无法通过POST的sling servlet中的请求分派器重定向到AEM中的另一个页面

Question

I have a scenario where from one page in AEM, I need to call another AEM page in the same application and I need to pass some hidden parameters. I choose to do it via POST and below are the steps which I followed: From page "A", I did a form submission via POST to the sling servlet and passed some parameters. 2. In the servlet, using request dispatcher I redirected the same request and response to a different page in doPost method using the following code snippet:

          request.getRequestDispatcher("/content/company/en/apps/welcomepage.html").forward(request, response);

When I run the code, I am able to call the servlet through form submission but I am not able to redirect to a new page. I see the below error in logs:

18.10.2017 14:41:00.802 ERROR [127.0.0.1 [1508352060795] POST /bin/rap/welcomepage HTTP/1.1] org.apache.sling.servlets.post.impl.operations.ModifyOperation Exception during response processing. javax.jcr.nodetype.ConstraintViolationException: No matching property definition: appointmentTypeId = platform001d at org.apache.jackrabbit.oak.jcr.delegate.NodeDelegate.setProperty(NodeDelegate.java:522) at org.apache.jackrabbit.oak.jcr.session.NodeImpl$35.perform(NodeImpl.java:1375) at org.apache.jackrabbit.oak.jcr.session.NodeImpl$35.perform(NodeImpl.java:1363) at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.perform(SessionDelegate.java:208) at org.apache.jackrabbit.oak.jcr.session.ItemImpl.perform(ItemImpl.java:112) at org.apache.jackrabbit.oak.jcr.session.NodeImpl.internalSetProperty(NodeImpl.java:1363)

If I try the same code in doGet method it works fine. Also if I use response.sendRedirect("/content/company/en/apps/welcomepage.html") it works fine too. But the problem with this is it initiates it as a new request to the page and it looses all the parameters which I get from the form submission. Could someone please let me know like how can I redirect a request to a page in AEM via POST since I need to pass some hidden parameters whic should not be visible in the url ?

Answer 1

Here is the way I understand your question

1. User visits page "A"
2. User fills a form, then submits.
3. Your custom servlet handles the submitted POST request and calls: request.getRequestDispatcher("/content/company/en/apps/welcomepage.html").forward(request, response);
4. You get the ConstraintViolationException

Why do you get this exception?

Since you are using forward the POST request is forwarded to /content/company/en/apps/welcomepage.html that node is most likely of type cq:Page , which has constraints on which properties can be added. Think of it as a simple post request trying to store parameters on the cq:Page node.

What can you do?

Since I don't understand your use-case and particularly why you need to preserve the submit params, I cannot recommend a specific solution. However, since you don't want the parameters in the URL, here is a potential solution you can try:

1. In your servlet handler, see those hidden params to cookies on the response.
2. use response.sendRedirect("/content/company/en/apps/welcomepage.html")
3. On any of the components in /content/company/en/apps/welcomepage.html , you can get the request cookies and process them however you like. same way you wanted to process those hidden params.

Now the flow becomes:

1. User visits page "A"
2. User fills a form, then submits.
3. Your custom servlet handles the submitted POST request, adds your special params to cookies on the response, then calls response.sendRedirect("/content/company/en/apps/welcomepage.html")
4. User's browser receives a 301 response with the cookies, sets the cookies in the browser then requests "/content/company/en/apps/welcomepage.html"
5. Your components handle the request and get the params from the cookies, then retuns the appropriate response.