BAEL-1986 List initialization in one line (#4696)

* list initializations in one line

* Enhance after review

* formatting and naming

* Formatting and renaming 2

core-java/src/test/java/com/baeldung/java/listInitialization/ListInitializationUnitTest.java

@@ -0,0 +1,73 @@
+package com.baeldung.java.listInitialization;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import lombok.extern.java.Log;
+
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+@Log
+public class ListInitializationUnitTest {
+
+    @Rule
+    public ExpectedException exception = ExpectedException.none();
+
+    @Test
+    public void givenAnonymousInnerClass_thenInitialiseList() {
+        List<String> cities = new ArrayList() {
+            // Inside declaration of the subclass
+
+            // You can have multiple initializer block
+            {
+                log.info("Inside the first initializer block.");
+            }
+
+            {
+                log.info("Inside the second initializer block.");
+                add("New York");
+                add("Rio");
+                add("Tokyo");
+            }
+        };
+
+        Assert.assertTrue(cities.contains("New York"));
+    }
+
+    @Test
+    public void givenArraysAsList_thenInitialiseList() {
+        List<String> list = Arrays.asList("foo", "bar");
+
+        Assert.assertTrue(list.contains("foo"));
+    }
+
+    @Test
+    public void givenArraysAsList_whenAdd_thenUnsupportedException() {
+        List<String> list = Arrays.asList("foo", "bar");
+
+        exception.expect(UnsupportedOperationException.class);
+        list.add("baz");
+    }
+
+    @Test
+    public void givenArrayAsList_whenCreated_thenShareReference() {
+        String[] array = { "foo", "bar" };
+        List<String> list = Arrays.asList(array);
+        array[0] = "baz";
+        Assert.assertEquals("baz", list.get(0));
+    }
+
+    @Test
+    public void givenStream_thenInitializeList() {
+        List<String> list = Stream.of("foo", "bar")
+            .collect(Collectors.toList());
+
+        Assert.assertTrue(list.contains("foo"));
+    }
+}