BAEL-870 How to Call a Method During Runtime Using Reflection (#1789)

* BAEL-870 How to Call a Method During Runtime Using Reflection

* Update OperationsUnitTest.java

Rename Test Name

core-java/src/main/java/com/baeldung/java/reflection/Operations.java

@@ -1,17 +1,21 @@
 package com.baeldung.java.reflection;
 
 public class Operations {
-    
+
     public double sum(int a, double b) {
         return a + b;
     }
-    
+
-    public static double multiply(float a, long b){
+    public static double multiply(float a, long b) {
         return a * b;
     }
 
     private boolean and(boolean a, boolean b) {
         return a && b;
     }
-    
+
+    protected int max(int a, int b) {
+        return a > b ? a : b;
+    }
+
 }

core-java/src/test/java/com/baeldung/java/reflection/OperationsUnitTest.java

@@ -14,23 +14,23 @@ public class OperationsUnitTest {
     public OperationsUnitTest() {
     }
 
-    @Test(expected=IllegalAccessException.class)
+    @Test(expected = IllegalAccessException.class)
-    public void givenObject_whenInvokePrivatedMethod_thenFail() throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException{
+    public void givenObject_whenInvokePrivateMethod_thenFail() throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
-        Method andInstanceMethod = Operations.class.getDeclaredMethod("and", boolean.class, boolean.class);
+        Method andPrivateMethod = Operations.class.getDeclaredMethod("and", boolean.class, boolean.class);
 
         Operations operationsInstance = new Operations();
-        Boolean result = (Boolean)andInstanceMethod.invoke(operationsInstance, true, false);
+        Boolean result = (Boolean) andPrivateMethod.invoke(operationsInstance, true, false);
 
         assertFalse(result);
     }
 
     @Test
     public void givenObject_whenInvokePrivateMethod_thenCorrect() throws Exception {
-        Method andInstanceMethod = Operations.class.getDeclaredMethod("and", boolean.class, boolean.class);
+        Method andPrivatedMethod = Operations.class.getDeclaredMethod("and", boolean.class, boolean.class);
-        andInstanceMethod.setAccessible(true);
+        andPrivatedMethod.setAccessible(true);
 
         Operations operationsInstance = new Operations();
-        Boolean result = (Boolean)andInstanceMethod.invoke(operationsInstance, true, false);
+        Boolean result = (Boolean) andPrivatedMethod.invoke(operationsInstance, true, false);
 
         assertFalse(result);
     }
@@ -40,17 +40,17 @@ public class OperationsUnitTest {
         Method sumInstanceMethod = Operations.class.getMethod("sum", int.class, double.class);
 
         Operations operationsInstance = new Operations();
-        Double result = (Double)sumInstanceMethod.invoke(operationsInstance, 1, 3);
+        Double result = (Double) sumInstanceMethod.invoke(operationsInstance, 1, 3);
-        
+
         assertThat(result, equalTo(4.0));
     }
-    
+
     @Test
     public void givenObject_whenInvokeStaticMethod_thenCorrect() throws Exception {
-        Method multiplyStaticMethod = Operations.class.getDeclaredMethod("multiply",float.class, long.class);
+        Method multiplyStaticMethod = Operations.class.getDeclaredMethod("multiply", float.class, long.class);
+
+        Double result = (Double) multiplyStaticMethod.invoke(null, 3.5f, 2);
 
-        Double result = (Double)multiplyStaticMethod.invoke(null, 3.5f, 2);
-        
         assertThat(result, equalTo(7.0));
     }
 

core-java/src/test/java/com/baeldung/java/reflection/operations/MoreOperationsUnitTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.java.reflection.operations;
+
+import com.baeldung.java.reflection.*;
+import static org.hamcrest.CoreMatchers.equalTo;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import org.junit.Test;
+import static org.junit.Assert.assertThat;
+
+public class MoreOperationsUnitTest {
+
+    public MoreOperationsUnitTest() {
+    }
+
+    @Test(expected = IllegalAccessException.class)
+    public void givenObject_whenInvokeProtectedMethod_thenFail() throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
+        Method maxProtectedMethod = Operations.class.getDeclaredMethod("max", int.class, int.class);
+
+        Operations operationsInstance = new Operations();
+        Integer result = (Integer) maxProtectedMethod.invoke(operationsInstance, 2, 4);
+        System.out.println("result = " + result);
+        assertThat(result, equalTo(4));
+    }
+
+    @Test
+    public void givenObject_whenInvokeProtectedMethod_thenCorrect() throws Exception {
+        Method maxProtectedMethod = Operations.class.getDeclaredMethod("max", int.class, int.class);
+        maxProtectedMethod.setAccessible(true);
+
+        Operations operationsInstance = new Operations();
+        Integer result = (Integer) maxProtectedMethod.invoke(operationsInstance, 2, 4);
+
+        assertThat(result, equalTo(4));
+    }
+
+}