Spring Web Flow: setting request parameter for JUnit test

Question

Introduction

I have a Java/Tomcat/Spring 2.5/Spring Webflow 2.0.9 web application. To test some of the pages I have created JUnit tests, which set values to the form objects and mimic the requests coming from the browser. The JUnit test class looks something like this:

@TestExecutionListeners({ DependencyInjectionTestExecutionListener.class })
@ContextConfiguration(locations = { "classpath:/WebTests-context.xml", "classpath:/messageSourceConfig.xml" })
@RunWith(SpringJUnit4ClassRunner.class)

public class InitechValidatorTests {

    protected MockHttpSession session;
    protected MockHttpServletRequest request;

    //test methods omitted

    protected void startSession() {
        session = new MockHttpSession();
    }

    protected void endSession() {
        session.clearAttributes();
        session = null;
    }

    protected void startRequest() {
        request = new MockHttpServletRequest();
        request.setSession(session);
        RequestContextHolder.setRequestAttributes(new ServletRequestAttributes(request));

        MockRequestContext mrc = new MockRequestContext();
        org.springframework.webflow.execution.RequestContextHolder.setRequestContext(mrc);

        MessageContext messageContext = org.springframework.webflow.execution.RequestContextHolder.getRequestContext()
                .getMessageContext();
        this.validationContext.setMessageContext(messageContext);
    }

    protected void endRequest() {
        ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).requestCompleted();
        RequestContextHolder.resetRequestAttributes();
        request = null;

        org.springframework.webflow.execution.RequestContextHolder.setRequestContext(null);
    }
}

For each test method I call the startRequest and endRequest methods (startSession is called before the first test method and endSession after the last test method). Without this construct I couldn't use e.g. RequestContextHolder in the code I'm testing.

The problem

In the class to test I read the contents of a request parameter from the web flow like this:

RequestContext requestContext = RequestContextHolder.getRequestContext();
ExternalContext externalContext = requestContext.getExternalContext();
String printPressed = externalContext.getRequestParameterMap().get("printPressed");

I would need to set the "printPressed" request parameter in my JUnit test method like this:

org.springframework.webflow.execution.RequestContext requestContext = org.springframework.webflow.execution.RequestContextHolder
                    .getRequestContext();
ExternalContext externalContext = requestContext.getExternalContext();
Map requestParamMap = externalContext.getRequestParameterMap().asMap();
requestParamMap.put("printPressed", "true");

That is, however impossible because the map is immutable and results in an UnsupportedOperationException.

The question is: how to set a request parameter to the requestParameterMap in the class org.springframework.webflow.context.ExternalContext? The parameter map returned by getRequestParameterMap is immutable, so I cannot add the parameter there. I noticed that there is e.g. an object MockParameterMap, which sounds promising: "A extension of parameter map that allows for mutation of parameters. Useful as a stub for testing."

How can I inject the MockParameterMap to the ExternalContext in the test class? Or is there some other way to set the request parameters for unit testing?

Answer 1

Solved the problem by modifying the startRequest method so that I set the MockParameterMap to a new MockExternalContext object, which is set to the MockRequestContext followingly:

MockParameterMap mpp = new MockParameterMap();
MockExternalContext mec = new MockExternalContext(mpp);
mrc.setExternalContext(mec);

Then in the JUnit test method I can set the parameter followingly:

org.springframework.webflow.execution.RequestContext requestContext = org.springframework.webflow.execution.RequestContextHolder
                    .getRequestContext();
ExternalContext externalContext = requestContext.getExternalContext();
MockParameterMap requestParameterMap = (MockParameterMap) externalContext.getRequestParameterMap();
requestParameterMap.put("printPressed", "true");