RestEasy: org.codehaus.jackson.map.JsonMappingException: Unable to deserialize java.util.ArrayList instance from START_OBJECT (..) token
I have a resting endpoint that returns List<VariablePresentation>
. I am trying to test this endpoint breakpoint as
@Test
public void testGetAllVariablesWithoutQueryParamPass() throws Exception {
final ClientRequest clientCreateRequest = new ClientRequest("http://localhost:9090/variables");
final MultivaluedMap<String, String> formParameters = clientCreateRequest.getFormParameters();
final String name = "testGetAllVariablesWithoutQueryParamPass";
formParameters.putSingle("name", name);
formParameters.putSingle("type", "String");
formParameters.putSingle("units", "units");
formParameters.putSingle("description", "description");
formParameters.putSingle("core", "true");
final GenericType<List<VariablePresentation>> typeToken = new GenericType<List<VariablePresentation>>() {
};
final ClientResponse<List<VariablePresentation>> clientCreateResponse = clientCreateRequest.post(typeToken);
assertEquals(201, clientCreateResponse.getStatus());
final List<VariablePresentation> variables = clientCreateResponse.getEntity();
assertNotNull(variables);
assertEquals(1, variables.size());
}
This test fails with an error saying
org.codehaus.jackson.map.JsonMappingException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token(..)
How can I fix this problem?
+3
source to share
1 answer
This looks like a Jackson bug where he expects to parse an array (which starts with "["), but he encounters an initial token for the object ('{'). From looking at your code, I am assuming it is trying to deserialize JSON into your list, but it is getting JSON for an object.
What does your REST endpoint return JSON? It should look like this.
[
{
// JSON for VariablePresentation value 0
"field0": <some-value>
<etc...>
},
<etc...>
]
+6
source to share