Tutorial: CICS Web Service Provider from JSON, RESTful

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 BookWeb service provider section of this tutorial, we recommend that you install a JSON requester tool.

Create the BookREST project

Use the CWSProject demonstration project to create a project for your CICS Web service provider.

1. Using Windows Explorer or at a command prompt, create a project directory named BookREST.
2. Extract the CICSWebServicesProjectTemplate_VS.zip file, located in the %PUBLIC%\Documents\Micro Focus\Enterprise Developer\Samples\Mainframe\CICS\Classic\CWS directory by default, to the new BookREST project directory.
3. From the Enterprise Developer for Visual Studio 2019 main menu, click File > Open > Project/Solution.
4. Browse to the new BookREST project directory, and select the CWSProject.cblproj project file; then click Open. This starts the Solution Explorer.

   Here, you rename the project to match the name of the service interface you are going to create. This is not mandatory in general, but done here to differentiate between tutorial projects.

5. In the Solution Explorer, right-click the CWSProject project; then select Rename.
6. Type BookREST; then press Enter.

Generate CICS Web Service provider components

Use the Generate Web Service dialog box to generate the components of your Web service provider.

Generate and move the BookREST.wsbind file

1. In the Solution Explorer, right-click the BookREST.svi file; then select Generate WSBIND.

   Because the BookREST.wsbind file is generated to the BookREST project's json\BookREST directory, but the output path is set to the BookREST project's loadlib directory, you need to move the file from the project's json\BookREST directory to the project's loadlib directory so that Enterprise Server finds the correct file.

2. Using Windows Explorer or at a command prompt, change to the BookREST project directory.
3. Copy or move the BookREST.wsbind file from the json\BookREST directory to the loadlib directory.

Implement the service

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

• It retrieves the type of request being made from the DFHHTTPMETHOD container, and evaluates it.
• For a GET request, it populates the DFHWS-DATA container with the content of the response data structure (in film01.cpy).
• For a POST or PUT request, it populates the request data structure (in BookR01.cpy) with the contents of the DFHWS-DATA container.

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

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

   01 ws-function                 pic x.
   01 ws-file-status              pic xx value "00".

3. Scroll down to the when "GET" statement, and add the following lines between it and the move "DFHWS-DATA" to ls-container-name statement:

                  initialize lnk-b-details
                  move "1" to ws-function
                  move ls-uri-resid to lnk-b-stockno
                  call "book" using ws-function
                                    lnk-b-details
                                    ws-file-status

   Note: BookREST.cbl contains a comment line between the two statements. You can replace the comment line with this block of code.
4. At the next commented line below an EXEC CICS GET statement, add the following lines to create a new record:

                  move "2" to ws-function
                  call "book" using ws-function
                                    lnk-b-details
                                    ws-file-status

5. Near the bottom of the program, in the second MOVE statement in the put-DFHRESPONSE paragraph, replace the ls-uri-resid variable with the ws-file-status variable.
6. Click File > Save BookREST.cbl.
7. Close the COBOL editor.

Build the BookREST project

• From the Solution Explorer, right-click the BookREST project; then select Build.

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 for Visual Studio 2019, activate the Server Explorer.
2. Expand Micro Focus Servers.
3. Right-click localhost; then select New Enterprise Server.
4. In the Name field, type CWSREST. This is the name for the new enterprise server region.
5. Click the browse button that corresponds to the Template field, and navigate to the CICSWebServicesTemplate.xml file located in the BookREST\ESTemplates project folder.
6. Double-click CICSWebServicesTemplate.xml. This populates the Template field.
7. On the list next to Associate with projects, check BookREST.
8. Click OK.

   The Server Explorer should now show the CWSREST enterprise server region listed under localhost.

   Note: If CWSREST doesn't immediately appear, right-click Micro Focus Servers; then select Refresh from the context menu.

Configure CWSREST 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.

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 CICSWebServicesTemplate used to create the CWSREST region does not include these resources on the startup list; 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 a resource group to contain the resources required by the BookREST program, and also add the new group to the startup list.

Start Enterprise Server Administration

1. From Server Explorer, right-click Micro Focus Servers; then select Administration. This starts Enterprise Server Administration.

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

2. Back on the Server Explorer, right-click CWSREST; 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 CWSREST has started, on the Administration Home page, click the Details button located in the Status column for the CWSREST 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 CWSREST 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

Here, you add the DFHWEB and DFHPIPE resource groups to the startup list, and add the CWSRESTP resource group name to the startup list. At this point, you have you have neither created nor defined the CWSRESTP group and its respective resources. 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 CWSRESTP; then click Apply.

Create the CWSRESTP 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 CWSRESTP.
4. In the Description field, type CICS Web Services JSON Provider Resources; then click Add. This invokes the CICS Group CWSRESTP page where you can create and define resources for the group.

Define CWSRESTP resources

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

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

   Name	RSTTCPIP
   Description	My TCP/IP Service
   Port No	5639

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 CWSRESTP page.
6. Click Pipeline.
7. Complete these fields:

   Name	RESTPIPE
   Description	My CICS 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\jsonjavaprovider.xml	The IDE_XML_LOC environment variable in CWSREST points to the xml project folder.1
   WebSvc Dir	$IDE_LOADLIB\	The IDE_LOADLIB environment variable points to the loadlib project folder.1
   1 To see a list of environment variables defined for CWSREST, 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 CWSREST; then select Restart. This stops and then starts the CWSREST enterprise server region, automatically installing and loading the newly added resources on the startup list.

Verify Resources

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

1. In Enterprise Server, start ESMAC for the CWSREST 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 BookREST Web service listed and marked as INSERVICE.
4. On the ESMAC menu, click Pipeline; then click the Details button that corresponds to RESTPIPE. 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/BookREST/*.

   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 RESTful CICS Web service, you can either send an HTTP GET request to retrieve an existing Book record or an HTTP PUT request to create a new Book record. The request is sent 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 Book Web service provider

Now that you have your Web service provider running with all of its resources active, you are ready to send a GET 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:5639/cics/services/BookREST/1111

2. Set the Method to GET.

   You should receive the following JSON response:

   {"book": {"lnk_b_details": {
      "lnk_b_text_details":    {
         "lnk_b_title": "LORD OF THE RINGS",
         "lnk_b_type": "FANTASY",
         "lnk_b_author": "TOLKIEN"
      },
      "lnk_b_stockno": "1111",
      "lnk_b_retail": 15,
      "lnk_b_onhand": 4000,
      "lnk_b_sold": 3444
   }}}

3. Set the Method to PUT and remove the last five characters from the endpoint URL, so that it now reads:

   http://localhost:5639/cics/services/BookREST

4. Enter the following JSON request and send it to create a new Book record:

   {"book": {"lnk_b_details": {
      "lnk_b_text_details":    {
         "lnk_b_title": "HARRY POTTER",
         "lnk_b_type": "FANTASY",
         "lnk_b_author": "ROWLING"
      },
      "lnk_b_stockno": "5555",
      "lnk_b_retail": 20,
      "lnk_b_onhand": 6000,
      "lnk_b_sold": 4555
   }}}

   You should receive a response of 00 to show that the record has been added successfully.

5. Set the Method to GET again and add /5555 to the endpoint URL.

   You should receive a response that matches the JSON you sent in the PUT request.