Error Handling In Restlet
Open Source Tutorials User Guide Javadocs Download Forum Support Sign in Get started Restlet Blog Exception handling with Restlet Framework By: Thierry Templier | December 21, 2015 | Write a comment Restlet Framework provides several approaches to handle exceptions on both client and server sides. You can choose to use the Restlet Framework API itself or use a higher level approach based on custom exceptions and / or annotated exceptions. On the server side Restlet Framework provides several approaches to handle exceptions on the server side. They correspond to different needs and allow you to add flexibility when generating the corresponding response. Basic approach for exceptions Restlet Framework allows you to throw two kinds of exceptions within the annotated methods of server resources: The ResourceException exception itself corresponds to any exception that can occur within a server resource. User-defined exceptions (both checked and unchecked). In the case of checked exceptions, we need to add a throws clause in the method signatures. The Restlet Framework engine will then catch them and wrap them within a ResourceException one. That said, Restlet Framework provides an indirection level to deduce the response status code and content when an exception is thrown within a server resource. As a matter of fact, the ResourceException exception is generic and mandates to specify a status code when creating it. A good approach is to implement user-defined exceptions describing the potential errors. Then comes the status service of Restlet Framework. The element is responsible for creating the response content when an exception is thrown. The default implementation returns the description that comes along with a particular status code as text. Restlet Framework allows the service developer to override it and provides its own implementation. Registering a custom status service can simply be done within the Restlet Framework application class using the setStatusService() method, as described below: public class MyApplication extends Application { (...) public MyApplication() { (...) setStatusService(new MyCustomStatusService()); } } A custom status service needs to extend the StatusService class and override the following methods:
Exception handling withRestlet Posted on February 27, 2015 by templth Restlet provides several approaches to handle exceptions on both client and server sides. You can choose to be close to the Restlet API itself or use a higher level approach based on custom exceptions and / or annotated exceptions On the server side Restlet provides several approaches to handle exceptions on the server side. They correspond to different needs and allow to http://restlet.com/blog/2015/12/21/exception-handling-with-restlet-framework/ add flexibility when generating the corresponding response. Basic approach for exceptions Restlet allows to throw two kinds of exceptions within the annotated methods of server resources: The exception ResourceException itself that corresponds to any exception that can occur within a server resource. User-defined exceptions (both checked and unchecked exceptions). In the https://templth.wordpress.com/2015/02/27/exception-handling-with-restlet/ case of checked exceptions, we need to a throws in the method signatures. The Restlet engine will then catch them and wraps them within a ResourceException one. That said, Restlet provides an indirection level to deduce the response status code and content when an exception is thrown within a server resource. As a matter of fact, the exception ResourceException is generic and only accepts to specify status code when creating it. A good approach is to implement user-defined exceptions describing the potential errors. Then comes the status service of Restlet. The element is reponsible to create the response content when an exception is thrown. The default implementation returns description that comes along with a particular status code as text. Restlet allows the service developer to override it and provide its own implementation. Registering a custom status service can be simply done within the Restlet application class using the method setStatusService, as describ
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About http://stackoverflow.com/questions/33911768/how-do-i-send-an-error-response-in-restlet Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join http://restlet-discuss.1400322.n2.nabble.com/Handling-exceptions-errors-when-using-Restlet-for-Client-and-Server-td7578190.html the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up How do I send an error handling error response in Restlet? up vote 2 down vote favorite I have a Restlet ServerResource, which should process a GET request with a parameter user. If user is equal to some value, it should return some image, otherwise send an error response (404 or 403) indicating that the sender is not allowed to get the image. import org.restlet.data.MediaType; import org.restlet.representation.ObjectRepresentation; import org.restlet.representation.Representation; import org.restlet.resource.Get; import org.restlet.resource.ResourceException; error handling in import org.restlet.resource.ServerResource; public class GetMap extends ServerResource { @Get public Representation getImage() { final String user = getQuery().getValues("user"); if (user.equals("me")) { //Read map from file and return it byte[] data = readImage(); final ObjectRepresentation
in threaded view ♦ ♦ | Report Content as Inappropriate ♦ ♦ Handling exceptions/errors when using Restlet for Client and Server.... My question is similar to that raised at: http://restlet-discuss.1400322.n2.nabble.com/Sending-server-side-exceptions-error-codes-back-to-client-td7219795.html#a7229629, but since that has not been answered and this seems like a really basic issue, I thought I would try posting again. The question is simply this - how to get the details of an error/exception that occurs on the Restlet server back to my Restlet client? I can see how to do this if my client were just a browser (I could construct an HTML page on the server and return it). I thought that it would be pretty simple - set the Status code and Status description. But as the discussion above points out, that doesn't work. I then thought that I could just set the Status code and send back a String Representation of the error message. But that doesn't work either. In particular, if I have: msg = "error xyz occurred"; this.setStatus(Status.SERVER_ERROR_INTERNAL, msg); StringRepresentation result = new StringRepresentation(msg, MediaType.TEXT_PLAIN); return result; The client side call: commitsRep = commitsResource.get(); Sets commitsRep == null (!). Note: it is only set to null when the status != 200. So, I could set the status to 200 and then return the StringRepresentation and then on the client, check to see if I have a StringRepresentation (which would be an error) or some other type (which would be a success). But surely there has got to be an easier way - what am I missing? (I have created my own StatusService on the server, I have thrown my own exception, but no joy). Thanks in advance for any hep - and thanks to Tim P for collecting all the links in the thread above - but those weren't enough for me to work around the problem. RB Bjorn Roche Reply | Threaded Open this post in threaded view ♦ ♦ | Report Content as Inappropriate ♦ ♦ Re: Handling exceptions/errors when using Restlet for Client and Server.... I can't help you directly, but I can say that I use restlet server (but not client) and I am pretty sure I DON'T have this problem. Is this a bug in the clien