f-hw-jv-stream-github-practice

src/main/java/practice/CandidateValidator.java

@@ -1,5 +1,32 @@
 package practice;
 
-public class CandidateValidator {
-    //write your code here
+import java.util.function.Predicate;
+import model.Candidate;
+
+public class CandidateValidator implements Predicate<Candidate> {
+    private static final int FIRST_INDEX_START = 0;
+    private static final int LAST_INDEX_END = 1;
+    private static final int MIN_AGE_FOR_CANDIDATE = 35;
+    private static final int MIN_PERIOD_IN_UKRAINE = 10;
+    private static final String NATIONALITY_FOR_CANDIDATE = "Ukrainian";
+
+    @Override
+    public boolean test(Candidate candidate) {
+        return candidate.getAge() >= MIN_AGE_FOR_CANDIDATE
+                && candidate.isAllowedToVote()
+                && candidate.getNationality().equals(NATIONALITY_FOR_CANDIDATE)
+                && getLivePeriodInUkraine(candidate.getPeriodsInUkr()) >= MIN_PERIOD_IN_UKRAINE;
+    }
+
+    public static int getLivePeriodInUkraine(String periodsInUkr) {
+        String[] split = periodsInUkr.split("-");
+        int period = 0;
+        try {
+            period = Integer.parseInt(split[LAST_INDEX_END])
+                    - Integer.parseInt(split[FIRST_INDEX_START]);
+        } catch (NumberFormatException e) {
+            System.out.println("String does not contain a parsable integer");
+        }
+        return period;
+    }
 }

src/main/java/practice/StreamPractice.java

@@ -1,11 +1,18 @@
 package practice;
 
-import java.util.Collections;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 import model.Candidate;
+import model.Cat;
 import model.Person;
 
 public class StreamPractice {
+    private final CandidateValidator candidateValidator = new CandidateValidator();
+
     /**
      * Given list of strings where each element contains 1+ numbers:
      * input = {"5,30,100", "0,22,7", ...}
@@ -14,7 +21,13 @@ public class StreamPractice {
      * "Can't get min value from list: < Here is our input 'numbers' >"
      */
     public int findMinEvenNumber(List<String> numbers) {
-        return 0;
+        return numbers.stream()
+                .flatMap(s -> Arrays.stream(s.split(",")))
+                .mapToInt(Integer::parseInt)
+                .filter(n -> n % 2 == 0)
+                .min()
+                .orElseThrow(() -> new RuntimeException(
+                        "Can't get min value from list:" + numbers));
     }
 
     /**
@@ -23,7 +36,11 @@ public int findMinEvenNumber(List<String> numbers) {
      * But before that subtract 1 from each element on an odd position (having the odd index).
      */
     public Double getOddNumsAverage(List<Integer> numbers) {
-        return 0D;
+        return IntStream.range(0, numbers.size())
+                .map(index -> index % 2 != 0 ? numbers.get(index) - 1 : numbers.get(index))
+                .filter(n -> n % 2 != 0)
+                .average()
+                .orElseThrow(NoSuchElementException::new);
     }
 
     /**
@@ -35,7 +52,10 @@ public Double getOddNumsAverage(List<Integer> numbers) {
      * Example: select men who can be recruited to army (from 18 to 27 years old inclusively).
      */
     public List<Person> selectMenByAge(List<Person> peopleList, int fromAge, int toAge) {
-        return Collections.emptyList();
+        return peopleList.stream()
+                .filter(p -> p.getSex().equals(Person.Sex.MAN)
+                        && p.getAge() >= fromAge && p.getAge() <= toAge)
+                .collect(Collectors.toList());
     }
 
     /**
@@ -50,7 +70,14 @@ public List<Person> selectMenByAge(List<Person> peopleList, int fromAge, int toA
      */
     public List<Person> getWorkablePeople(int fromAge, int femaleToAge,
                                           int maleToAge, List<Person> peopleList) {
-        return Collections.emptyList();
+        return peopleList.stream()
+                .filter(person -> ((person.getSex().equals(Person.Sex.MAN)
+                        && person.getAge() > fromAge
+                        && person.getAge() <= maleToAge)
+                        || (person.getSex().equals(Person.Sex.WOMAN)
+                        && person.getAge() >= fromAge
+                        && person.getAge() <= femaleToAge)))
+                .collect(Collectors.toList());
     }
 
     /**
@@ -59,7 +86,13 @@ public List<Person> getWorkablePeople(int fromAge, int femaleToAge,
      * return the names of all cats whose owners are women from `femaleAge` years old inclusively.
      */
     public List<String> getCatsNames(List<Person> peopleList, int femaleAge) {
-        return Collections.emptyList();
+        return peopleList.stream()
+                .filter(person -> person.getSex().equals(Person.Sex.WOMAN)
+                        && person.getAge() >= femaleAge)
+                .map(Person::getCats)
+                .flatMap(Collection::stream)
+                .map(Cat::getName)
+                .collect(Collectors.toList());
     }
 
     /**
@@ -69,12 +102,16 @@ public List<String> getCatsNames(List<Person> peopleList, int femaleAge) {
      * names sorted alphabetically.
      * The requirements are: person should be older than 35 years, should be allowed to vote,
      * have nationality - 'Ukrainian'
-     * and live in Ukraine for 10 years. For the last requirement use field periodsInUkr,
+     * and live in Ukraine for 10 years. For the last requirement use field Ukrainian',
      * which has following view: "2002-2015"
      * We want to reuse our validation in future, so let's write our own impl of Predicate
      * parametrized with Candidate in CandidateValidator.
      */
     public List<String> validateCandidates(List<Candidate> candidates) {
-        return Collections.emptyList();
+        return candidates.stream()
+                .filter(candidateValidator)
+                .map(Candidate::getName)
+                .sorted()
+                .toList();
     }
 }