Change Spring Data REST exposing link - rest

By default, Spring Data REST will expose search resources to urls under {resource_name}/search. For example, findBySubject_Id in the following code will be exposed to {baseUrl}/questions/search/findBySubject_Id?subjectId={subjectId}.
public interface QuestionRepository extends PagingAndSortingRepository<Question, String> {
Page<Question> findBySubject_Id(#Param("subjectId")String subjectId, Pageable pageable);
}
For compatiblility reasons, I need the exposing link to be {baseUrl}/questions?subjectId={subjectId}. Is there any way to do it?

You can not override /search url. If you really need a link without search, you should override response handler for the entity via writing your own controller with annotation #RepositoryRestController

Related

Renaming an XML/SOAP tag using Apache CXF

I've got a SOAP web-service server using Apache CXF as implementation. Due to some external technical constraint I'd like to be able to rename some XML tags naming an operation parameter (which are deprecated) in the inbound SOAP request. I was reading about using Interceptors for this, but the documentation on how to setup/configure them is not very clear.
My code to publish an endpoint is the following:
Endpoint endpoint = Endpoint.create(
"http://schemas.xmlsoap.org/soap/", new MyServer());
endpoint.publish("ws/endpoint");
Ideally I'd like to add a filter only to a given endpoint (I have several of them).
Apache's documentations about interceptors are quite clear (IMO), anyway, there is a helloworld project (based on spring boot, cxf and maven) in my github profile which you can take a look for setting up interceptors (in fact it's a baisc autentication interceptor).
For setting up an interceptor (e.g InInterceptor), your class should extend AbstractPhaseInterceptor<Message> and override handleMessage(Message message) method, then in the constructor you should declare the phase in which the interceptor is going to be applied. Finally you have to instantiate it and apply in on an Endpoint.
As you said:
rename some XML tags naming an operation parameter (which are
deprecated) in the inbound SOAP request
I think the name of the operation parameter (in WSDL file) is something different from the argument of your web method. Suppose that there is method in your endpoint named addPerson:
#WebMethod
String addPerson(Person person) {
/*method logic*/
}
and Person class:
class Person {
private String firstName;
private String lastName;
private Date birthDate;
//getters and setters
}
in order to map lastName property to a different name, you have to annotate it with
#XmlElement(name = "sureName")
private String lastName;
after applying this anotation, sureName (in wsdl file) is going to be mapped to lastName.
In addition, there is #WebParam annotation which can be used for changing the name of web method arguments:
#WebMethod
String sayHello( #WebParam(name = "sureName") String lastName);
Hope it helps.

Controller return type and httpStatus best practice and production/consumption on method in REST WS

I commence in REST and I have some questions:
What type must the controller return? Typically, I'm asking if my Rest #Controller must return Item object as it is or encapsulate it in ResponseEntity in order to specify http-status-code.
What http status code to use in a GET method on a particular item ("/items/2") if the given item does not exists: HttpMediaStatus.OK(200) and null return or HttpStatus.NO_CONTENT(204) and null return ?
Second part: I saw it was possible to specify #Produces and #Consumes on WS method but what the use of that? My application and my methods work so, why specify MediaType.APPLICATION_JSON_VALUE? Doesn't Spring/SpringBoot automatically convert Item or ResponseEntity into json?
Context: using Spring Boot, hibernate, REST webservice.
Thank you.
Many questions in one, I'll provide short answers with a bunch of link to relevant articles and the reference documentation.
What type must the controller return?
Depends on your annotation and the RESTful-ness of your service. There are three annotations you can use for controllers: #Controller, #RestController and #RepositoryRestController.
Controller is the base annotation to mark your class as a controller. The return type of the controller endpoint methods can be many things, I invite you to read this dedicated post to get a grasp of it.
When developing a pure-REST service, you will focus on using RestController and RepositoryRestController.
RestControlleris Controller + ResponseBody. It binds the return value of the endpoint method to the web response body:
#RestController
public ItemController {
#RequestMapping("/items/{id}")
public Item getItem(#PathVariable("id") String id) {
Item item = ...
return item;
}
}
With this, when you hit http:/.../api/items/foo, Spring does its magic, automatically converting the item to a ResponseEntity with a relevant 40X status code and some default HTTP headers.
At some point, you will need more control over the status code and headers, while still benefiting from Spring Data REST's settings. That's when you will use RepositoryRestController with a ResponseEntity<Item> as return type, see the example the Spring Data REST reference.
What http status code to use in a GET method on a particular item if the given item does not exists?
Bluntly said: use HttpStatus.NOT_FOUND. You're looking for a resource that does not exist, there's something wrong.
That being said, it is completely up to you to decide how to handle missing resources in your project. If your workflow justifies it, a missing resource could be something completely acceptable that indeed returns a 20X response, though you may expect users of your API to get confused if you haven't warned them or provided some documentation (we are creatures of habits and conventions). But I'd still start with a 404 status code.
(...) #Produces and #Consumes on WS method but what the use of that? My application and my methods work so, why specify MediaType.APPLICATION_JSON_VALUE? Doesn't Spring/SpringBoot automatically convert Item or ResponseEntity into json?
#Consumes and #Produces are respectively matched against content-type and accept headers from the request. It's a mean of restricting the input accepted and the output provided by your endpoint method.
Since we're talking about a REST service, communications between clients of the API and the service are expected to be JSON-formatted. Thanks to Spring HATEOAS, the answer are actually formatted with the application/hal+json content-type.
In that scenario, you can indeed not bother with those two annotations. You will need them if you develop a service that accepts different content-types (application/text, application/json, application/xml...) and provides, for instance, HTML views to users of your website and JSON or XML response to automated clients of your service.
For real life examples:
Facebook provides the Graph API for applications to read to/write from its graph, while users happily (?) surf on web pages
Google does the same with the Google Maps API

Performing Explicit Route Mapping based upon Web Api v2 Attributes

I'm upgrading a custom solution where I can dynamically register and unregister Web Api controllers to use the new attribute routing mechanism. However, it seems to recent update to RTM break my solution.
My solution exposes a couple of Web Api controllers for administration purposes. These are registered using the new HttpConfigurationExtensions.MapHttpAttributeRoutes method call.
The solution also allows Web Api controllers to be hosted in third-party assemblies and registered dynamically. At this stage, calling HttpConfigurationExtensions.MapHttAttributeRoutes a second time once the third-party controller is loaded would raise an exception. Therefore, my solution uses reflection to inspect the RoutePrefix and Route attributes and register corresponding routes on the HttpConfiguration object.
Unfortunately, calling the Web Api results in the following error:
"No HTTP resource was found that matches the request URI".
Here is a simple controller that I want to use:
[RoutePrefix("api/ze")]
public sealed class ZeController : ApiController
{
[HttpGet]
[Route("one")]
public string GetOne()
{
return "One";
}
[HttpGet]
[Route("two")]
public string GetTwo()
{
return "Two";
}
[HttpPost]
[Route("one")]
public string SetOne(string value)
{
return String.Empty;
}
}
Here is the first solution I tried:
configuration.Routes.MapHttpRoute("ZeApi", "api/ze/{action}");
Here is the second solution I tried:
var type = typeof(ZeController);
var routeMembers = type.GetMethods().Where(m => m.IsPublic);
foreach (MethodInfo method in routeMembers)
{
var routeAttribute = method.GetCustomAttributes(false).OfType<RouteAttribute>().FirstOrDefault();
if (routeAttribute != null)
{
string controllerName = type.Name.Substring(0, type.Name.LastIndexOf("Controller"));
string routeTemplate = string.Join("/", "api/Ze", routeAttribute.Template);
configuration.Routes.MapHttpRoute(method.Name, routeTemplate);
}
}
I also have tried a third solution, whereby I create custom classes that implement IHttpRoute and trying to register them with the configuration to no avail.
Is it possible to use legacy-style route mapping based upon the information contained in the new routing attributes ?
Update
I have installed my controller in a Web Application in order to troubleshoot the routing selection process with the Web Api Route Debugger. Here is the result of the screenshot:
As you can see, the correct action seems to be selected, but I still get a 404 error.
Update2
After further analysis, and per Kiran Challa's comment below, it seems that the design of Web Api prevents mixing attribute routing and conventional routing, and that what I want to do is not possible using this approach.
I have created a custom attribute [RouteEx] that serves the same purpose of the Web Api [Route] attribute, and now my code works perfectly.
I guess, since this is not possible using the conventional attribute routing, none of the answers on this question could legitimately be consisered valid. So I'm not nominating an answer just yet.
You shouldn't be required to use reflection and inspect the attribute-routing based attributes yourself. Attribute routing uses existing Web API features to get list of controllers to scan through.
Question: Before the switch to attribute routing, how were you loading these assemblies having the
controllers?
If you were doing this by IAssembliesResolver service, then this solution should work even with attribute routing and you should not be needing to do anything extra.
Regarding your Update: are you calling MapHttpAttributeRoutes?

Difference between redirect:prefix and forward:prefix in Spring MVC3.0

Hi I am new to Spring MVC i am following Spring reference documentaion I have doubt in view resolver. Here is my sample code.
#Controller
#RequestMapping("/form")
public class MyController {
#RequestMapping(method = RequestMethod.GET)
public String setupForm() {
// do my stuff
return "myform";
}
#RequestMapping(method = RequestMethod.POST)
public String processForm(ModelMap model) {
// process form data
model.addAttribute("notification", "Successfully did it!");
return "redirect:/form";
}
}
here i am using two controllers, the first one returns "myform" and second one returns "redirect:/form". My question is, what is the difference between these two and how it works?
If you are familiar with jsp servlet, I think you can know the difference between redirect and forward, or you can get tons of answers from google. Then I want to explain a bit about how Spring does this. in setupForm method, it returns myform, then according to your view resovler configuration, it will try to find a myform.jsp or another likes this, and if your view resovler is internalresourceviewresovler, Spring will do a forward automatically and try to find this jsp in web-inf directory, if not, you have to specify a forward prefix. and for processForm method, that after return redirect:/form, it will force browser to send a new request /form to server which can be got by spring mvc and it will handle it with the related method.

RESTful using Jersey: method to POST multiple entities

I am trying to develop a method in my RESTful web service in Java to insert multiple entries into a MySQL DB using POST request. The generated RESTful Web Service has a method to insert a single entity, but not multiple ones. For example, it accepts:
<creature>
<sort>Mouse</sort>
<name>Pinky</name>
</creature>
But not (what I would like):
<creature>
<sort>Mouse</sort>
<name>Pinky</name>
</creature>
<creature>
<sort>Elephant</sort>
<name>Dumbo</name>
</creature>
I'm guessing that you have to loop through the entities, but not sure how to implement it, being a shameful novice.
Just ran into this myself. I need transactional posts of multiple items, so iterating on the client is out of the question. The consensus seems to be that you need to use a separate path from your normal resources:
http://chasenlehara.com/blog/creating-restful-web-services/ (Multi-resources)
RESTful way to create multiple items in one request
I couldn't find much about how to do this with Jersey, though. As it turns out, it's pretty easy. You should already have multi-entity converter and resource classes for GET requests, you just need to specify a path where the server can assume it's going to receive them:
#Path("creatures")
#Stateless
public class CreaturesResource {
...
#POST
#Consumes({"application/xml", "application/json"})
public Response post(CreatureConverter data) {
Creature entity = data.resolveEntity(em);
postCreature(entity);
}
#POST #Path("multi")
#Consumes({"application/xml", "application/json"})
public Response postMulti(CreaturesConverter data) {
Collection<Creature> entities = data.getEntities();
for (Creature c : entities) {
postCreature(c);
}
}
Then instead of posting
<creature />
to
http://.../resources/creatures
You would post
<creatures>
<creature />
<creature />
</creatures>
to
http://.../resources/creatures/multi