BAEL-5524: Mock HttpServletRequest + tests (#12242)

* BAEL-5524: Mock HttpServletRequest + tests

* BAEL-5524: Fixed JUnit tests + dependency

* BAEL-5524: Updated test parameters

javax-servlets-2/pom.xml

@@ -39,6 +39,18 @@
             <artifactId>jstl</artifactId>
             <version>${jstl.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.jmockit</groupId>
+            <artifactId>jmockit</artifactId>
+            <version>${jmockit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <version>${spring-test.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.apache.httpcomponents</groupId>
             <artifactId>httpclient</artifactId>
@@ -53,9 +65,26 @@
         </dependency>
     </dependencies>
 
+	<build>
+		<plugins>
+			<plugin>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<version>${maven-surefire-plugin.version}</version>
+				<configuration>
+					<argLine>
+          			  -javaagent:"${settings.localRepository}"/org/jmockit/jmockit/${jmockit.version}/jmockit-${jmockit.version}.jar
+         			</argLine>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
     <properties>
         <org.apache.httpcomponents.version>4.5.13</org.apache.httpcomponents.version>
         <javax.servlet-api.version>4.0.1</javax.servlet-api.version>
+        <jmockit.version>1.49</jmockit.version>
+        <spring-test.version>5.3.20</spring-test.version>
+        <maven-surefire-plugin.version>2.22.2</maven-surefire-plugin.version>
     </properties>
 
 </project>

javax-servlets-2/src/main/java/com/baeldung/servlets/UserServlet.java

@@ -0,0 +1,24 @@
+package com.baeldung.servlets;
+
+import java.io.IOException;
+
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+@WebServlet(name = "UserServlet", urlPatterns = "/user")
+public class UserServlet extends HttpServlet {
+
+    private static final long serialVersionUID = 2923732283720972121L;
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
+        String firstName = request.getParameter("firstName");
+        String lastName = request.getParameter("lastName");
+
+        response.getWriter()
+            .append("Full Name: " + firstName + " " + lastName);
+    }
+
+}

javax-servlets-2/src/test/java/com/baeldung/servlets/UserServletUnitTest.java

@@ -0,0 +1,93 @@
+package com.baeldung.servlets;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
+
+import mockit.Expectations;
+import mockit.Mocked;
+
+class UserServletUnitTest {
+
+    private UserServlet servlet;
+    private StringWriter writer;
+    
+    @Mocked
+    HttpServletRequest mockRequest;
+    @Mocked
+    HttpServletResponse mockResponse;
+
+    @BeforeEach
+    public void setUp() throws IOException {
+        servlet = new UserServlet();
+        writer = new StringWriter();
+    }
+
+    @Test
+    void givenHttpServletRequest_whenUsingAnonymousClass_thenReturnsParameterValues() throws IOException {
+        final Map<String, String[]> params = new HashMap<>();
+        params.put("firstName", new String[] { "Anonymous Class" });
+        params.put("lastName", new String[] { "Test" });
+
+        servlet.doGet(TestUtil.getRequest(params), TestUtil.getResponse(writer));
+
+        assertThat(writer.toString()).isEqualTo("Full Name: Anonymous Class Test");
+    }
+
+    @Test
+    void givenHttpServletRequest_whenMockedWithMockito_thenReturnsParameterValues() throws IOException {
+        // mock HttpServletRequest & HttpServletResponse
+        HttpServletRequest request = mock(HttpServletRequest.class);
+        HttpServletResponse response = mock(HttpServletResponse.class);
+
+        // mock the returned value of request.getParameterMap()
+        when(request.getParameter("firstName")).thenReturn("Mockito");
+        when(request.getParameter("lastName")).thenReturn("Test");
+        when(response.getWriter()).thenReturn(new PrintWriter(writer));
+
+        servlet.doGet(request, response);
+
+        assertThat(writer.toString()).isEqualTo("Full Name: Mockito Test");
+    }
+
+    @Test
+    void givenHttpServletRequest_whenMockedWithJMockit_thenReturnsParameterValues() throws IOException {
+        
+        new Expectations() {{
+            mockRequest.getParameter("firstName"); result = "JMockit";
+            mockRequest.getParameter("lastName"); result = "Test";
+            mockResponse.getWriter(); result = new PrintWriter(writer);
+         }};
+        
+        servlet.doGet(mockRequest, mockResponse);
+        
+        assertThat(writer.toString()).isEqualTo("Full Name: JMockit Test");
+    }
+
+    @Test
+    void givenHttpServletRequest_whenUsingMockHttpServletRequest_thenReturnsParameterValues() throws IOException {
+        MockHttpServletRequest request = new MockHttpServletRequest();
+        request.setParameter("firstName", "Spring");
+        request.setParameter("lastName", "Test");
+        MockHttpServletResponse response = new MockHttpServletResponse();
+
+        servlet.doGet(request, response);
+
+        assertThat(response.getContentAsString()).isEqualTo("Full Name: Spring Test");
+    }
+
+}