Spring Boot 1.4 Customize Internal Jackson Deserialization

Question

I am using spring.jackson.deserialization.FAIL_ON_UNKNOWN_PROPERTIES=true in the application.properties to make deserialization fail on unknown properties but its not working.

I even tried using :

@Bean
ObjectMapper objectMapper() {
  return Jackson2ObjectMapperBuilder
        .json()
        .featuresToEnable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
        .build();
}

But this also didn't work. What am I missing?

Can you post your code & the data which objects you are trying to deserialize? — Vasu, Mar 18 '17 at 12:36
Does it work if you define `Jackson2ObjectMapperBuilder` as in this question: https://stackoverflow.com/questions/34545997/put-and-post-fail-on-unknown-properties-spring-different-behavior ? — Infinity, Mar 18 '17 at 13:06
@Infinity Thanks for quick reply. I tried that also but didn't work It's a plain project with spring-boot web dependency and a PUT request method to update user (right i'm not hitting database,i'm just logging update request to test method ) and a Plain User Model without any additional annotations. — Kiba, Mar 18 '17 at 13:20
@Infinity It's working now, i cleared the m2 cache and rebuild it, maybe it was a version issue. Thanks for your quick replies. I'll check later what was causing it. — Kiba, Mar 18 '17 at 17:40

score 12 · Answer 1 · edited Mar 18 '17 at 17:01

12

With Spring boot, by default, unknown properties are ignored during deserialization. In order not to ignore these properties, you can :

Add spring.jackson.deserialization.FAIL_ON_UNKNOWN_PROPERTIES=true in the application.properties

Use this bean :

@Bean
public ObjectMapper objectMapper() {
    return Jackson2ObjectMapperBuilder
    .json()
    .featuresToEnable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
    .build();
}

Use this bean :

@Bean 
public Jackson2ObjectMapperBuilder objectMapperBuilder(){
    Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
    builder.failOnUnknownProperties(true);
    return builder;
}

I have tested these solutions and it works so there is another problem in your code. Please, can you post your code as ask by javaguy?

edited Mar 18 '17 at 17:01

Chacko

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answered Mar 18 '17 at 15:35

Sébastien Temprado

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Thanks for quick reply. It's working now, i cleared the m2 cache and rebuild it, maybe it was a version issue. I'll check later what was causing it. I'm not able to mark both your and Fırat guy's reply as an answer. But thanks for quick reply :). – Kiba Mar 18 '17 at 17:45
This answer is more complete, it provides multiple solutions, and in my case (relying on Spring's auto-configuration) Spring was instantiating multiple `ObjectMapper`s and only one of them used the property that I set in `application.properties`. Utilizing the third option from this answer worked for me (although I had to add a `@Bean` for `MappingJackson2HttpMessageConverter` that utilized my custom `Jackson2ObjectMapperBuilder` for it to work). – Tim Klein Jan 03 '19 at 15:36
If the setting in the application.yaml does not have the desired effect, then check your code. You may have defined an object mapper somewhere. This overwrites the setting behavior by default! – Sma Ma Nov 22 '22 at 11:24

Fırat Küçük · Accepted Answer · 2017-03-18T16:08:02.137

FAIL_ON_UNKNOWN_PROPERTIES option is true by default according to Jackson Documentation.

If you want to disable this setting you may add this option to application.properties.

spring.jackson.deserialization.fail-on-unknown-properties = false

But in default settings it works as expected. So no need for any setting.

This is one file spring boot application:

@RestController
@SpringBootApplication
public class TestOptionApplication {

    public static void main(String[] args) {
        SpringApplication.run(TestOptionApplication.class, args);
    }

    @PostMapping("/test")
    public void formTest(@RequestBody final HelloForm form) {
    }

    public static class HelloForm {

        private String name;

        public String getName() { return name; }

        public void setName(final String name) { this.name = name; }
    }
}

This is the integration test for testing rejection on unknown properties.

@RunWith(SpringRunner.class)
@SpringBootTest
public class TestOptionApplicationTest {

    @Autowired
    private WebApplicationContext context;

    @Test
    public void testFailOnUnknownPropertiesOption() throws Exception {

        final String text = "{\"name\": \"test\", \"title\": \"test\"}";

        MockMvcBuilders
            .webAppContextSetup(this.context)
            .build()
            .perform(post("/test").contentType(MediaType.APPLICATION_JSON).content(text))
            .andExpect(status().isBadRequest());
    }
}

title property is not defined. So controller sends BadRequest.

Thanks for quick reply. It's working now, i cleared the m2 cache and rebuild it, maybe it was a version issue. I'll check later what was causing it. I'll mark this as an answer. — Kiba, Mar 18 '17 at 17:42
I tried but it workd with uppercase: spring.jackson.deserialization.FAIL_ON_UNKNOWN_PROPERTIES. — Erikson Murrugarra, Dec 10 '19 at 23:26

Spring Boot 1.4 Customize Internal Jackson Deserialization

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