How to use the data I receive from Azure IoT Hub

Question

So, this is my code for receiving data from the Azure Cloud:

public void accept(PartitionReceiver receiver)
{
    System.out.println("** Created receiver on partition " + partitionId);
    try {
        while (true) {
            Iterable<EventData> receivedEvents = receiver.receive(10).get();
            int batchSize = 0;
            if (receivedEvents != null)
            {
                for(EventData receivedEvent: receivedEvents)
                {                                    
                    System.out.println(String.format("| Time: %s", receivedEvent.getSystemProperties().getEnqueuedTime()));
                    System.out.println(String.format("| Device ID: %s", receivedEvent.getProperties().get("iothub-connection-device-id")));
                    System.out.println(String.format("| Message Payload: %s", new String(receivedEvent.getBody(), Charset.defaultCharset())));
                    batchSize++;
                }
            }
        }
    } catch (Exception e)
    {
        System.out.println("Failed to receive messages: " + e.getMessage());
    }
}

This is where I get the product name and price as a payload:
System.out.println(String.format("| Message Payload: %s", new String(receivedEvent.getBody(), Charset.defaultCharset())));

But now I need to take the Payload and store its product into a string object and the price into a double variable. How do I do that? Please suggest!

Answer 1

The payload you receive will be a JSON string. So, you could define a POJO class to package the data and then deserialize to the appropriate object and use it. Serilize and deserialize the data as event body between a POJO and JSON string by using a json library. You can choose any library you want from here: http://www.json.org/.

This is the code to receive :

public class Product {
public Product(){

}
    private String product;
    private Double price;

public Product(String json ){
    Gson gson=new Gson();
    try{
        Product product =gson.fromJson(json, Product.class);
        if (product!=null){
            System.out.println("Name: " +product.getProduct());
        }
    }catch (Exception e){
        System.out.println("failed: " +e.getMessage());
    }
}

    public String getProduct() {
        return product;
    }

    public Double getPrice() {
        return price;
    }
 }
And, this is how you can read the JSON String into a Object from the Class Product. Hence, the Product class will contain variables with product and price!

    public Product(String json ){
    Gson gson=new Gson();
    try{
        Product product =gson.fromJson(json, Product.class);
        if (product!=null){
            System.out.println("Name: " +product.getProduct());
        }
    }catch (Exception e){
        System.out.println("failed: " +e.getMessage());
    }
}