Mapping a dynamic json object field in Jackson?

Question

I have json objects in the following schema:

{
  name: \"foo\",
  timestamp: 1475840608763,
  payload:
  {
     foo: \"bar\"
  }
}

Here, th

Answer 1

Does this help?

import java.util.HashMap;
import java.util.Map;

import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;

public class Payload {

    private final Map other = new HashMap<>();

    @JsonAnyGetter
    public Map any() {
        return other;
    }

    @JsonAnySetter
    public void set(final String name, final Object value) {
        other.put(name, value);
    }

    public Map getOther() {
        return other;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = (prime * result) + ((other == null) ? 0 : other.hashCode());
        return result;
    }

    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof Payload)) {
            return false;
        }
        Payload other = (Payload) obj;
        if (this.other == null) {
            if (other.other != null) {
                return false;
            }
        } else if (!this.other.equals(other.other)) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "Payload [other=" + other + "]";
    }

}

Then this owning class

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

public class Outer {

    private final String name;
    private final long timestamp;

    private final Payload payload;

    @JsonCreator
    public Outer(@JsonProperty("name") final String name, @JsonProperty("timestamp") final long timestamp, @JsonProperty("payload") final Payload payload) {
        super();
        this.name = name;
        this.timestamp = timestamp;
        this.payload = payload;
    }

    public String getName() {
        return name;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public Payload getPayload() {
        return payload;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = (prime * result) + ((name == null) ? 0 : name.hashCode());
        result = (prime * result) + ((payload == null) ? 0 : payload.hashCode());
        result = (prime * result) + (int) (timestamp ^ (timestamp >>> 32));
        return result;
    }

    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof Outer)) {
            return false;
        }
        Outer other = (Outer) obj;
        if (name == null) {
            if (other.name != null) {
                return false;
            }
        } else if (!name.equals(other.name)) {
            return false;
        }
        if (payload == null) {
            if (other.payload != null) {
                return false;
            }
        } else if (!payload.equals(other.payload)) {
            return false;
        }
        if (timestamp != other.timestamp) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "Outer [name=" + name + ", timestamp=" + timestamp + ", payload=" + payload + "]";
    }

}

Then to test

public class Main {

    private static final ObjectMapper mapper = new ObjectMapper();

    public static void main(final String... args) throws JsonParseException, JsonMappingException, IOException {

        final Outer outer = mapper.readValue(new File("test.json"), Outer.class);

        System.out.println(outer);


    }

}

Gives console output of

Outer [name=foo, timestamp=1475840608763, payload=Payload [other={foo=bar}]]