Jackson-databind: PropertyNamingStrategy.UPPER_CAMEL_CASE for a private attribute which name starts with more than one uppercase letter

[dotdet]

PropertyNamingStrategy.UPPER_CAMEL_CASE doesn't work as expected when a property name should start with more than one uppercase letter (e.g. BADNamingStrategy) and the corresponding attribute is _private_ (which means that the property name is derived from the getter method)

The following test demonstrates that issue.

package org.me.jackson;

import static org.hamcrest.MatcherAssert.*;
import static org.hamcrest.CoreMatchers.*;

import org.junit.Test;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;

public class JacksonUpperCaseSerializationTest {

    ObjectMapper om = new ObjectMapper()
            .setPropertyNamingStrategy(PropertyNamingStrategy.UPPER_CAMEL_CASE);

    public static class Entity {
        // expected property name: BADPublicName
        public boolean bADPublicName = true;

        // expected property name: BADPrivateName, actual: BadprivateName
        private boolean privatePropertyNameDoesntMatter = true;

        public boolean getBADPrivateName() {
            return privatePropertyNameDoesntMatter;
        }

        public void setBADPrivateName(boolean bADPrivateName) {
            this.privatePropertyNameDoesntMatter = bADPrivateName;
        }
    }

    @Test
    public void testSerialization() throws Exception {
        final String json = om.writeValueAsString(new Entity());
        assertThat(json, containsString("BADPublicName"));

        // this one fails: it contains BadprivateName instead
        assertThat(json, containsString("BADPrivateName"));
    }

    @Test
    public void testDeserialization() throws Exception {        
        final String json = "{\"BADPublicName\":false,\"BADPrivateName\":false}";

        // here it says that it has only (2 known properties: "BADPublicName", "BadprivateName"])
        final Entity entity = om.readValue(json, Entity.class); 

        assertThat(entity.bADPublicName, is(false));
        assertThat(entity.getBADPrivateName(), is(false));
    }

}

This is related to the version 2.8.9

[cowtowncoder]

I don't think private field should have any effect here since it is not associated with getter/setter name, as far as I can see. Those names must link for any association.

But other than that, code looks like it should work.

... and when I try it, tests pass for me.

[cowtowncoder]

Hmmh. Odd. Test passed with master (for 3.0.0-SNAPSHOT) but not with 2.9 branch, and likely also fails with 2.8.

[cowtowncoder]

Ahhh. This is actually due to one minor (usually) deviation Jackson has from Bean naming: if multiple leading letters are upper-case, Jackson lower-cases them all (by default), so "BADxxx" becomes "badxxx". But upper case strategy only upper-cases the first letter, leading to problem here.
This behavior can be changed by:

mapper.enable(MapperFeature.USE_STD_BEAN_NAMING)

which is disabled by default; doing this will solve the problem.
And 3.0.0 has this behavior as default (2.x does not just for backwards compatibility).

So, you need to enable this feature.