CODEWITHSUNDEEP
javajsonjackson
hvgotcodes
hvgotcodes

Reputation: 120268

Can Jackson deal with intermediate relationships

Let's say I have a parent child relationship. My Parent json looks like

{
   childrens: [...]
}

Let's say the model I want to (de)serialize to/from has an intermediate object between the parent and children. 

class Parent {
   Intermediate intermediate
}

class Intermediate {
   Child[] children;
}

Can I configure Jackson to create that intermediate object when deserializing the json into the model, and similarly skip the intermediate object when serializing back to json?

Upvotes: 0

Views: 313

Answers (1)

rmlan
rmlan

Reputation: 4657

You can use the @JsonUnwrappedannotation for this case. Here is an example with a similar structure to your post

Parent.java

import com.fasterxml.jackson.annotation.JsonUnwrapped;

public class Parent {

    @JsonUnwrapped
    private Intermediate intermediate;

    public Intermediate getIntermediate() {
        return intermediate;
    }

    public void setIntermediate(Intermediate intermediate) {
        this.intermediate = intermediate;
    }
}

Intermediate.java

public class Intermediate {
    private Child[] children;

    public Child[] getChildren() {
        return children;
    }

    public void setChildren(Child[] children) {
        this.children = children;
    }
}

Child.java

public class Child {
    private String name;
    private Integer age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

Example document

{
  "children": [
    {
      "name": "Foo",
      "age": 20
    },
    {
      "name": "Bar",
      "age": 22
    }
  ]  
}

Test Driver

ObjectMapper mapper = new ObjectMapper();
Parent parent = mapper.readValue(json, Parent.class);

for (Child child : parent.getIntermediate().getChildren()) {
    System.out.println("Child: " + child.getName() + " is " + child.getAge() + " years old.");
}

Which produces the following output:

Child: Foo is 20 years old.
Child: Bar is 22 years old.

Upvotes: 1

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