2011/08/05 - Jakarta Cactus has been retired.

For more information, please explore the Attic.

When to use?

Your test case class should extend ServletTestCase whenever you are unit testing:

  • Servlets,
  • Any java code that uses Servlet API objects (HttpServletRequest, ...)

Provided Implicit Objects

Cactus automatically initializes the implicit objects for you and they are made available to your setUp(), testXXX() and tearDown() methods as instance variables of the ServletTestCase class (and thus as instance variables of your test case class as it extends ServletTestCase). You may ask yourself how Cactus initializes these objects. The mechanism is described in the How it works guide. The provided implicit objects are:

request

Instance variable name request
Class name org.apache.cactus.server.HttpServletRequestWrapper , which inherits from javax.servlet.http.HttpServletRequest

Cactus wraps methods of the original HTTP request in order to return the HTTP related parameters set up in the beginXXX() method. Thus, you will be able to pass this request object to your code to test and set the needed parameter in the beginXXX() method.

For example, if your code under test calls getCookies() on the request object that you have passed to it, it will return the cookies that you have added to the HTTP request in beginXXX() by calling the WebRequest.addCookie() method.

See the javadoc for the org.apache.cactus.WebRequest interface and the org.apache.cactus.server.HttpServletRequestWrapper class for all details. You should also look at the samples provided in the Cactus distribution.

Additional methods

Cactus provides some additional methods to ease writing tests (see the javadoc for full details). These methods are provided because it is not easy (if not downright impossible in some cases) to simulate them with real configuration data:

  • setRemoteIPAddress(): sets the remote IP address that will be returned by getRemoteIPAddress(),
  • setRemoteHostName(): sets the remote Host name that will be returned by getRemoteHostName(),
  • setRemoteUser(): sets the remote user name that will be returned by getRemoteUser().

response

Instance variable name response
Class name javax.servlet.http.HttpServletResponse
Cactus does not wrap the response.

config

Instance variable name config
Class name org.apache.cactus.server.ServletConfigWrapper , which inherits from javax.servlet.ServletConfig
Cactus wraps the original Servlet Config for two reasons:
  • In order to provide additional methods. For example, it is possible to initialise parameters without setting them in web.xml, etc...,
  • So that it can return a wrapped Servlet Context instead of the original one. This is because the Servlet Context is used to perform forwards and includes and we need to pass to these methods the original request and response. As we have wrapped the request, we need to wrap the Servlet Context to pass the original request (and not the wrapped one).
The config implicit object will contain all initialisation parameters defined in web.xml under the Servlet Redirector servlet definition. See the javadoc for the org.apache.cactus.server.ServletConfigWrapper class for all details. You should also look at the samples provided in the Cactus distribution.

Additional methods

Additional methods provided:
  • setInitParameter(): sets an initialisation parameter (as if it has been defined in the web.xml file),
  • setServletName(): sets the Servlet name that will be returned by getServletName() (if not set, the Cactus Servlet redirector name will be returned).

ServletContextWrapper

This is not an implicit object per see (as it is not accessible as an instance variable). It is available by calling config.getServletContext(). However, Cactus wraps the ServletContext in a ServletContextWrapper in order to take into account simulated URLs and provide additional methods to help write tests. See the javadoc for the org.apache.cactus.server.ServletContextWrapper class for all details. You should also look at the samples provided in the Cactus distribution.

Additional methods

Additional methods provided:

  • getLogs(): returns the text that has been logged by calls to ServletContext.log() methods. This is a helper method that makes it easy to assert what is logged.
  • setInitParameter(): sets an initialisation parameter (as if it has been defined in the web.xml file, using the <context-param> element).

session

Instance variable name session
Class name javax.servlet.http.HttpSession
Cactus does not wrap the response. By default, Cactus always creates an HTTP session for your test case. It is possible to tell it not to do so by calling the WebRequest.setAutomaticSession(false) method (it is true by default). This could be useful for cases where your code under test verifies branches when "request.getSession(false)" is null.

Tips and Tricks

Parameter initialisation

If your code under test make use of any of the servlet methods inherited from javax.servlet.GenericServlet (these are the log(), getServletConfig(), ... methods), then you need to call the init(ServletConfig) method of your servlet to initialise its internal ServletConfig object.

For example:

public void testXXX()
{
    MyServletToTest servlet = new MyServletToTest();
    servlet.init(config);

    // Call a method to test that uses a method inherited from Generic Servlet
    servlet.someMethodToTest();

[...]
}

See the samples provided as part of the Cactus distribution.

Sample

This is a very basic sample intended to give you a flavour of Servlet unit testing. Check the distribution samples for extensive examples.

This example is for Cactus 1.2 and above as it uses the new WebRequest and WebResponse objects.
public void beginXXX(WebRequest theRequest)
{
    // Set up HTTP related parameters
    theRequest.setURL("jakarta.apache.org", "/mywebapp", "/test/test.jsp",
        null, null);
    theRequest.addCookie("cookiename", "cookievalue");
}

public void testXXX()
{
    MyServletToTest servlet = new MyServletToTest();
    servlet.init(config);

    // Call method to test
    servlet.methodToTest();

    // Perform some server side asserts
    assertEquals("someValue", session.getAttribute("someAttribute"));
    assertEquals("jakarta.apache.org", request.getServerName());
}

public void endXXX(WebResponse theResponse)
{
    // Asserts the returned HTTP response

    Cookie cookie = theResponse.getCookie("someCookie");
    assertEquals("someValue2", cookie.getValue());

    assertEquals("some content here", theResponse.getText());
}