Exercise: Querying SAP APIs in a Java Spring application

In this exercise, you will learn how to query the Business Partner API of SAP S/4HANA Cloud. We will use the Mock Server instead of the actual SAP S/4HANA Cloud.

1. Clone the SAP Cloud SDK Samples repository and checkout the branch javaspring_v1.0_query in SAP Business Application Studio

   1. Open SAP Business Application Studio.

   2. Run the following commands in the terminal

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      cd ~/projects
      git clone https://github.com/SAP-samples/cloud-sdk-learning-journey.git
      cd cloud-sdk-learning-journey
      git checkout javaspring_v1.0_query

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2. Build and run the project

   1. Open the cloud-sdk-learning-journey folder in the workspace

      

   2. Build the application by running the following commands in the terminal

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      cd bpstandardvdm
      mvn clean install -Dmaven.test.skip=true

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   3. Open the Application.java file. Press F5 to run the application

      

3. Query the Business Partner API of SAP S/4HANA Cloud

   1. Open the requests.http file

   2. Click on Send Request in the requests.http file to submit the GET request for business partners

   3. Verify that the list of business partners are returned from the Mock Server. Note: If the Mock Server is not running, make sure to run the Mock Server on port 8081 by following the prerequisites at the top

   4. Optional: Open BusinessPartnerController.java file in the controllers folder. Uncomment section of code to replace the URL property with https://sandbox.api.sap.com/s4hanacloud to retrieve business partners from SAP API Business Hub. Note that you also have to provide the API KEY

      

      

   5. Optional: Uncomment section of code to replace the URL property with https://my######.s4hana.ondemand.com to retrieve business partners from SAP S/4HANA Cloud

4. Optional: Review code in the following source files

   1. Note

      Check out the exercise on SAP Tutorial Navigator on Connecting to OData Service on Cloud Foundry using SAP Cloud SDK. https://developers.sap.com/tutorials/s4sdk-odata-service-cloud-foundry.html

      Code walk-through

      File name	Comments on code changes
      BusinessPartnerController.java	Code logic is as follows... Annotate the method getBusinessPartners with @RequestMapping to handle the GET method Create a variable named destination of type HttpDestination with information about the Mock Server or API Business Hub Create an instance of the DefaultBusinessPartnerService class Call the getAllBusinessPartner method to retrieve the business partners Use the SAP Cloud SDK fluent API method chaining to provide additional parameters Return the list of business partners as part of the GET request
      requests.http	Provides various HTTP requests that can be submitted to query the Business Partner API
      commands.txt	Provides various commands that can be run on the terminal

5. Optional: Manually create the project

   1. Generate a Spring Boot project using SAP Cloud SDK from scratch using the Maven archetype. Run the following command in the terminal

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      cd ~/projects
      mvn archetype:generate "-DarchetypeGroupId=com.sap.cloud.sdk.archetypes" "-DarchetypeArtifactId=scp-cf-spring" "-DarchetypeVersion=RELEASE" "-DartifactId=bpstandardvdm" "-DgroupId=com.sap.cloud.sdk.tutorial" "-Dpackage=com.sap.cloud.sdk.tutorial"

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   2. Open the bpstandardvdm folder in the workspace. Create or update the following files in the table below

      

      File name	Type	Contents
      BusinessPartnerController.java Path: ~/projects/bpstandardvdm/application/src/main/java/com/sap/cloud/sdk/tutorial/controllers	New	Copy contents from here...
      requests.http Path: ~/projects/bpstandardvdm	New	Copy contents from here...