Introduction

This exercise will develop your skills with OpenLegacy IDE by generating Java models from existing sources and creating unit tests to validate backend connectivity and data.

Pre-Requirements

OpenLegacy IDE(Full installation including JDK and all Maven dependencies).
Internet Connection
SAP JCo

In order to do this guide, you need to have SAP Java connector (SAP JCo).
OpenLegacy can't provide the files due to the SAP license policy.
SAP JCo can be downloaded from the official SAP website after signing in with an SAP account
The files should be copied/installed into .m2/repository/com/sap folder
Run the IDE as Administrator

Running the IDE as administrator will allow us to make changes to openlegacy.ini file using the IDE. If not possible, add the following line to your openlegacy.ini file:
-Dsap.jco=<PATH-TO-SAPJCO-FOLDER>/sapjco-3.0.14.jar

Exercise Definition

Configure IDE to work with sapjco.jar
Add SAP JCo dependency to the local maven repository
Create a new SDK Project.
Import BAPI Model using BAPI Fetcher
Develop unit tests on the fly.
Test the connectivity and data retrieval from the SAP host.

Step 1 – Create a New SDK Project

First, we will create a new SDK project using the OpenLegacy IDE.
The purpose of the SDK project is to allow easy access to legacy backends, using standard and easy to use Java code.

Project Setup

Create a new OpenLegacy SAP RPC project.

Unzip sapjco.zip
Move sapjco folder to your local maven repository and place it in ./m2/repository/com/sap - if sap folder doesn't exist create a new folder and name it sap.
Open the New Project Wizard (you have three options):
- File → New → OpenLegacy SDK Project
- Alt+Shift+N → OpenLegacy SDK Project
- File → New → Project → Select OpenLegacy SDK Project from the drop-down
Define the project name and the default package
Select Mainframe SAP as the backend and click Next
If prompted, choose the sapjco.jar file location, restart your IDE and follow steps 3-5
Enter the following SAP host credentials:
- Hostname: 91.195.162.68
- Username: user02
- Password: open1234
- Client: 800
- System Number: 04
- Language: en
- Leave Router field empty
These credentials can be edited easily in the properties file located at src/main/resources/application.yml file.
Click Finish

Testing the Configuration

Make sure your environment has no errors.
Do a Maven update if needed.
Do a project -> clean if needed (not Maven clean).

Congratulations! You are ready to start working on the API.

Step 2 – Generate Java Model (Entity) from the BAPI File

Let's create Java models out of our demo BAPI file.

Right-click on project name → OpenLegacy → Import BAPI definition
Set the BAPI Name field, with BAPI_CUSTOMER_GETSALESAREAS
Check Generate JUnit Test checkbox
Click OK

Step 3 – Create a JUnit Test

OpenLegacy enables test-driven development by auto-generating test suites for each backend program (entities).
We can extend this test suite with additional unit tests to validate our connectivity to the backend.

Go to src/test/java/tests/BapiCustomerGetsalesareasTest.java

Add a PrintJson method to print the response retrieved from the backend:

Print Json

public static void printJson(Object object) {
		ObjectMapper mapper = new ObjectMapper();
		mapper.configure(SerializationFeature.INDENT_OUTPUT, true);
		try {
			System.out.println(mapper.writeValueAsString(object));
		} catch (JsonProcessingException e) {
			System.out.println(e.getMessage());
		}
	}

Press Ctrl+Shift+O to automatically organize the imports and add missing classes

Implement a simple unit test to validate connectivity to the SAP host and retrieve Customer Sales Areas Info:

BapiCustomerGetsalesareasTest

	@Test
	public void testBapiCustomerGetsalesareasEXECUTE() throws Exception {
		try {
			BapiCustomerGetsalesareas bapiCustomerGetsalesareas = new BapiCustomerGetsalesareas();
			bapiCustomerGetsalesareas.setCustomerno("FIO-CUST01");
			bapiCustomerGetsalesareas = rpcSession.doAction(RpcActions.EXECUTE(), bapiCustomerGetsalesareas);
			assertNotNull(bapiCustomerGetsalesareas);
		} finally {
			rpcSession.disconnect();
		}
	}

Click F11 to run the JUnit Test

Conclusion

You learned how to create a Java entity from SAP BAPI.
An example of a result project can be found here:

Notes

When creating an API project that uses SAP backend projects, we should always copy the sapjco-3.0.14.dll and sapjco-3.0.14.jar files to the API project root folder.