BAEL 4401 (#9913)

* BAEL-4401

* Update with master and resolve conflicts

core-java-modules/core-java-exceptions-3/pom.xml

@@ -30,5 +30,4 @@
         <!-- testing -->
         <assertj-core.version>3.10.0</assertj-core.version>
     </properties>
-
-</project>
+</project>

core-java-modules/core-java-exceptions-3/src/main/java/com/baeldung/nullmethodparameter/NullParameterExample.java

@@ -0,0 +1,17 @@
+package com.baeldung.nullmethodparameter;
+
+public class NullParameterExample {
+    public void processSomethingNotNull(Object myParameter) {
+        if (myParameter == null) {
+            throw new IllegalArgumentException("Parameter 'myParameter' cannot be null");
+        }
+        //Do something with the parameter
+    }
+    
+    public void processSomethingElseNotNull(Object myParameter) {
+        if (myParameter == null) {
+            throw new NullPointerException("Parameter 'myParameter' cannot be null");
+        }
+        //Do something with the parameter
+    }
+}

core-java-modules/core-java-exceptions-3/src/test/java/com/baeldung/nullmethodparameter/NullParameterExampleUnitTest.java

@@ -0,0 +1,17 @@
+package com.baeldung.nullmethodparameter;
+
+import org.junit.Test;
+
+public class NullParameterExampleUnitTest {
+    @Test(expected = IllegalArgumentException.class)
+    public void givenNullParameter_whenProcessSomethingNotNull_thenIllegalArgumentException() {
+        NullParameterExample example = new NullParameterExample();
+        example.processSomethingNotNull(null);
+    }
+    
+    @Test(expected = NullPointerException.class)
+    public void givenNullParameter_whenProcessSomethingElseNotNull_thenNullPointerException() {
+        NullParameterExample example = new NullParameterExample();
+        example.processSomethingElseNotNull(null);
+    }
+}