Here is an example of using the FieldProperty class from the com.fasterxml.jackson.databind package in the Jackson library to handle a field property:

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;
import com.fasterxml.jackson.databind.introspect.AnnotatedField;
import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
import com.fasterxml.jackson.databind.introspect.FieldProperty;
import com.fasterxml.jackson.databind.introspect.POJOPropertyBuilder;

public class FieldPropertyExample {
    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);

        MyObject obj = new MyObject();
        obj.setMyField("myValue");

        String json = mapper.writeValueAsString(obj);
        System.out.println(json);

        MyObject obj2 = mapper.readValue(json, MyObject.class);
        System.out.println(obj2.getMyField());
    }
}

class MyObject {
    @JsonProperty("my_field")
    private String myField;

    public String getMyField() {
        return myField;
    }

    public void setMyField(String myField) {
        this.myField = myField;
    }
}

class MyPOJOPropertyBuilder extends POJOPropertyBuilder {
    @Override
    protected BeanPropertyDefinition _construct(AnnotatedField field) {
        BeanPropertyDefinition def = super._construct(field);
        if (def instanceof FieldProperty) {
            FieldProperty fieldProp = (FieldProperty) def;
            fieldProp.getField().setAccessible(true);
        }
        return def;
    }
}

This code defines a simple MyObject class with a field myField, and the @JsonProperty annotation is used to set a custom property name for the field. The ObjectMapper is configured to use the PropertyNamingStrategy.SNAKE_CASE strategy to convert the field name to snake_case.

The MyPOJOPropertyBuilder overrides the _construct method of POJOPropertyBuilder to make the field accessible using setAccessible(true) method.

The ObjectMapper is then used to serialize and deserialize the MyObject instances. The FieldProperty class is used to handle the field property and its related configuration.