RestEasy:org.codehaus.jackson.map.JsonMappingException:无法从START_OBJECT标记(..)中反序列化java.util.ArrayList的实例

时间:2013-02-08 15:36:06

标签: java unit-testing jackson resteasy

我有一个返回List<VariablePresentation>的休息端点。我试图将此休止端点测试为

    @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());

    }

此测试失败并显示错误

org.codehaus.jackson.map.JsonMappingException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token(..)

如何解决此问题?

1 个答案:

答案 0 :(得分:6)

这看起来像是一个Jackson错误,它期望解析一个数组(以'['开头),但它遇到一个对象的开始标记('{')。从查看你的代码,我猜它正在尝试将JSON反序列化到你的List中,但是它获得了一个对象的JSON。

您的REST端点返回的JSON是什么样的?应该看起来像这样

[
    {
        // JSON for VariablePresentation value 0
        "field0": <some-value>
        <etc...>
    },
    <etc...>
]