column.

   Note: If this is the first time you have started the server you see a sign-on dialog box. If Server is secured is checked, uncheck it; then click OK. Unchecking Server is secured prevents this dialog box from showing when you subsequently start the region. If Server is secured is not checked, simply click OK to clear the dialog box. If a Secure Storage prompt appears, click No.

Start ES Monitor and Control (ESMAC)

1. After JSONPROV has started, on the Administration Home page, click the Details button located in the Status column for the JSONPROV region.
2. On the Server > Control page, click ES Monitor & Control. This starts the ESMAC utility where you can edit the startup list.

Open the DEMOSTRT startup list

1. On the ESMAC menu, click the drop-down list located under Resources; then select by Group.
2. Click Startup. This invokes a list of CICS Startup Lists in the right pane.

   The JSONPROV region uses the default startup list, named DEMOSTRT.

3. Click the Details button that corresponds to DEMOSTRT. This takes you to the CICS STARTUP - DEMOSTRT page.

Add resource groups

CICS Web Services are built on top of the CICS Web Interface (CWI) support, so you need to ensure that all CWS and CWI resources are available. These reside in the DFHPIPE and DFHWEB resource groups respectively, which are already defined, but not included in the startup list. Here you add these resource groups to the startup list.

In addition, you need to add a new resource group for the CICS provider resources named JSONPROV. At this point, the JSONPROV resource group is neither created nor defined. Those tasks are completed in the next few sections of this tutorial.

1. On the CICS STARTUP - DEMOSTRT page, scroll down to the end of the list and type DFHWEB into the empty field at the bottom; then click Apply. ESMAC adds the DFHWEB group, and adds another empty field at the end of the list.
2. In the new empty field, type DFHPIPE; then click Apply.
3. In the new empty field, type JSONPROV; then click Apply.

Create the JSONPROV resource group

1. On the ESMAC menu, click the Groups button located under Resources.
2. On the CICS Resource Groups page, click New.
3. In the Name field, type JSONPROV.
4. In the Description field, type CICS Web Services Provider Resources; then click Add. This invokes the CICS Group JSONPROV page where you can create and define resources for the group.

Define JSONPROV resources

The reverseJ program requires a resource for TCP/IP service, and a resource to support a pipeline.

1. On the CICS Group JSONPROV page, click TCPIPSv.
2. Complete these fields:

   Name	CWSTCPIP
   Description	My TCP/IP Service
   Port No	5482

3. Click Add. Enterprise Server returns Add successful.
4. Click Apply. Enterprise Server returns Update successful.
5. Click Group List to return to the CICS Group JSONPROV page.
6. Click Pipeline.
7. Complete these fields:

   Name	JSONPIPE
   Description	My CICS JSON Provider Pipeline
   Resp Wait	DEFT	This is the number of seconds that an application waits for a response from the service. DEFT indicates the default value, which is 10 seconds for HTTP and 60 seconds for MQ.
   Config file	$IDE_XML_LOC\JSONConfig.xml	The IDE_XML_LOC environment variable in JSONPROV points to the xml project folder.1
   WebSvc Dir	$IDE_LOADLIB\	The IDE_LOADLIB environment variable points to the loadlib project folder, which contains the WSBIND file.1
   1 To see a list of environment variables defined for JSONPROV, from the ESMAC menu, click Env.Vars..

8. Click Add. Enterprise Server returns Add successful.
9. Click Apply. Enterprise Server returns Update successful.
10. Click Home to return to the Administration Home page.

    You can install the new resources by stopping and starting the region.

11. From the Enterprise Developer Server Explorer, right-click JSONPROV; then select Restart. This stops and then starts the JSONPROV enterprise server region, automatically installing and loading the newly added resources on the startup list.

Verify Resources

After JSONPROV is started, you can verify that the resources you have defined are installed and active.

1. In Enterprise Server, start ESMAC for the JSONPROV region.
2. On the ESMAC menu, select Active from the drop-down list located under Resources.
3. On the ESMAC menu, click the WebSvc button. You should see the ReverseJ Web service listed and marked as INSERVICE.
4. On the ESMAC menu, click Pipeline; then click the Details button that corresponds to JSONPIPE. The Pipeline resource sets the response wait period, identifies the JSON configuration file, and the Web Service directory.
5. On the ESMAC menu, click URIMAP; then click the Details button that corresponds to PIPELINE and /cics/services/json/reverse.

   Enterprise Server generates URIMAPs to provide CICS with the information it needs to process requests. The name of each generated URIMAP begins with a pounds sterling symbol (£).

   To run your provider CICS Web service, you send a JSON request to an endpoint URL that routes the request to your enterprise server region. The endpoint URL contains a URI value. The incoming request reads the installed URIMAPs to identify the map whose Path value matches the URI value of the endpoint URL. When the correct URIMAP is identified, CICS uses the data defined in the URIMAP, such as the name of the Web Service and its associated Pipeline, to process the request.

Test the ReverseJSON Web service provider

Now that you have your Web service provider running with all of its resources active, you are ready to send a JSON request to run the Web service. You can do this using any JSON requester tool.

1. Create a JSON request with the following endpoint URL:

   http://localhost:5482/cics/services/json/reverse

2. Set the Method to POST.
3. Enter the following JSON request:

   {"InputStrings" : {"myStrings":"olleH"}}

   You should receive the following JSON response:

   {"OutputStrings" : {"myStrings":"Hello"}}