Need some suggestion on one of the scenario for sling servlet in AEM.
In AEM we can call servlet via AJAX call in javascript, and can specify the requested path in ajax like :
"type: 'POST',
url:'/bin/calculatorServlet', "
In sightly itself, in form action i can specify the path of servlet like "/bin/myservlet" to invoke.
Just wondering if someone can tell what approach we should use to call a sling servlet and what are the benifits of using one above another.
what i understand is if we require the output from servlet, we can get in ajax response and process.
Related
I'm wondering is it possible to have path variable in server.servlet-path with DispatcherServlet? I know of course it possible in controller, but I'd like to have it in one place instead of updating 70 endpoints.
Like:
server.servlet-path=/{client-name}/api/v4
And for example that client-name will be available in request attributes, headers, etc.
Or I need to implement my own dispatcher which will do that logic?
I want to use Spring MVC 3.0 to build interfaces for AJAX transactions. I want the results to be returned as JSON, but I don't necessarily want the web pages to be built with JSP. I only want requests to the controllers to be intercepted/routed through the DispatcherServlet and the rest of the project to continue to function like a regular Java webapp without Spring integration.
My thought was to define the servlet-mapping url pattern in web.xml as being something like "/controller/*", then have the class level #RequestMapping in my controller to be something like #RequestMapping("/controller/colors"), and finally at the method level, have #RequestMapping(value = "/controller/colors/{name}", method = RequestMethod.GET).
Only problem is, I'm not sure if I need to keep adding "/controller" in all of the RequestMappings and no matter what combo I try, I keep getting 404 requested resource not available errors.
The ultimate goal here is for me to be able to type in a web browser "http://localhost:8080/myproject/controller/colors/red" and get back the RGB value as a JSON string.
You are not correct about needing to add the entire path everywhere, the paths are cumulative-
If you have a servlet mapping of /controller/* for the Spring's DispatcherServlet, then any call to /controller/* will be handled now by the DispatcherServlet, you just have to take care of rest of the path info in your #RequestMapping, so your controller can be
#Controller
#RequestMapping("/colors")
public class MyController{
#RequestMapping("/{name}
public String myMappedMethod(#PathVariable("name") String name, ..){
}
}
So now, this method will be handled by the call to /controller/colors/blue etc.
I don't necessarily want the web pages to be built with JSP
Spring MVC offers many view template integration options, from passthrough to raw html to rich templating engines like Velocity and Freemarker. Perhaps one of those options will fit what you're looking for.
I have a servlet that responds to a URL and then forwards to a JSP in a typical MVC pattern.
Many pages share the same page head so in the JSP there is an include to head.jsp
head.jsp is placed inside WEB-INF so that it cannot be accessed directly.
Now I find that I need to add some control to the head. Rather than forwarding to WEB-INF/head.jsp and putting scriptlets in I would like to forward to a servlet instead.
How can I forward from the JSP to a servlet without mapping that servlet to a URL as I do not want to give direct access to this servlet.
Or to put it another way is there a servlet equivalent of WEB-INF to hide it from direct access? So the servlet can only be called via an include?
Rather than forwarding to WEB-INF/head.jsp and putting scriptlets in I would like to forward to a servlet instead.
It's indeed possible to do this (using <jsp:include> or a small scriptlet that dispatches), but I'm not sure whether this is really the best approach. The Servlet would either write directly to the response or would put some data in the request scope that the JSP can pick up later.
Writing directly to the response is a bit debatable today and for the other approach you don't need a Servlet at all.
The idiomatic way is to use some helper bean that contains the logic. The original Servlet you mentioned can put this bean into request scope, or you can use the <jsp:usebean> tag. Reference the data the helper bean prepared via expression language or very simple scriptlets.
So the servlet can only be called via an include?
If you still want to go this route, there might be an option of securing the Servlet behind a role and then giving the head.jsp a run-as role in web.xml:
<servlet>
<servlet-name>headInclude</servlet-name>
<jsp-file>/WEB-INF/head.jsp</jsp-file>
<run-as>
<role-name>SYSTEM</role-name>
</run-as>
</servlet>
disclaimer: I have never tried this myself, just pointing in a possible direction.
I'm creating a Spring MVC application that will have a controller with 'RequestMapping'-annotated methods, including a JSON method. It currently has static content that resides in webapps/static, and the app itself resides in webapps/myapp. I assume that Catalina's default servlet is handling the static content, and my *.htm url-pattern in web.xml is returning the request for my JSP page, but I haven't been able to get the JSON method to be called. How do I write the url-pattern in the servlet mapping to do so? Using /* has not worked; it prevents the app from being accessed at all. Is there anything else to be aware of?
I've learned of the default url-pattern, '/', which appears to be a match for my JSON request.
I am trying to follow this example
but I can't understand this part:
Imagine also that the servlet's context path is myServer/myApp/servlets. The servlet container would direct a request with URL myServer/myApp/createUser.do myServlet to myServlet, because the request URL matches the pattern *.do. Servlet myServlet can extract the requested operation's name from the request URL.
I can't understand the request, shouldn't it be myServer/myApp/myServlet/createUser.do? And how can one create such a request? Can I just put myServlet/createUser.do in the action of a form?
Thank you for your time.
Iulia
No, you create a mapping to your servlet for myapp. The servlet name itself usually never shows in the request URL. So every request that goes to myapp will be redirected to your servlet if it matches. That means that your mapping
http://myserver/myapp/*.do
redirects every request with a .do to your servlet. Now the servlet has to deal with the request URL (e.g. render the view for createUser)