[FIXED] Consuming JSON that may return a different data

Issue

I'd like to write some java code using spring boot to consume JSON data from a specific endpoint. However with each request the response may return different data fields as such.

{"success":true,"terms":"https:\/\/coinlayer.com\/terms","privacy":"https:\/\/coinlayer.com\/privacy","timestamp":1645616586,"target":"USD","rates":{"BTC":39049.424242}}

{"success":true,"terms":"https:\/\/coinlayer.com\/terms","privacy":"https:\/\/coinlayer.com\/privacy","timestamp":1645626666,"target":"USD","rates":{"BTC":39061.184046,"ETH":2726.545731}}

{"success":true,"terms":"https:\/\/coinlayer.com\/terms","privacy":"https:\/\/coinlayer.com\/privacy","timestamp":1645626966,"target":"USD","rates":{"ADA":0.939301,"BTC":39006.990707,"ETH":2720.502765}}

and so on.

Below is my current code which deals with the first case presented. I could write another Rates.java to cater for the second case and so on but I'm looking to have one Rates.java file which deals with all possible cases.

LiveData.java

package com.example.consumingrest;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

@JsonIgnoreProperties(ignoreUnknown = true)
public class LiveData {

    private Boolean success;
    private String terms;
    private String privacy;
    private Long timestamp;
    private String target;
    private Rates rates;

    public LiveData() {
    }

    public Boolean getSuccess() {
        return success;
    }

    public void setSuccess(Boolean success) {
        this.success = success;
    }

    public String getTerms() {
        return terms;
    }

    public void setTerms(String terms) {
        this.terms = terms;
    }

    public String getPrivacy() {
        return privacy;
    }

    public void setPrivacy(String privacy) {
        this.privacy = privacy;
    }

    public Long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Long timestamp) {
        this.timestamp = timestamp;
    }

    public String getTarget() {
        return target;
    }

    public void setTarget(String target) {
        this.target = target;
    }

    public Rates getRates() {
        return rates;
    }

    public void setValue(Rates rates) {
        this.rates = rates;
    }

    @Override
    public String toString() {
        return "LiveData{" +
                "success='" + success + '\'' +
                "terms='" + terms + '\'' +
                "privacy='" + privacy + '\'' +
                "timestamp='" + timestamp + '\'' +
                "target='" + target + '\'' +
                "rates=" + rates +
                '}';
    }
}

Rates.java

package com.example.consumingrest;
import java.math.BigDecimal;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;

@JsonIgnoreProperties(ignoreUnknown = true)
public class Rates {
    @JsonProperty(value = "BTC")
    private BigDecimal btc;

    public Rates() {
    }

    public BigDecimal getBTC() {
        return this.btc;
    }

    public void setId(BigDecimal btc) {
        this.btc = btc;
    }


    @Override
    public String toString() {
        return "{" +
                "BTC='" + btc + '\''+
                '}';
    }
}

ConsumingRest.java (main)

package com.example.consumingrest;

import java.time.LocalDate;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
public class ConsumingRestApplication {

    private static final Logger log = LoggerFactory.getLogger(ConsumingRestApplication.class);

    public static void main(String[] args) {
        SpringApplication.run(ConsumingRestApplication.class, args);
    }

    @Bean
    public RestTemplate restTemplate(RestTemplateBuilder builder) {
        return builder.build();
    }

    @Bean
    public CommandLineRunner run(RestTemplate restTemplate) throws Exception {
        return args -> {
            LiveData liveData = restTemplate.getForObject(
                    "http://api.coinlayer.com/api/live?access_key=121a4df8b95fd5be872da3bad101cd73&target=EUR&symbols=BTC", LiveData.class);
            log.info(liveData.toString());
        };
    }
}

Solution

As mentioned in the comments, seems you want a map containing the rates:

@JsonIgnoreProperties(ignoreUnknown = true)
public class LiveData {
    ...
    private Map<String, BigDecimal> rates;

See Mapping a Dynamic JSON Object

Answered By - M A
Answer Checked By - David Marino (JavaFixing Volunteer)