Avoiding a NPE when checking JSON response using JsonPath and Rest Assured

Question

Given the following JSON:

{
    "priceOne": 1034,
    "priceTwo": null,
    "priceThree": 7282,
}

...and the following Rest Assured method to get the priceTwo value and set to a specific value:

public void getPrice() {

    setPriceService();

    Response response =
            given().
                    spec(priceServiceRequestSpec)
    when().
            get("api/v1/prices/102934").
                    then().extract().response();

    if (StringUtils.isNotEmpty(response.path("priceTwo").toString())) {
        vehicle.setPrice(response.path("priceTwo").toString());
        return true;
    } else {
         vehicle.setPrice("2000");
    }
}

...I am getting a NullPointerException when I expect the StringUtils.isNotEmpty to handle this. I expect this is down to the way I am using the response.path as a paramater. What is a better way of achieving this?

Answer 1

String response =RestAssured.get("https://praveendvd.free.beeceptor.com/test").
                        then().extract().response().asString();
    
JSONObject jsonObj = new JSONObject(response);
       
int val = (jsonObj.isNull("priceTwo")) ? 2:jsonObj.get("priceTwo");
vehicle.setPrice(val);

you can directly pass without creating a variable also:

vehicle.setPrice((jsonObj.isNull("priceTwo")) ? 2:jsonObj.get("priceTwo"));

use JsonObject has method and ternary operator java

Answer 2

Response response =RestAssured.get("https://praveendvd.free.beeceptor.com/test").
                    then().extract();

if (StringUtils.isNotEmpty(response.path("priceTwo").toString())) {
    vehicle.setPrice(response.path("priceTwo").toString());
    return true;
} else {
     vehicle.setPrice("2000");
}

You should creating a variable and also most probablity, you have a type casting problem that Response type to convert String for condition.

Answer 3

Since the path returns a reference type you can just use the construction like this:

if (response.path("priceTwo") instanceof Number) {
    vehicle.setPrice(response.path("priceTwo").toString());
    return true;
} else {
     vehicle.setPrice("2000");
}

Below is the test:

public class Test {

    public static void main(String[] args) {
        Response response = RestAssured
                .get("https://60269516186b4a0017780505.mockapi.io/rest_assured_nulls");
        handleJson(response, "[0].priceOne");
        handleJson(response, "[0].priceTwo");
        handleJson(response, "asdfe");

    }

    private static void handleJson(Response response, String path){
        if (response.path(path) instanceof Number) {
            System.out.println("Valid number: " + response.path(path).toString());
        } else {
            System.out.println("Invalid number so setting default value");
        }
    }
}

which outputs:

Valid number: 1034
Invalid number so setting default value
Invalid number so setting default value

for my test endpoint