Unable to send the post request in spring cloud contract

Question

I am trying to send a post request via RestAssuredMockMvc.standaloneSetup() and I am getting the below error for the request. I have my contracts in Groovy file with request and response code. I am getting the 400 response below the following exception.

org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not construct instance of com.organisation.online.myService.common.model.Payload, problem: abstract types either need to be mapped to concrete types, have custom deserializer, or be instantiated with additional type information
at [Source: java.io.PushbackInputStream@6064493f; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of com.organisation.onlinebank.myService.common.model.Payload, problem: abstract types either need to be mapped to concrete types, have custom deserializer, or be instantiated with additional type information
at [Source: java.io.PushbackInputStream@6064493f; line: 1, column: 1]
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:240)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:225)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:201)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:150)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:128)
at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121)
at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:160)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:129)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:595)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:65)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:167)
at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:134)
at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:155)
at com.jayway.restassured.module.mockmvc.internal.MockMvcRequestSenderImpl.performRequest(MockMvcRequestSenderImpl.java:174)
at com.jayway.restassured.module.mockmvc.internal.MockMvcRequestSenderImpl.sendRequest(MockMvcRequestSenderImpl.java:404)
at com.jayway.restassured.module.mockmvc.internal.MockMvcRequestSenderImpl.post(MockMvcRequestSenderImpl.java:590)
at com.jayway.restassured.module.mockmvc.internal.MockMvcRequestSenderImpl.post(MockMvcRequestSenderImpl.java:79)
at com.jayway.restassured.module.mockmvc.internal.MockMvcRequestSpecificationImpl.post(MockMvcRequestSpecificationImpl.java:752)
at com.jayway.restassured.module.mockmvc.internal.MockMvcRequestSpecificationImpl.post(MockMvcRequestSpecificationImpl.java:66)
at org.springframework.cloud.contract.verifier.tests.ContractVerifierTest.validate_should_Create_post_Request(ContractVerifierTest.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

---

At the end of above exception.. here is the following junit assertion

expected:<[2]00> but was:<[4]00>
Expected :200
Actual   :400
<Click to see difference>

org.junit.ComparisonFailure: expected:<[2]00> but was:<[4]00>
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at org.springframework.cloud.contract.verifier.tests.ContractVerifierTest.validate_should_Create_post_Request(ContractVerifierTest.java:28)

The actual payload which is sent inside the request is an interface and I know that could be the problem in creating the request payload. Other than that, I don't know how to deal with this error. Any clues will be appreciated.

Answer 1

I have used spring framework's MappingJackson2HttpMessageConverter to deserialize the object. Here is my implementation code.

Write a static class with the below method.

public class MappingJacksonFactory {

public static MappingJackson2HttpMessageConverter create() {
    MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
    ObjectMapper objectMapper = converter.getObjectMapper();
    objectMapper.enable(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS);
    objectMapper.enable(SerializationFeature.WRITE_BIGDECIMAL_AS_PLAIN);
    SimpleModule module = new TypeModuleFactory();
    objectMapper.registerModule(module);
    return converter;
   }

}

Use the above code inside setMessageConverter() method converters.

RestAssuredMockMvc.standaloneSetup(MockMvcBuilders.standaloneSetup(new yourController()))
            .setMessageConverters(MappingJacksonFactory.create());