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Customizing and Running Code

  1. Expand the downloaded zip file and open the project in a Java IDE (we recommend IntelliJ IDEA).
  2. The project already includes the CodeRunner™ SDK. The directory where you unzip the project file will be further referenced as [project-home]in this guide. The CodeRunner™ SDK distribution (which is included into the zip) has the following structure:
    /bin - contains utilities for debugging and deploying custom code.
    /classes - directory which СodeRunner™ uses by default when it looks for custom business logic code to debug or deploy.
    /libs - may contain additional Java dependencies (.jar files) which will be added to the deployment.
  3. The downloaded project uses[project-home]/classes as the directory for the compiled output. This is important as the /classes directory is automatically recognized by CodeRunner™ when it looks for custom code.
  4. Open and modify as shown below (adding the code into the beforeCreate method):
    import com.backendless.servercode.RunnerContext;
    import com.backendless.servercode.annotation.Asset;
    import com.backendless.servercode.extension.PersistenceExtender;
    import com.coolapp.models.Order;
    * OrderTableEventHandler handles events for all entities. This is accomplished
    * with the @Asset( "Order" ) annotation. 
    * The methods in the class correspond to the events selected in Backendless
    * Console.
    @Asset( "Order" )
    public class OrderTableEventHandler extends PersistenceExtender<Order>
      public void beforeCreate( RunnerContext context, Order order) throws Exception
        System.out.println( "About to insert modified Order object into the data store" );
        String customerName = order.getCustomername();
        System.out.println( "customer name received from client - " + customerName );
        order.setCustomername( customerName.toUpperCase() );
        System.out.println( "customer name after the change - " + order.getCustomername() );

  5. Compile the code and make sure [project-home]/classes contains the following directory structure:
  6. Open a command prompt window and change the current directory to [project-home]/bin.
  7. Run the CodeRunner™ script as shown below:
    on Linux:

    on Windows:
  8. Once CodeRunner™ starts, it produces the following output:

[INFO] JDK from "JAVA_HOME" - /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home
[INFO] CodeRunner(tm) Backendless Debugging Utility
[INFO] Copyright(C) 2017 Backendless Corp. All rights reserved.
[INFO] Version: 4.0.0 Build date: 2017-05-18T11:27:43Z
[INFO] CodeRunner session is running for 2 hours and will be terminated on 21:40:58.239[UTC]
[INFO] Registering runner on: ''
[INFO] Runner successfully registered
[INFO] Parsing event model...
[INFO] Build successfully: 1 handler, 0 timers
[INFO] Deploying model to server, and starting debug...
[INFO] Model successfully deployed.
[INFO] Waiting for events...

  1. At this point CodeRunner™ is connected to Backendless and the code is ready for local debugging. Return to Backendless Console, click the Business Logic icon, select EVENT HANDLERS:
  2. To test the code you must issue an API request to store an object in the Order table. You could write a client application using any of the Backendless SDKs or with the REST API. Backendless Console includes a REST Console, which is a graphical interface for creating Data Service REST requests. Click the Data icon, select the Order table and then click REST Console.
  3. Enter the following text into the Request Body area and click the POST button. This will send a REST API request to create an object in the Order table:

 "customername":"Acme Corp"  
1. You will see the following response in Response Body. As you can see the name of the customername property is no in upper case, which is the change made by the event handler:
event-handler-in-action.zoom70 1. Also notice the following output in the window where CodeRunner™ runs. The output comes from the custom code you developed:

About to insert modified Order object into the data store
customer name received from client - Acme Corp
customer name after the change - ACME CORP

  1. You can also see the created object in the Data Browser in console: