BAEL-9352: Mocking Object Properties With Mockito

testing-modules/mockito-4/pom.xml

@@ -16,18 +16,29 @@
         <maven.compiler.source>23</maven.compiler.source>
         <maven.compiler.target>23</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <java.version>21</java.version>
     </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <version>4.0.1</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>21</source>
-                    <target>21</target>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
                 </configuration>
             </plugin>
         </plugins>
     </build>
 
-</project>
+</project>

testing-modules/mockito-4/src/main/java/com/baeldung/mockingobjectproperties/MockingObjectProperties.java

@@ -0,0 +1,15 @@
+package com.baeldung.mockingobjectproperties;
+
+import javax.servlet.http.HttpServletRequest;
+
+public class MockingObjectProperties {
+
+    public Object getSearchAttribute(HttpServletRequest request) {
+        return request.getAttribute("search");
+    }
+
+    public void printSearchAttribute(HttpServletRequest request) {
+        Object value = getSearchAttribute(request);
+        System.out.println("Search attribute: " + value);
+    }
+}

testing-modules/mockito-4/src/test/java/com/baeldung/mockingobjectproperties/MockingObjectPropertiesUnitTest.java

@@ -0,0 +1,73 @@
+package com.baeldung.mockingobjectproperties;
+
+import org.junit.jupiter.api.Test;
+import javax.servlet.http.HttpServletRequest;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.any;
+
+public class MockingObjectPropertiesUnitTest {
+
+    @Test
+    void givenMockRequest_whenUsedWithoutStubbing_thenReturnsNull() {
+        HttpServletRequest mockRequest = mock(HttpServletRequest.class);
+        mockRequest.setAttribute("search", "Mockito Example");
+
+        MockingObjectProperties helper = new MockingObjectProperties();
+        Object value = helper.getSearchAttribute(mockRequest);
+
+        assertNull(value, "Expected null because mock does not retain state");
+    }
+
+    @Test
+    void givenMockRequest_whenStubbedProperly_thenReturnsExpectedValue() {
+        HttpServletRequest mockRequest = mock(HttpServletRequest.class);
+        when(mockRequest.getAttribute("search"))
+          .thenReturn("Mockito Example");
+
+        MockingObjectProperties helper = new MockingObjectProperties();
+        Object value = helper.getSearchAttribute(mockRequest);
+
+        assertEquals("Mockito Example", value);
+    }
+
+    @Test
+    void givenMockRequest_whenSimulatingDynamicAttributes_thenBehavesLikeRealObject() {
+        HttpServletRequest mockRequest = mock(HttpServletRequest.class);
+        Map<String, Object> attributes = new HashMap<>();
+
+        when(mockRequest.getAttribute(anyString()))
+          .thenAnswer(invocation -> attributes.get(invocation.getArgument(0)));
+
+        doAnswer(invocation -> {
+            attributes.put(invocation.getArgument(0), invocation.getArgument(1));
+            return null;
+        }).when(mockRequest).setAttribute(anyString(), any());
+
+        MockingObjectProperties helper = new MockingObjectProperties();
+
+        mockRequest.setAttribute("search", "Mockito Example");
+        Object value = helper.getSearchAttribute(mockRequest);
+
+        assertEquals("Mockito Example", value);
+    }
+
+    @Test
+    void givenMockRequest_whenVerifyingInteractions_thenWorksAsExpected() {
+        HttpServletRequest mockRequest = mock(HttpServletRequest.class);
+
+        mockRequest.setAttribute("search", "Mockito Example");
+        mockRequest.getAttribute("search");
+
+        verify(mockRequest)
+          .setAttribute("search", "Mockito Example");
+        verify(mockRequest)
+          .getAttribute("search");
+        verify(mockRequest, never())
+          .getAttribute("nonexistent");
+    }
+}