added review changes

java-numbers/src/main/java/com/baeldung/casting/DoubleToInteger.java

@@ -1,42 +0,0 @@
-package com.baeldung.casting;
-
-public class DoubleToInteger {
-
-    static Double value = 99999.999;
-
-    public static void main(String[] args) {
-
-        System.out.println(usingIntValue(value));
-
-        System.out.println(usingMathRound(value));
-        System.out.println(usingMathCeil(value));
-
-        System.out.println(usingMathFloor(value));
-        System.out.println(usingMathAbs(value));
-    }
-
-    public static Integer usingIntValue(Double value) {
-        return value.intValue();
-    }
-
-    public static Integer usingMathRound(Double value) {
-        return (int) Math.round(value);
-    }
-
-    public static Integer usingMathCeil(Double value) {
-        return (int) Math.ceil(value);
-    }
-
-    public static Integer usingMathFloor(Double value) {
-        return (int) Math.floor(value);
-    }
-
-    public static Integer usingMathAbs(Double value) {
-        return (int) Math.abs(value);
-    }
-
-    public static Integer usingCast(Double value) {
-        return (int) value.doubleValue();
-    }
-
-}

java-numbers/src/test/java/com/baeldung/doubletolong/DoubleToLongUnitTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.doubletolong;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class DoubleToLongUnitTest {
+
+    final static double VALUE = 9999.999;
+
+    @Test
+    public void using_longValue() {
+        Assert.assertEquals(9999L, Double.valueOf(VALUE)
+            .longValue());
+    }
+
+    @Test
+    public void using_Math_Round() {
+        Assert.assertEquals(10000L, Math.round(VALUE));
+    }
+
+    @Test
+    public void using_Math_Ceil() {
+        Assert.assertEquals(10000L, Math.ceil(VALUE), 0);
+    }
+
+    @Test
+    public void using_Math_Floor() {
+        Assert.assertEquals(9999L, Math.floor(VALUE), 0);
+    }
+
+    @Test
+    public void using_Type_Cast() {
+        Assert.assertEquals(9999L, (long) VALUE);
+    }
+
+}