Jackson 2.0 with Spring 3.1

Question

Is Spring MVC 3.1 compatible with Jackson 2.0? Will Spring MVC's automatic detection of Jackson on the classpath, and delegation to Jackson for requests with a JSON content-type still work?

Solution 1

Support for Jackson 2 has been added in Spring 3.2, and has also backported to Spring 3.1.2 (SPR-9507)

Solution 2

Keith Donald (of spring source) tweeted the following a while back.

Spring MVC support for Jackson 2; also works with Jackson's native "pretty print" feature https://gist.github.com/2423129

I haven't tried the MappingJackson2HttpMessageConverter found in the gist above but it would surprise me if it did not work.

Solution 3

Since Spring 3.1.2 you simply have to add jackson-databind jar to your classpath.

In Maven you can configure it like this:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>${jackson.version}</version>
</dependency>

The rest of the magic will be done by spring automatically.

See: http://norrisshelton.wordpress.com/2012/07/15/spring-3-mvc-with-json-via-jackson-2-0/

Solution 4

For Spring 3.1.2 and Jackson 2 -

• As outlined above, the automatic support JustWorks™

• but configuration doesn't, as most of the web is littered with pre Spring3/Jackson2 configuration mechanisms

So for posterity, I'll list out a hack(? or is this the official way) to configure the Jackson converter. In this particular case, I am configuring the converter to return dates in the ISO-8601 format:

package foo.bar.JacksonConfig;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.stereotype.Component;

@Component
public class JacksonConfig implements BeanPostProcessor {

    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }

    public Object postProcessAfterInitialization(Object bean, String beanName)
            throws BeansException {
        if (bean instanceof MappingJackson2HttpMessageConverter) {
            MappingJackson2HttpMessageConverter jsonConverter =
                    (MappingJackson2HttpMessageConverter) bean;
            ObjectMapper objectMapper = jsonConverter.getObjectMapper();
            objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
            jsonConverter.setObjectMapper(objectMapper);
        }
        return bean;
    }
}

Solution 5

To be clear, Spring 3.1 doesn't have native support for Jackson 2. It's in Spring 3.2

View more solutions

Comments

[nicholas.hauschild]

Why wouldn't they? Have you tried and observed that it doesn't work?

[danny.lesnik]

stackoverflow.com/questions/10085088/…

[Manav]

You'll need to change your pom.xml if you're migrating from 1.x (Step 1: Update Maven / JAR dependencies from cowtowncoder.com/blog/archives/2012/04/entry_469.html is all you need for the builtin support to latch on)

[Roy Truelove]

I'm sure that this is not the official way but it's very clever!

[emas]

Yes it works, they added the MappingJackson2HttpMessageConverter class that is meant to be used instead of the "old" MappingJacksonHttpMessageConverter

[Ryan Walls]

The "official" method of configuring this is described here: wallsofchange.wordpress.com/2013/02/02/…. The only difference for Jackson 2 is that you have to use MappingJackson2HttpMessageConverter instead of MappingJacksonHttpMessageConverter and SerializationFeature.WRITE_DATES_AS_TIMESTAMPS instead of SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS.

[Adam]

Both of these did the trick for me.