BAEL-668 find min/max from a list/collection (#1134)

* BAEL-668 find min/max from a list/collection

* BAEL-668 using mapToInt instead of Compare

* BAEL-668 using direct assertion with the method call

core-java/src/test/java/com/baeldung/java8/Java8MaxMinTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.java8;
+
+import com.baeldung.java_8_features.Person;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class Java8MaxMinTest {
+
+    @Test
+    public void whenListIsOfIntegerThenMaxCanBeDoneUsingIntegerComparator() {
+        //given
+        final List<Integer> listOfIntegers = Arrays.asList(1, 2, 3, 4, 56, 7, 89, 10);
+        final Integer expectedResult = 89;
+
+        //then
+        assertEquals(expectedResult,
+          (Integer) listOfIntegers.stream().mapToInt(val -> val).max().getAsInt());
+    }
+
+    @Test
+    public void whenListIsOfPersonObjectThenMinCanBeDoneUsingCustomComparatorThroughLambda() {
+        //given
+        final Person alex = new Person("Alex", 23);
+        final Person john = new Person("John", 40);
+        final Person peter = new Person("Peter", 32);
+        final List<Person> people = Arrays.asList(alex, john, peter);
+
+        //then
+        assertEquals("Alex must be having min age", alex,
+          people.stream().min((o1, o2) -> o1.getAge().compareTo(o2.getAge())).get());
+    }
+
+}