Hello I have some problem with the <https://docs.spring.io/spring-hateoas/docs/1.1.0.RELEASE/referen...

# spring

[marzelwidmer]

Hello I have some problem with the https://docs.spring.io/spring-hateoas/docs/1.1.0.RELEASE/reference/html/#server.affordances implementation in Kotlin. have maybe somebody this done already ?

[kqr]

not really but you should describe your problem

[marzelwidmer]

makes sense. will update it. my questions 🙈

[marzelwidmer]

I was trying to Kotlinies the following

https://youtu.be/nVEmfmdDUXU▾

[kqr]

but we still don't know what is your issue?

[kqr]

what's the error?

[marzelwidmer]

i will post it later. AFK at the moment

[marzelwidmer]

: Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.aop.framework.AopConfigException: Unexpected AOP exception; nested exception is java.lang.NullPointerException] with root cause

java.lang.NullPointerException: null
	at org.springframework.aop.framework.CglibAopProxy.doValidateClass(CglibAopProxy.java:257) ~[spring-aop-5.3.3.jar:5.3.3]
	at org.springframework.aop.framework.CglibAopProxy.doValidateClass(CglibAopProxy.java:280) ~[spring-aop-5.3.3.jar:5.3.3]
	at org.springframework.aop.framework.CglibAopProxy.validateClassIfNecessary(CglibAopProxy.java:243) ~[spring-aop-5.3.3.jar:5.3.3]

[marzelwidmer]

I update my Sample with the Code.. https://github.com/marzelwidmer/hateoas-demo/blob/750bed61f04b8ff8a370141eb3e383db[…]/main/kotlin/ch/keepcalm/hateoas/customer/CustomerController.kt

[marzelwidmer]

Is there maybe maven plugin missing….

[kqr]

try add dependency on

<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

[marzelwidmer]

Thanks .. same issues. still

[kqr]

and without hateoas it works as expected?

[marzelwidmer]

also with HATEOAS I only have a problem when I try with the Affordance links.andAffordance(afford<Any> { })

[marzelwidmer]

I am not sure maybe my (the issue) is about the null checks….. when I add the GET function (method) I don’t get any exception

[marzelwidmer]

but I also try to add a (in the sample) customer object or I miss something in the POST but I don’t get it…

[marzelwidmer]

image.png

[marzelwidmer]

now I try it from the Spring manual … <https://docs.spring.io/spring-hateoas/docs/1.1.0.RELEASE/reference/html/#server.affordances.api>

[marzelwidmer]

I think I get it now 🙂

[marzelwidmer]

I change the POST with a return value.

[marzelwidmer]

🙂 maybe I was too fast 😞

[kqr]

👍

[marzelwidmer]

I think I use the KotlinDSL wrong ..

val create: Affordance = afford<Any> {
            methodOn(CustomerController::class.java).add(customer = Customer(firstName = "", lastName = ""))
        }

[marzelwidmer]

with the following code I get again exception

[marzelwidmer]

The Type have to be like afford<CustomerController>

val create: Affordance = afford<CustomerController> {
            methodOn(CustomerController::class.java).add(customer = Customer(firstName = "", lastName = ""))
        }

[marzelwidmer]

Thanks for the support… 🙂