Test made using Mockito and JUnit

javax-servlets/src/main/java/com/root/FormServlet.java

@@ -7,6 +7,7 @@ import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import java.io.PrintWriter;
 
 @WebServlet(name = "FormServlet", urlPatterns = "/calculateServlet")
 public class FormServlet extends HttpServlet {
@@ -19,9 +20,12 @@ public class FormServlet extends HttpServlet {
         String weight = request.getParameter("weight");
 
         try {
-            Double bmi = calculateBMI(Double.parseDouble(weight), Double.parseDouble(height));
-
+            double bmi = calculateBMI(Double.parseDouble(weight), Double.parseDouble(height));
             request.setAttribute("bmi", bmi);
+
+            PrintWriter out= response.getWriter();
+            out.write(String.valueOf(bmi));
+
             RequestDispatcher dispatcher = request.getRequestDispatcher("index.jsp");
             dispatcher.forward(request, response);
         } catch (Exception e) {
@@ -30,15 +34,8 @@ public class FormServlet extends HttpServlet {
         }
     }
 
-    @Override
-    protected void doGet(HttpServletRequest request, HttpServletResponse response)
-            throws ServletException, IOException {
-
-        // do something else here
-    }
-
     private Double calculateBMI(Double weight, Double height) {
 
         return weight / (height * height);
     }
-}
+}

javax-servlets/src/test/java/com/root/FormServletTest.java

@@ -1,34 +1,51 @@
 package com.root;
 
+import org.junit.Before;
 import org.junit.Test;
-import org.mockito.Mockito;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
 
+import javax.servlet.RequestDispatcher;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
-/**
- * Created by shubham on 27/11/16.
- */
-public class FormServletTest extends Mockito {
+public class FormServletTest {
+
+    @Mock
+    HttpServletRequest request;
+
+    @Mock
+    HttpServletResponse response;
+
+    @Mock
+    RequestDispatcher requestDispatcher;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+    }
 
     @Test
     public void testFormServlet() throws Exception {
 
-        HttpServletRequest request = mock(HttpServletRequest.class);
-        HttpServletResponse response = mock(HttpServletResponse.class);
+        when(request.getParameter("height")).thenReturn("2");
+        when(request.getParameter("weight")).thenReturn("80");
 
-        when(request.getParameter("userName")).thenReturn("baeldung");
-        when(request.getParameter("userPlanet")).thenReturn("Mars");
-
-        PrintWriter writer = new PrintWriter(new StringWriter());
-        when(response.getWriter()).thenReturn(writer);
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        when(response.getWriter()).thenReturn(pw);
 
         new FormServlet().doPost(request, response);
 
-        assertTrue(request.getParameter("userName").contains("baeldung"));
+        verify(request).setAttribute("bmi", 20.0);
+
+        String result = sw.getBuffer().toString().trim();
+        assertEquals("20.0", result);
     }
 }