Creating a mock HttpServletRequest out of a url string?

Simplest ways to mock an HttpServletRequest:

1. Create an anonymous subclass:

   HttpServletRequest mock = new HttpServletRequest ()
   {
       private final Map<String, String[]> params = /* whatever */
   
       public Map<String, String[]> getParameterMap()
       {
           return params;
       }
   
       public String getParameter(String name)
       {
           String[] matches = params.get(name);
           if (matches == null || matches.length == 0) return null;
           return matches[0];
       }
   
       // TODO *many* methods to implement here
   };
   

2. Use jMock, Mockito, or some other general-purpose mocking framework:

   HttpServletRequest mock = context.mock(HttpServletRequest.class); // jMock
   HttpServletRequest mock2 = Mockito.mock(HttpServletRequest.class); // Mockito
   

3. Use HttpUnit's ServletUnit and don't mock the request at all.

Here it is how to use MockHttpServletRequest:

// given
MockHttpServletRequest request = new MockHttpServletRequest();
request.setServerName("www.example.com");
request.setRequestURI("/foo");
request.setQueryString("param1=value1&param");

// when
String url = request.getRequestURL() + '?' + request.getQueryString(); // assuming there is always queryString.

// then
assertThat(url, is("http://www.example.com:80/foo?param1=value1&param"));

You would generally test these sorts of things in an integration test, which actually connects to a service. To do a unit test, you should test the objects used by your servlet's doGet/doPost methods.

In general you don't want to have much code in your servlet methods, you would want to create a bean class to handle operations and pass your own objects to it and not servlet API objects.

Spring has MockHttpServletRequest in its spring-test module.

If you are using maven you may need to add the appropriate dependency to your pom.xml. You can find spring-test at mvnrepository.com.