CODEWITHSUNDEEP
javajsonserializationjackson
Bohemian
Bohemian

Reputation: 425073

Output a field to multiple json fields

Is there a way using, Jackson annotations, to have a have given field serialised to 2 json fields.

Like the reverse of @JsonAlias which deserialises multiple json field to the one field.

Eg

class Foo {
    @SomeAnnotation("field2")
    String field1;
}

serialising as:

{
    "field1" : "xyz",
    "field2" : "xyz"
}

Is there a something like @SomeAnnotation?

——

Note: This is not a “should” I do this (it’s an imposed requirement), it’s a “how” I do this (elegantly).

Upvotes: 4

Views: 1616

Answers (1)

ernest_k
ernest_k

Reputation: 45319

A simple solution to this may be to just add two getters for field1:

class Foo {
    private String field1 = "blah";

    public String getField1() {
        return field1;
    }

    public String getField2() {
        return field1;
    }
}

Jackson will create a field for each getter, following the javabeans naming convention:

{"field1":"blah","field2":"blah"}

An alternative to this may be @com.fasterxml.jackson.annotation.JsonAnyGetter, which can afford you even more flexibility:

class Foo {
    private String field1 = "blah";

    public String getField1() {
        return field1;
    }

    @JsonAnyGetter
    public Map<String, Object> getAny() {
        Map<String, Object> m = new HashMap<>();
        m.put("field2", this.field1);
        m.put("field3", this.field1.toUpperCase());

        return m;
    }
}

Producing:

{"field1":"blah","field3":"BLAH","field2":"blah"}

Upvotes: 4

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