From 2186f6412677edef05a2700775b4cbbf6ed3b3b6 Mon Sep 17 00:00:00 2001
From: slavisa-baeldung <slavisa.baeldung@gmail.com>
Date: Sun, 20 Nov 2016 22:35:17 +0100
Subject: [PATCH] BAEL-376 - java generics code

---
 .../java/com/baeldung/generics/Generics.java  | 31 ++++-----
 .../com/baeldung/generics/GenericsTest.java   | 69 +++++++++----------
 2 files changed, 47 insertions(+), 53 deletions(-)

diff --git a/core-java/src/main/java/com/baeldung/generics/Generics.java b/core-java/src/main/java/com/baeldung/generics/Generics.java
index ce1325687f..69c7baddd3 100644
--- a/core-java/src/main/java/com/baeldung/generics/Generics.java
+++ b/core-java/src/main/java/com/baeldung/generics/Generics.java
@@ -1,24 +1,23 @@
+package com.baeldung.generics;
+
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public class Generics {
 
-	// definition of a generic method
-	public static <T> List<T> fromArrayToList(T[] a) {
-		List<T> list = new ArrayList<>();
-		for (T t : a) {
-			list.add(t);
-		}
-		return list;
-	}
+    // definition of a generic method
+    public static <T> List<T> fromArrayToList(T[] a) {
+        List<T> list = new ArrayList<>();
+        Arrays.stream(a).forEach(list::add);
+        return list;
+    }
 
-	// example of a generic method that has Number as an upper bound for T
-	public static <T extends Number> List<T> fromArrayToListWithUpperBound(T[] a) {
-		List<T> list = new ArrayList<>();
-		for (T t : a) {
-			list.add(t);
-		}
-		return list;
-	}
+    // example of a generic method that has Number as an upper bound for T
+    public static <T extends Number> List<T> fromArrayToListWithUpperBound(T[] a) {
+        List<T> list = new ArrayList<>();
+        Arrays.stream(a).forEach(list::add);
+        return list;
+    }
 
 }
diff --git a/core-java/src/test/java/com/baeldung/generics/GenericsTest.java b/core-java/src/test/java/com/baeldung/generics/GenericsTest.java
index 7778f8ea81..9eb459ccb5 100644
--- a/core-java/src/test/java/com/baeldung/generics/GenericsTest.java
+++ b/core-java/src/test/java/com/baeldung/generics/GenericsTest.java
@@ -1,46 +1,41 @@
-import java.util.Iterator;
-import java.util.List;
+package com.baeldung.generics;
 
 import org.junit.Test;
 
+import java.util.List;
+
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.MatcherAssert.assertThat;
+
 public class GenericsTest {
 
-	// testing the generic method with Integer
-	@Test
-	public void fromArrayToListIntTest() {
-		Integer[] intArray = { 1, 2, 3, 4, 5 };
-		List<Integer> list = Generics.fromArrayToList(intArray);
-		Iterator<Integer> iterator;
-		iterator = list.iterator();
-		while (iterator.hasNext()) {
-			System.out.println(iterator.next());
-		}
-	}
+    // testing the generic method with Integer
+    @Test
+    public void givenArrayOfIntegers_thanListOfIntegersReturnedOK() {
+        Integer[] intArray = {1, 2, 3, 4, 5};
+        List<Integer> list = Generics.fromArrayToList(intArray);
 
-	// testing the generic method with String
-	@Test
-	public void fromArrayToListStringTest() {
-		String[] stringArray = { "hello1", "hello2", "hello3", "hello4", "hello5" };
-		List<String> list = Generics.fromArrayToList(stringArray);
-		Iterator<String> iterator;
-		iterator = list.iterator();
-		while (iterator.hasNext()) {
-			System.out.println(iterator.next());
-		}
-	}
+        assertThat(list, hasItems(intArray));
+    }
 
-	// testing the generic method with Number as upper bound with Integer
-	// if we test fromArrayToListWithUpperBound with any type that doesn't
-	// extend Number it will fail to compile
-	@Test
-	public void fromArrayToListUpperboundIntTest() {
-		Integer[] intArray = { 1, 2, 3, 4, 5 };
-		List<Integer> list = Generics.fromArrayToListWithUpperBound(intArray);
-		Iterator<Integer> iterator;
-		iterator = list.iterator();
-		while (iterator.hasNext()) {
-			System.out.println(iterator.next());
-		}
-	}
+    // testing the generic method with String
+    @Test
+    public void givenArrayOfStrings_thanListOfStringsReturnedOK() {
+        String[] stringArray = {"hello1", "hello2", "hello3", "hello4", "hello5"};
+        List<String> list = Generics.fromArrayToList(stringArray);
+
+        assertThat(list, hasItems(stringArray));
+    }
+
+    // testing the generic method with Number as upper bound with Integer
+    // if we test fromArrayToListWithUpperBound with any type that doesn't
+    // extend Number it will fail to compile
+    @Test
+    public void givenArrayOfIntegersAndNumberUpperBound_thanListOfIntegersReturnedOK() {
+        Integer[] intArray = {1, 2, 3, 4, 5};
+        List<Integer> list = Generics.fromArrayToListWithUpperBound(intArray);
+
+        assertThat(list, hasItems(intArray));
+    }
 
 }