Merge pull request #10458 from sk1418/BAEL-4709_isAbstract

improvement

core-java-modules/core-java-reflection-2/src/main/java/com/baeldung/reflection/check/abstractclass/InterfaceExample.java

@@ -0,0 +1,4 @@
+package com.baeldung.reflection.check.abstractclass;
+
+public interface InterfaceExample {
+}

core-java-modules/core-java-reflection-2/src/test/java/com/baeldung/reflection/check/abstractclass/AbstractExampleUnitTest.java

@@ -1,16 +1,36 @@
 package com.baeldung.reflection.check.abstractclass;
 
-import java.lang.reflect.Modifier;
-
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
+import java.lang.reflect.Modifier;
+import java.util.Date;
+
 class AbstractExampleUnitTest {
 
     @Test
-    void givenAbstractClass_whenCheckModifierIsAbstract_thenTrue() throws Exception {
+    void givenAbstractClass_whenCheckModifierIsAbstract_thenTrue() {
         Class<AbstractExample> clazz = AbstractExample.class;
         Assertions.assertTrue(Modifier.isAbstract(clazz.getModifiers()));
     }
 
+    @Test
+    void givenInterface_whenCheckModifierIsAbstract_thenTrue() {
+        Class<InterfaceExample> clazz = InterfaceExample.class;
+        Assertions.assertTrue(Modifier.isAbstract(clazz.getModifiers()));
+    }
+
+    @Test
+    void givenAbstractClass_whenCheckIsAbstractClass_thenTrue() {
+        Class<AbstractExample> clazz = AbstractExample.class;
+        int mod = clazz.getModifiers();
+        Assertions.assertTrue(Modifier.isAbstract(mod) && !Modifier.isInterface(mod));
+    }
+
+    @Test
+    void givenConcreteClass_whenCheckIsAbstractClass_thenFalse() {
+        Class<Date> clazz = Date.class;
+        int mod = clazz.getModifiers();
+        Assertions.assertFalse(Modifier.isAbstract(mod) && !Modifier.isInterface(mod));
+    }
 }