Exercise: Implementing CRUD Operations in a Java Spring Application

In this exercise, you will learn how to implement CRUD operations in SAP Cloud SDK application. We will use the Mock Server instead of the actual SAP S/4HANA Cloud.

1. Checkout the branch javaspring_v4.0_crud

   1. Run the following commands in the terminal. Make sure current working directory is /home/user/projects/cloud-sdk-learning-journey.

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      cd ~/projects/cloud-sdk-learning-journey
      git checkout -f javaspring_v4.0_crud

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2. Build and run the project

   1. 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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   2. 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. Click on the various Send Request in the requests.http file to submit GET, PUT, POST requests

   5. Verify that the response is correct for all the requests

      

4. Optional: Review code in the following source files

   1. Code walk-through

      File name	Comments on code changes
      BusinessPartnerController.java	Code logic is as follows... Annotate the class BusinessPartnerController with @RequestMapping to handle all the HTTP methods Create a variable named destination of type HttpDestination with information about the Mock Server or API Business Hub Create 5 methods getBusinessPartners, getBusinessPartner, createBusinessPartner, updateBusinessPartner, deleteBusinessPartner to handle the GET, GET/{id}, POST, PUT, DELETE requests Create an instance of the utility class to handle each of the method implementation by passing in the destination and other required values.
      GetBusinessPartnersCommand.java	Code logic is as follows... Return list of business partners No significant code change from previous branch
      GetBusinessPartnerCommand.java	Code logic is as follows... Receive both destination and id in the constructor argument Use the getBusinessPartnerByKey method by passing in the id value Use the SAP Cloud SDK fluent API method chaining to provide additional parameters
      UpdateBusinessPartnerCommand.java	Code logic is as follows... Receive destination, id and business partner details in the constructor argument Use the getBusinessPartnerByKey method by passing in the id value Use the SAP Cloud SDK fluent API method chaining to provide additional parameters Replace the FIRST_NAME property Use the updateBusinessPartner method by passing in the updated business partner object
      CreateBusinessPartnerCommand.java	Code logic is as follows... Receive destination, id and business partner details in the constructor argument Use the createBusinessPartner method by passing in the received business partner object Use the SAP Cloud SDK fluent API method chaining to provide additional parameters
      DeleteBusinessPartnerCommand.java	Code logic is as follows... Receive both destination and id in the constructor argument Use the getBusinessPartnerByKey method by passing in the id value Use the SAP Cloud SDK fluent API method chaining to provide additional parameters Return Delete method is not available message
      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. The following steps create an exact replica of the project you just checked out using Git.

   Note

   Before you execute this step, you must execute the corresponding optional step, described in the previous Implementing caching in a Java Spring application exercise.

   1. 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	Modified	Copy contents from here...
      GetBusinessPartnersCommand.java Path: ~/projects/bpstandardvdm/application/src/main/java/com/sap/cloud/sdk/tutorial/utils	Modified	Copy contents from here...
      GetBusinessPartnerCommand.java Path: ~/projects/bpstandardvdm/application/src/main/java/com/sap/cloud/sdk/tutorial/utils	New	Copy contents from here...
      CreateBusinessPartnerCommand.java Path: ~/projects/bpstandardvdm/application/src/main/java/com/sap/cloud/sdk/tutorial/utils	New	Copy contents from here...
      UpdateBusinessPartnerCommand.java Path: ~/projects/bpstandardvdm/application/src/main/java/com/sap/cloud/sdk/tutorial/utils	New	Copy contents from here...
      DeleteBusinessPartnerCommand.java Path: ~/projects/bpstandardvdm/application/src/main/java/com/sap/cloud/sdk/tutorial/utils	New	Copy contents from here...
      requests.http Path: ~/projects/bpstandardvdm	Modified	Copy contents from here...

      

   2. Build and run the project in projects/bpstandardvdm in the same exact way you did in the previous steps with project in projects/cloud-sdk-learning-journey/bpstandardvdm.