How to mock the HttpServletRequest?

Question

I have a function that looks for a query parameter and returns a boolean:

  public static Boolean getBooleanFromRequest(HttpServletRequest request, String key) {
        Boolean keyValue = false;
        if(request.getParameter(key) != null) {
            String value = request.getParameter(key);
            if(keyValue == null) {
                keyValue = false;
            }
            else {
                if(value.equalsIgnoreCase("true") || value.equalsIgnoreCase("1")) {
                    keyValue = true;
                }
            }
        }
        return keyValue;
    }

I have both junit and easymock in my pom.xml, how do I go about mocking the HttpServletRequest ?

The below answer this question as written well, but I would normally advocate for refactoring the code so that most of the non-trivial logic is in at a more appropriate level of abstraction. If that's possible, then mocking HttpServletRequest becomes unnecessary. — James Kingsbery, Jul 31 '14 at 21:15

score 28 · Answer 1 · edited Jul 01 '16 at 00:08

28

Use some mocking framework e.g. Mockito or JMock which comes with mocking capacity of such objects.

In Mockito, you can do mocking as:

 HttpServletRequest  mockedRequest = Mockito.mock(HttpServletRequest.class);

For details on Mockito, see: How do I drink it? on the Mockito site.

In JMock, you can do mocking as :

 Mockery context = new Mockery();
 HttpServletRequest  mockedRequest = context.mock(HttpServletRequest.class);

For details on jMock, please refer: jMock - Getting Started

edited Jul 01 '16 at 00:08

Mr. Lance E Sloan

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answered Oct 18 '12 at 01:55

Yogendra Singh

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Because they use generics with type inference like any good modern library should. – Hiro2k Oct 18 '12 at 02:06
1

You are passing `.class` as an argument to mock methods. – Yogendra Singh Oct 18 '12 at 02:07
@Hiro2k - That's what I would have expected, but I don't see any generics in the examples on the website... ? – Richard JP Le Guen Oct 18 '12 at 02:34
@RichardJPLeGuen http://docs.mockito.googlecode.com/hg/latest/org/mockito/Mockito.html#mock(java.lang.Class) See the generics in the method signature? – Hiro2k Oct 18 '12 at 19:58
@Hiro2k - I think I'm just confusing Java and C#. In C#, generic method calls include the generic in `<>` brackets (`mock(...)`) while it looks like that's not the case in Java. – Richard JP Le Guen Oct 18 '12 at 20:32

score 15 · Accepted Answer · edited Jan 20 '15 at 07:11

HttpServletRequest is much like any other interface, so you can mock it by following the EasyMock Readme

Here is an example of how to unit test your getBooleanFromRequest method

// static import allows for more concise code (createMock etc.)
import static org.easymock.EasyMock.*;

// other imports omitted

public class MyServletMock
{
   @Test
   public void test1()
   {
      // Step 1 - create the mock object
      HttpServletRequest req = createMock(HttpServletRequest.class);

      // Step 2 - record the expected behavior

      // to test true, expect to be called with "param1" and if so return true
      // Note that the method under test calls getParameter twice (really
      // necessary?) so we must relax the restriction and program the mock
      // to allow this call either once or twice
      expect(req.getParameter("param1")).andReturn("true").times(1, 2);

      // program the mock to return false for param2
      expect(req.getParameter("param2")).andReturn("false").times(1, 2);

      // switch the mock to replay state
      replay(req);

      // now run the test.  The method will call getParameter twice
      Boolean bool1 = getBooleanFromRequest(req, "param1");
      assertTrue(bool1);
      Boolean bool2 = getBooleanFromRequest(req, "param2");
      assertFalse(bool2);

      // call one more time to watch test fail, just to liven things up
      // call was not programmed in the record phase so test blows up
      getBooleanFromRequest(req, "bogus");

   }
}

score 11 · Answer 3 · answered Jul 23 '14 at 04:55

11

This is an old thread ... but the question is still relevant.

Another good choice is MockServiceRequest and MockServiceResponse in the Spring framework:

http://docs.spring.io/spring/docs/2.0.x/api/org/springframework/mock/web/package-summary.html

answered Jul 23 '14 at 04:55

FoggyDay

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score 2 · Answer 4 · answered Oct 18 '12 at 01:59

2

I don't know about easymock, but the book 'Unit Testing in Java: How Tests Drive the Code' by Johannes Link contained explanations of how to test Servlets using a library he'd build of dummy objects.

The companion site for the book is now gone (change in publishing company of something...) but the companion site from the original german publication is still up. From it, you can download the definitions of all the dummy objects.

answered Oct 18 '12 at 01:59

Richard JP Le Guen

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The publisher site links are giving 404 errors. – JohnK Feb 22 '22 at 22:21

score 0 · Answer 5 · edited Jan 20 '13 at 10:27

0

Have a look at Mockrunner: http://mockrunner.sourceforge.net/

It has a lot of easy to use Java EE mocks, including HttpServletRequest and HttpServletResponse.

edited Jan 20 '13 at 10:27

Arjan Tijms

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answered Nov 27 '12 at 21:10

mbelow

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How to mock the HttpServletRequest?

5 Answers5

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