CODEWITHSUNDEEP
javajsonjacksonpojo
choom
choom

Reputation: 45

convert json string into POJO containing @key

I have a json string as shown below.

{
    "input_index": 0,
    "candidate_index": 0,
    "delivery_line_1": "5461 S Red Cliff Dr",
    "last_line": "Salt Lake City UT 84123-5955",
    "delivery_point_barcode": "841235955990"
}

I want to convert into POJO of class as shown below.

public class Candidate {

    @Key("input_index")
    private int inputIndex;

    @Key("candidate_index")
    private int candidateIndex;

    @Key("addressee")
    private String addressee;

    @Key("delivery_line_1")
    private String deliveryLine1;

    @Key("delivery_line_2")
    private String deliveryLine2;

    @Key("last_line")
    private String lastLine;

    @Key("delivery_point_barcode")
    private String deliveryPointBarcode;
}

I am trying to convert json to pojo using jackson as shown below.

ObjectMapper objectMapper = new ObjectMapper();

objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

Candidate candidate = objectMapper.readValue(jsonString,Candidate.class);

When I run the code I am getting all null values in pojo because jackson is looking for attribute name in the json string instead of name given in @key. How do tell Jackson to map values based on @Key?

I used @JsonProperty before and had no issue converting into pojo. The Candidate class is provided by third party and they are using @key(com.google.api.client.util.Key) annotation for attributes. So, I can't change the class.

Upvotes: 2

Views: 2283

Answers (2)

Ramachandran.A.G
Ramachandran.A.G

Reputation: 4948

Assuming you are not able to change the class , you can use GSON as well to convert it back to Candidate class. I am suggesting this only because you cannot change the annotation in the POJO class that you have. 

    Gson gson = new Gson();

    String jsonInString = "{\"input_index\": 0,\"candidate_index\": 0,\"delivery_line_1\": \"5461 S Red Cliff Dr\",\"last_line\": \"Salt Lake City UT 84123-5955\",\"delivery_point_barcode\": \"841235955990\"}";

    Candidate candidate = gson.fromJson(jsonInString, Candidate.class);

    System.out.println(candidate);

Although this is no replacement for the JACKSON Annotation and object mapper you have , using GSON you are covered pretty much in this case on the Source POJO provided

edit you can also use JacksonFactory as below

import com.google.api.client.json.jackson.JacksonFactory;

    Candidate candidate2 = new JacksonFactory().fromString(jsonInString, Candidate.class);

    System.out.println(candidate2);

Upvotes: 0

Ebrahim Pasbani
Ebrahim Pasbani

Reputation: 9406

Use this maven dep :

<dependency>
    <groupId>com.google.http-client</groupId>
    <artifactId>google-http-client-jackson</artifactId>
    <version>1.15.0-rc</version>
</dependency>

And convert like this :

Candidate candidate = JacksonFactory.getDefaultInstance().fromString(output,Candidate.class);

Upvotes: 1

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