Struts 2 - Sending mail with embedded URL

Question

For a project for my company, I have to send emails containing embedded URLs, which the user will be prompted to follow.

For example, a person registers on the website, and then the Struts2 application sends an email to that person in which there is a URL to confirm the subscription.

So far, the form submission, and sending the email (from inside the action), work just fine. The problem on which I'm stuck is that I can't find a way to generate the URL I'd like to embed in the mail body.

I must be doing it the wrong way, but I was thinking about something like what follows:

public String send() throws Exception {
    StringBuffer body = new StringBuffer();

    HashMap<String, String> params = new HashMap<String, String>();
    params.put("id", "xxxxxyyyyyaaaaa");

    body.append("Veuillez vous rendre ici :");
    body.append(UrlManager.getUrlForAction("action", params));

    SendMail sendMail = new SendMail();
    sendMail.send("me@me.fr", "Information", body.toString());

    return SUCCESS;
}

where there would be a UrlManager (something that could be made available by the framework) with a method getUrlForAction() that gets an action and its parameters as input and that outputs a String containing the corresponding URL (like http://mysite.mycompany.com/confirm?id=xxxxxyyyyyaaaaa).

Does anyone have any ideas or pointers on how to do that?

EDIT:

I tried using UrlProvider, but I get a null pointer exception on the determineActionUrl call. Maybe I'm using it the wrong way.

HashMap<String,Object> params = new HashMap<String,Object>();
params.put("id", data.getMd5());

UrlProvider up = new ComponentUrlProvider(
                            new Component(ServletActionContext.getValueStack(ServletActionContext.getRequest())),
                            ServletActionContext.getRequest().getParameterMap());
downloadUrl = up.determineActionURL("confirm", "/", "GET",
                                    ServletActionContext.getRequest(),
                                    ServletActionContext.getResponse(),
                                    params,
                                    "http", true, true, true, true);

Answer 1

You need to create the properties (dependencies) in your action

@Inject
public void setActionMapper(ActionMapper actionMapper) {
  this.actionMapper = actionMapper;
}

private UrlHelper urlHelper;

@Inject
public void setUrlHelper(UrlHelper urlHelper) {
  this.urlHelper = urlHelper;
}

then in the action you could write something like

Map<String, Object> parameters = new HashMap<>();
ActionMapping mapping = new ActionMapping("action", "namespace", "", parameters);
String uri = actionMapper.getUriFromActionMapping(mapping);
String url  = urlHelper.buildUrl(uri, ServletActionContext.getRequest(), ServletActionContext.getResponse(), parameters, "http", true, false, true, false);

Answer 2

You may take a look at Struts' UrlProvider.determineActionURL, which does what you need.

UPDATE Indeed I needed to use this method some weeks ago and I remember some NPE's rising around... At the end, I was able to write the following code (adapted from my app):

String getMyActionUrl() throws Exception {

    ActionInvocation invocation = (ActionInvocation) ActionContext
            .getContext().get(ActionContext.ACTION_INVOCATION);

    org.apache.struts2.components.URL url = new org.apache.struts2.components.URL(invocation.getStack(), getServletRequest(),
            getServletResponse());
    url.addParameter("parameterToBeDeleted", null);
    url.addParameter("newParam", newValue);
    url.setActionMapper(new DefaultActionMapper());
    url.setUrlHelper(new DefaultUrlHelper());

    String myUrl = url
            .getUrlProvider()
            .determineActionURL(
                    "MyActionName",
                    invocation.getProxy().getNamespace(),
                    invocation.getProxy().getMethod(),
                    getServletRequest(),
                    getServletResponse(),
                    getServletRequest().getParameterMap(),
                    "http",
                    true, true, false, false);

    return myUrl;

}

Notes:

• MyActionName is here as a String -- not a great maintanable code. Make sure it matches the name you give to the action (which may differ from the name of the Action class handling calls to that action).

• http is hardcoded. Change if needed.