Code Challenge

java_age_counting.java

/*
Java Age counting

In the Java file, write a program to perform a GET request on the route:

https://coderbyte.com/api/challenges/json/age-counting

Which contains a data key and the value is a string which contains items in the format:

key=STRING, age=INTEGER

Your goal is to count how many items exist that have an age equal to or greater than 50, and print this final value.


Example Input

{"data": "key=IAfpK, age=58, key=WNVdi, age=64, key=jp9zt, age=47"}

Example output

2
/*

import java.util.*; 
import java.io.*;
import java.net.*;
import java.util.stream.Collectors;

class Main {  
  private final static int MAX_AGE = 50;
  public static void main (String[] args) { 
    System.setProperty("http.agent", "Chrome");
    try { 
      AgeRepository ageRepository = new AgeRepository(null);
      var ageByKey = ageRepository.countAgeByKey();
      var ages = new ArrayList<>(ageByKey.aValue.values());

      var amountOfAgesHigherThanMaxAge = ages
        .stream()
        .filter(age -> age >= Main.MAX_AGE)
        .collect(Collectors.toList())
        .size();
      
      System.out.println(amountOfAgesHigherThanMaxAge);
    } catch (IOException malEx) {
      System.out.println(malEx);
    }
  }   
}

class AgeRepository {
  private URL url;
  public AgeRepository(URL url) throws MalformedURLException {
    this.url = url == null ? new URL("https://coderbyte.com/api/challenges/json/age-counting") : url;
  }

  public AgeByKey countAgeByKey() throws IOException {
      String response = new String();
      URLConnection connection = this.url.openConnection();
      InputStream inputStream = connection.getInputStream();
      BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
      for (String line; (line = reader.readLine()) != null;) {
        response += line;
      }

      String[] keyValueJsonTupleResponse = response.split(":");
      
      if (keyValueJsonTupleResponse.length < 2) {
        return new AgeByKey("");
      }

      return new AgeByKey(keyValueJsonTupleResponse[1]);
  }
}

final class AgeByKey {
  public final Map<String, Integer> aValue = new HashMap<String, Integer>();

  public AgeByKey(String value) {
    aValue.putAll(parseRawValue(value));
  }

  private Map<String, Integer> parseRawValue(String value) {
    String[] valueByAttributes = value.split(",");

    if (valueByAttributes.length == 0) {
      return new HashMap<String, Integer>();
    }

    var attributesTuple = new ArrayList<List<String>>();
    for (int i = 0; i < valueByAttributes.length - 2; i+=2) {
      attributesTuple.add(
        Arrays.asList(
          this.getValueFromKeyValueAttribution(valueByAttributes[i]),
          this.getValueFromKeyValueAttribution(valueByAttributes[i+1])
        )
      );
    }

    return attributesTuple.stream().collect(
      Collectors.toConcurrentMap(
        v -> v.get(0),
        v -> Integer.parseInt(v.get(1)),
        (v, v2) -> v2
      )
    );
  }
  
  // Key=Value format
  private String getValueFromKeyValueAttribution(String keyValueAttribution) {
    return keyValueAttribution.substring(keyValueAttribution.lastIndexOf("=") + 1);
  }
}