Use jackson annotation JsonUnwrapped on a field with name different from its getter

Question

I have a class like:

class Car {
    private Engine myEngine;

    @JsonProperty("color")
    private String myColor;  

    @JsonProperty("maxspeed")
    private int myMaxspeed;

    @JsonGetter("color")
    public String getColor()
    {
        return myColor;
    }

    @JsonGetter("maxspeed")
    public String getMaxspeed()
    {
        return myMaxspeed;
    }

    public Engine getEngine()
    {
        return myEngine;
    }
}

and Engine class like

class Engine {
    @JsonProperty("fueltype")
    private String myFueltype;

    @JsonProperty("enginetype")
    private String myEnginetype;

    @JsonGetter("fueltype")
    public String getFueltype()
    {
        return myFueltype;
    }

    @JsonGetter("enginetype")
    public String getEnginetype()
    {
        return myEnginetype;
    }
}

I want to convert the Car object to JSON using Jackson with structure like

'car': {
   'color': 'red',
   'maxspeed': '200',
   'fueltype': 'diesel',
   'enginetype': 'four-stroke'
 }

I have tried answer provided in this but it doesn't work for me as field names are different then getter

I know I can use @JsonUnwrapped on engine if field name was engine. But how to do in this situation.

score 12 · Accepted Answer · answered Sep 08 '17 at 08:47

12

provide @JsonUnwrapped and @JsonProperty together:

@JsonUnwrapped
@JsonProperty("engine")
private Engine myEngine;

answered Sep 08 '17 at 08:47

Sachin Gupta

7,805
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score 0 · Answer 2 · answered Sep 08 '17 at 06:11

0

You shall use the @JsonUnwrapped as follows in the Car class for the desired JSON object:

class Car {

    @JsonUnwrapped
    private Engine myEngine;

    @JsonProperty("color")
    private String myColor;  

    @JsonProperty("maxspeed")
    private int myMaxspeed;
    ...

answered Sep 08 '17 at 06:11

Naman

27,789
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1

Thanks for quick answer but this is not working. It creates a engine object in json – learner Sep 08 '17 at 06:16

score 0 · Answer 3 · answered Sep 08 '17 at 09:04

I think the best solution here would be to use @JsonValue annotation over the myEngineType attribute in your Engine class, it will only serialize this attribute instead of the whole Engine object.

So your code would be like this:

class Engine {

    @JsonProperty("fueltype")
    private String myFueltype;

    @JsonValue
    @JsonProperty("enginetype")
    private String myEnginetype;

}

You can take a look at this answer for more details.

Use jackson annotation JsonUnwrapped on a field with name different from its getter

3 Answers3

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