I want to check if a Sling ressource already exists. Currently I use CQ.HTTP.get(url) to accomplish this. The problem is that if the ressource does not exist, JS logs a 404 error to the console which I think is ugly.
Is there a better way to check if a ressource exists which doesn't pollute the console?
Here is a simple servlet that does what you're asking:
/**
* Servlet that checks if resource exists.
*/
@SlingServlet
(
paths = "/bin/exists",
extensions = "html",
methods = "GET"
)
public class ResourceExistsServlet extends SlingSafeMethodsServlet {
@Override
protected void doGet(final SlingHttpServletRequest request,
final SlingHttpServletResponse response) throws ServletException, IOException {
// get the resource by the suffix
// for example, in the request /bin/exists.htm/apps, "/apps" is the suffix and that's the resource obtained here.
Resource resource = request.getRequestPathInfo().getSuffixResource();
// resource is null, does not exist, not null, exists
boolean exists = resource != null;
// make the response content type JSON
response.setContentType(JSONResponse.APPLICATION_JSON_UTF8);
// Write the json to the response
// TODO: use a library for more complicated JSON, like google's gson. In this case, this string suffices.
response.getWriter().write("{\"exists\": "+exists+"}");
}
}
And here is some sample JS to call the servlet:
// Check if a path exists exists
function exists(path){
return $.getJSON("/bin/exists.html"+path);
}
// check if /apps exists
exists("/apps")
.then(function(res){console.log(res.exists)})
// prints: true
// check if /apps123 exists
exists("/apps123")
.then(function(res){console.log(res.exists)})
// prints: false
