Merge pull request #9959 from j0rdanit0/BAEL-4534

Added code examples for BAEL-4534

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/checkclassexistence/CheckClassExistenceUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.checkclassexistence;
+
+import org.junit.Test;
+
+public class CheckClassExistenceUnitTest {
+
+    public static class InitializingClass {
+        static {
+            if (true) { //enable throwing of an exception in a static initialization block
+                throw new RuntimeException();
+            }
+        }
+    }
+
+    @Test(expected = ClassNotFoundException.class) //thrown when class does not exist
+    public void givenNonExistingClass_whenUsingForName_thenClassNotFound() throws ClassNotFoundException {
+        Class.forName("class.that.does.not.exist");
+    }
+
+    @Test
+    public void givenExistingClass_whenUsingForName_thenNoException() throws ClassNotFoundException {
+        Class.forName("java.lang.String");
+    }
+
+    @Test(expected = ExceptionInInitializerError.class) //thrown when exception occurs inside of a static initialization block
+    public void givenInitializingClass_whenUsingForName_thenInitializationError() throws ClassNotFoundException {
+        Class.forName("com.baeldung.checkclassexistence.CheckClassExistenceUnitTest$InitializingClass");
+    }
+
+    @Test
+    public void givenInitializingClass_whenUsingForNameWithoutInitialization_thenNoException() throws ClassNotFoundException {
+        Class.forName("com.baeldung.checkclassexistence.CheckClassExistenceUnitTest$InitializingClass", false, getClass().getClassLoader());
+    }
+}