I'm writing a REST web app (NetBeans 6.9, JAX-RS, TopLink Essentials) and trying to return JSON and HTTP status code. I have code ready and working that returns JSON when the HTTP GET method is called from the client. Essentially:
#Path("get/id")
#GET
#Produces("application/json")
public M_機械 getMachineToUpdate(#PathParam("id") String id) {
// some code to return JSON ...
return myJson;
}
But I also want to return an HTTP status code (500, 200, 204, etc.) along with the JSON data.
I tried to use HttpServletResponse:
response.sendError("error message", 500);
But this made the browser think it's a "real" 500 so the output web page was a regular HTTP 500 error page.
I want to return an HTTP status code so that my client-side JavaScript can handle some logic depending on it (to e.g. display the error code and message on an HTML page). Is this possible or should HTTP status codes not be used for such thing?
Here's an example:
#GET
#Path("retrieve/{uuid}")
public Response retrieveSomething(#PathParam("uuid") String uuid) {
if(uuid == null || uuid.trim().length() == 0) {
return Response.serverError().entity("UUID cannot be blank").build();
}
Entity entity = service.getById(uuid);
if(entity == null) {
return Response.status(Response.Status.NOT_FOUND).entity("Entity not found for UUID: " + uuid).build();
}
String json = //convert entity to json
return Response.ok(json, MediaType.APPLICATION_JSON).build();
}
Take a look at the Response class.
Note that you should always specify a content type, especially if you are passing multiple content types, but if every message will be represented as JSON, you can just annotate the method with #Produces("application/json")
There are several use cases for setting HTTP status codes in a REST web service, and at least one was not sufficiently documented in the existing answers (i.e. when you are using auto-magical JSON/XML serialization using JAXB, and you want to return an object to be serialized, but also a status code different than the default 200).
So let me try and enumerate the different use cases and the solutions for each one:
1. Error code (500, 404,...)
The most common use case when you want to return a status code different than 200 OK is when an error occurs.
For example:
an entity is requested but it doesn't exist (404)
the request is semantically incorrect (400)
the user is not authorized (401)
there is a problem with the database connection (500)
etc..
a) Throw an exception
In that case, I think that the cleanest way to handle the problem is to throw an exception. This exception will be handled by an ExceptionMapper, that will translate the exception into a response with the appropriate error code.
You can use the default ExceptionMapper that comes pre-configured with Jersey (and I guess it's the same with other implementations) and throw any of the existing sub-classes of javax.ws.rs.WebApplicationException. These are pre-defined exception types that are pre-mapped to different error codes, for example:
BadRequestException (400)
InternalServerErrorException (500)
NotFoundException (404)
Etc. You can find the list here: API
Alternatively, you can define your own custom exceptions and ExceptionMapper classes, and add these mappers to Jersey by the mean of the #Provider annotation (source of this example):
public class MyApplicationException extends Exception implements Serializable
{
private static final long serialVersionUID = 1L;
public MyApplicationException() {
super();
}
public MyApplicationException(String msg) {
super(msg);
}
public MyApplicationException(String msg, Exception e) {
super(msg, e);
}
}
Provider :
#Provider
public class MyApplicationExceptionHandler implements ExceptionMapper<MyApplicationException>
{
#Override
public Response toResponse(MyApplicationException exception)
{
return Response.status(Status.BAD_REQUEST).entity(exception.getMessage()).build();
}
}
Note: you can also write ExceptionMappers for existing exception types that you use.
b) Use the Response builder
Another way to set a status code is to use a Response builder to build a response with the intended code.
In that case, your method's return type must be javax.ws.rs.core.Response. This is described in various other responses such as hisdrewness' accepted answer and looks like this :
#GET
#Path("myresource({id}")
public Response retrieveSomething(#PathParam("id") String id) {
...
Entity entity = service.getById(uuid);
if(entity == null) {
return Response.status(Response.Status.NOT_FOUND).entity("Resource not found for ID: " + uuid).build();
}
...
}
2. Success, but not 200
Another case when you want to set the return status is when the operation was successful, but you want to return a success code different than 200, along with the content that you return in the body.
A frequent use case is when you create a new entity (POST request) and want to return info about this new entity or maybe the entity itself, together with a 201 Created status code.
One approach is to use the response object just like described above and set the body of the request yourself. However, by doing this you loose the ability to use the automatic serialization to XML or JSON provided by JAXB.
This is the original method returning an entity object that will be serialized to JSON by JAXB:
#Path("/")
#POST
#Consumes({ MediaType.APPLICATION_JSON })
#Produces({ MediaType.APPLICATION_JSON })
public User addUser(User user){
User newuser = ... do something like DB insert ...
return newuser;
}
This will return a JSON representation of the newly created user, but the return status will be 200, not 201.
Now the problem is if I want to use the Response builder to set the return code, I have to return a Response object in my method. How do I still return the User object to be serialized?
a) Set the code on the servlet response
One approach to solve this is to obtain a servlet request object and set the response code manually ourselves, like demonstrated in Garett Wilson's answer :
#Path("/")
#POST
#Consumes({ MediaType.APPLICATION_JSON })
#Produces({ MediaType.APPLICATION_JSON })
public User addUser(User user, #Context final HttpServletResponse response){
User newUser = ...
//set HTTP code to "201 Created"
response.setStatus(HttpServletResponse.SC_CREATED);
try {
response.flushBuffer();
}catch(Exception e){}
return newUser;
}
The method still returns an entity object and the status code will be 201.
Note that to make it work, I had to flush the response. This is an unpleasant resurgence of low-level Servlet API code in our nice JAX_RS resource, and much worse, it causes the headers to be unmodifiable after this because they were already sent on the wire.
b) Use the response object with the entity
The best solution, in that case, is to use the Response object and set the entity to be serialized on this response object. It would be nice to make the Response object generic to indicate the type of the payload entity in that case, but is not the currently the case.
#Path("/")
#POST
#Consumes({ MediaType.APPLICATION_JSON })
#Produces({ MediaType.APPLICATION_JSON })
public Response addUser(User user){
User newUser = ...
return Response.created(hateoas.buildLinkUri(newUser, "entity")).entity(restResponse).build();
}
In that case, we use the created method of the Response builder class in order to set the status code to 201. We pass the entity object (user) to the response via the entity() method.
The result is that the HTTP code is 401 as we wanted, and the body of the response is the exact same JSON as we had before when we just returned the User object. It also adds a location header.
The Response class has a number of builder method for different statuses (stati ?) such as :
Response.accepted()
Response.ok()
Response.noContent()
Response.notAcceptable()
NB: the hateoas object is a helper class that I developed to help generate resources URIs. You will need to come up with your own mechanism here ;)
That's about it.
I hope this lengthy response helps somebody :)
The answer by hisdrewness will work, but it modifies the whole approach to letting a provider such as Jackson+JAXB automatically convert your returned object to some output format such as JSON. Inspired by an Apache CXF post (which uses a CXF-specific class) I've found one way to set the response code that should work in any JAX-RS implementation: inject an HttpServletResponse context and manually set the response code. For example, here is how to set the response code to CREATED when appropriate.
#Path("/foos/{fooId}")
#PUT
#Consumes("application/json")
#Produces("application/json")
public Foo setFoo(#PathParam("fooID") final String fooID, final Foo foo, #Context final HttpServletResponse response)
{
//TODO store foo in persistent storage
if(itemDidNotExistBefore) //return 201 only if new object; TODO app-specific logic
{
response.setStatus(Response.Status.CREATED.getStatusCode());
}
return foo; //TODO get latest foo from storage if needed
}
Improvement: After finding another related answer, I learned that one can inject the HttpServletResponse as a member variable, even for singleton service class (at least in RESTEasy)!! This is a much better approach than polluting the API with implementation details. It would look like this:
#Context //injected response proxy supporting multiple threads
private HttpServletResponse response;
#Path("/foos/{fooId}")
#PUT
#Consumes("application/json")
#Produces("application/json")
public Foo setFoo(#PathParam("fooID") final String fooID, final Foo foo)
{
//TODO store foo in persistent storage
if(itemDidNotExistBefore) //return 201 only if new object; TODO app-specific logic
{
response.setStatus(Response.Status.CREATED.getStatusCode());
}
return foo; //TODO get latest foo from storage if needed
}
If you like to keep your resource layer clean of Response objects, then I recommend you use #NameBinding and binding to implementations of ContainerResponseFilter.
Here's the meat of the annotation:
package my.webservice.annotations.status;
import javax.ws.rs.NameBinding;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
#NameBinding
#Retention(RetentionPolicy.RUNTIME)
public #interface Status {
int CREATED = 201;
int value();
}
Here's the meat of the filter:
package my.webservice.interceptors.status;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerResponseContext;
import javax.ws.rs.container.ContainerResponseFilter;
import javax.ws.rs.ext.Provider;
import java.io.IOException;
#Provider
public class StatusFilter implements ContainerResponseFilter {
#Override
public void filter(ContainerRequestContext containerRequestContext, ContainerResponseContext containerResponseContext) throws IOException {
if (containerResponseContext.getStatus() == 200) {
for (Annotation annotation : containerResponseContext.getEntityAnnotations()) {
if(annotation instanceof Status){
containerResponseContext.setStatus(((Status) annotation).value());
break;
}
}
}
}
}
And then the implementation on your resource simply becomes:
package my.webservice.resources;
import my.webservice.annotations.status.StatusCreated;
import javax.ws.rs.*;
#Path("/my-resource-path")
public class MyResource{
#POST
#Status(Status.CREATED)
public boolean create(){
return true;
}
}
I found it very useful to build also a json message with repeated code, like this:
#POST
#Consumes("application/json")
#Produces("application/json")
public Response authUser(JsonObject authData) {
String email = authData.getString("email");
String password = authData.getString("password");
JSONObject json = new JSONObject();
if (email.equalsIgnoreCase(user.getEmail()) && password.equalsIgnoreCase(user.getPassword())) {
json.put("status", "success");
json.put("code", Response.Status.OK.getStatusCode());
json.put("message", "User " + authData.getString("email") + " authenticated.");
return Response.ok(json.toString()).build();
} else {
json.put("status", "error");
json.put("code", Response.Status.NOT_FOUND.getStatusCode());
json.put("message", "User " + authData.getString("email") + " not found.");
return Response.status(Response.Status.NOT_FOUND).entity(json.toString()).build();
}
}
In case you want to change the status code because of an exception, with JAX-RS 2.0 you can implement an ExceptionMapper like this. This handles this kind of exception for the whole app.
#Provider
public class UnauthorizedExceptionMapper implements ExceptionMapper<EJBAccessException> {
#Override
public Response toResponse(EJBAccessException exception) {
return Response.status(Response.Status.UNAUTHORIZED.getStatusCode()).build();
}
}
If your WS-RS needs raise an error why not just use the WebApplicationException?
#GET
#Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
#Path("{id}")
public MyEntity getFoo(#PathParam("id") long id, #QueryParam("lang")long idLanguage) {
if (idLanguage== 0){
// No URL parameter idLanguage was sent
ResponseBuilder builder = Response.status(Response.Status.BAD_REQUEST);
builder.entity("Missing idLanguage parameter on request");
Response response = builder.build();
throw new WebApplicationException(response);
}
... //other stuff to return my entity
return myEntity;
}
JAX-RS has support for standard/custom HTTP codes. See ResponseBuilder and ResponseStatus, for example:
http://jackson.codehaus.org/javadoc/jax-rs/1.0/javax/ws/rs/core/Response.ResponseBuilder.html#status%28javax.ws.rs.core.Response.Status%29
Keep in mind that JSON information is more about the data associated with the resource/application. The HTTP codes are more about the status of the CRUD operation being requested. (at least that is how it's supposed to be in REST-ful systems)
Please look at the example here, it best illustrates the problem and how it is solved in the latest (2.3.1) version of Jersey.
https://jersey.java.net/documentation/latest/representations.html#d0e3586
It basically involves defining a custom Exception and keeping the return type as the entity. When there is an error, the exception is thrown, otherwise, you return the POJO.
I'm not using JAX-RS, but I've got a similar scenario where I use:
response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
Also, notice that by default Jersey will override the response body in case of an http code 400 or more.
In order to get your specified entity as the response body, try to add the following init-param to your Jersey in your web.xml configuration file :
<init-param>
<!-- used to overwrite default 4xx state pages -->
<param-name>jersey.config.server.response.setStatusOverSendError</param-name>
<param-value>true</param-value>
</init-param>
The following code worked for me. Injecting the messageContext via annotated setter and setting the status code in my "add" method.
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import org.apache.cxf.jaxrs.ext.MessageContext;
public class FlightReservationService {
MessageContext messageContext;
private final Map<Long, FlightReservation> flightReservations = new HashMap<>();
#Context
public void setMessageContext(MessageContext messageContext) {
this.messageContext = messageContext;
}
#Override
public Collection<FlightReservation> list() {
return flightReservations.values();
}
#Path("/{id}")
#Produces("application/json")
#GET
public FlightReservation get(Long id) {
return flightReservations.get(id);
}
#Path("/")
#Consumes("application/json")
#Produces("application/json")
#POST
public void add(FlightReservation booking) {
messageContext.getHttpServletResponse().setStatus(Response.Status.CREATED.getStatusCode());
flightReservations.put(booking.getId(), booking);
}
#Path("/")
#Consumes("application/json")
#PUT
public void update(FlightReservation booking) {
flightReservations.remove(booking.getId());
flightReservations.put(booking.getId(), booking);
}
#Path("/{id}")
#DELETE
public void remove(Long id) {
flightReservations.remove(id);
}
}
Expanding on the answer of Nthalk with Microprofile OpenAPI you can align the return code with your documentation using #APIResponse annotation.
This allows tagging a JAX-RS method like
#GET
#APIResponse(responseCode = "204")
public Resource getResource(ResourceRequest request)
You can parse this standardized annotation with a ContainerResponseFilter
#Provider
public class StatusFilter implements ContainerResponseFilter {
#Override
public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext) {
if (responseContext.getStatus() == 200) {
for (final var annotation : responseContext.getEntityAnnotations()) {
if (annotation instanceof APIResponse response) {
final var rawCode = response.responseCode();
final var statusCode = Integer.parseInt(rawCode);
responseContext.setStatus(statusCode);
}
}
}
}
}
A caveat occurs when you put multiple annotations on your method like
#APIResponse(responseCode = "201", description = "first use case")
#APIResponse(responseCode = "204", description = "because you can")
public Resource getResource(ResourceRequest request)
I'm using jersey 2.0 with message body readers and writers. I had my method return type as a specific entity which was also used in the implementation of the message body writer and i was returning the same pojo, a SkuListDTO.
#GET
#Consumes({"application/xml", "application/json"})
#Produces({"application/xml", "application/json"})
#Path("/skuResync")
public SkuResultListDTO getSkuData()
....
return SkuResultListDTO;
all i changed was this, I left the writer implementation alone and it still worked.
public Response getSkuData()
...
return Response.status(Response.Status.FORBIDDEN).entity(dfCoreResultListDTO).build();
I have an object with state and non-serializable fields, like threads, and I would to invoke functions on it like one would do it through RMI but through http. I don't want to scale and I am in an isolated network. I am currently using Jetty, like this:
public class ObjectHandler extends AbstractHandler {
MyStatefulObject obj;
public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
String action = request.getParameter("action");
switch (action) {
case "method1":
obj.method1(request.getParameter("some-parameter"));
break;
case "method2":
obj.method2(request.getParameter("some-other-parameter"));
break;
}
baseRequest.setHandled(true);
}
}
which is kind of weird. I would like to use something like Servlets, and use the different methods to tell apart the action to do, or use JAX-RS to use the calling url to tell apart the action to do. But both of those methods are stateless, that is, I cannot pass an object to a servlet, and, at least with jersey, the construction was made with the class, not with and instance of it, so I could not control the construction of the MyStatefulObject object. So, is there a library for, let's say, annotate an object and pass it to a server instance and start listening to requests? I would like to make something like this:
#Path("/")
public class MyStatefulObject {
MyStatefulObject(Parameter param1, Param) {
//some building stuff
}
#POST
#Path("/path1")
#Consumes(MediaType.MULTIPART_FORM_DATA)
#Produces(MediaType.APPLICATION_JSON + "; charset=UTF-8")
void method1(Parameter param) {}
#POST
#Path("/path2")
#Consumes(MediaType.MULTIPART_FORM_DATA)
#Produces(MediaType.APPLICATION_JSON + "; charset=UTF-8")
Object method2(Parameter param) {
return new Object();
}
}
while outside I would have:
Server server = new Server(8081);
server.setHandler(new MyStatefulObject(param));
server.start();
server.join();
Is there a library that makes me able to do that? as I say before, I don't want to scale (this is running in a small network) and there is no security concerns. I just want to "publish" an object.
In the end, Jersey does allow stateful objects to be published, using the ResourceConfig class with an object (as opposed with a Class, which is the use I found more frequently). Funny cause in this question they want to do the exact opposite. We simply register an object in the ResourceConfig.
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;
import java.net.URI;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.glassfish.jersey.jetty.JettyHttpContainerFactory;
import org.glassfish.jersey.server.ResourceConfig;
import javax.inject.Singleton;
#Path("calculator")
public class Calculator {
int i = -1;
public Calculator(int i) {
this.i = i;
}
#GET
#Path("increment")
#Produces(MediaType.APPLICATION_JSON)
public String increment() {
i = i + 1;
return "" + i;
}
public static void main(String[] args) throws Exception {
ResourceConfig resourceConfig = new ResourceConfig();
resourceConfig.register(new Calculator(10));
Server server = JettyHttpContainerFactory.createServer(new URI("http://localhost:8080"), resourceConfig);
server.start();
}
}
I am working on Rest web services and client using CXF 3.1.2 , and i have few clarification as below,
Service:
import javax.jws.WebService;
import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
public class GenServiceImpl {
#GET
#Produces(MediaType.TEXT_PLAIN)
#Consumes(MediaType.TEXT_PLAIN)
#Path("/agentLogin/{ext}")
public String agentLogin(#PathParam("ext") Integer ext) {
return "EventAgentLoggedIn";
}
#POST
#Produces(MediaType.TEXT_PLAIN)
#Consumes({"application/xml", MediaType.TEXT_PLAIN})
#Path("/agentLogout")
public String agentLogout(String ext) {
return "EventAgentLoggedOut";
}
}
Client:
import javax.ws.rs.core.Response;
import org.apache.cxf.jaxrs.client.WebClient;
public class TestClient {
static final String REST_URI = "http://localhost:8080/RestfulSample/Restful";
public static void main(String[] args) {
WebClient client = WebClient.create(REST_URI);
//Get
client.path("agentLogin").path(new Integer(1234)).accept(MediaType.TEXT_PLAIN);
String agentLoginResponse = client.get(String.class);
System.out.println(agentLoginResponse);
client.reset();
//Post
client.path("agentLogout").accept(MediaType.TEXT_PLAIN);
Response agentLogoutResponse = client.post("10245");
System.out.println(agentLogoutResponse.readEntity(String.class));
client.reset();
}
Clarifications:
In my above example - In service class Post method(agentLogout) , i am getting error if i replace #Consumes({"application/xml", MediaType.TEXT_PLAIN})
with
#Consumes(MediaType.TEXT_PLAIN) whereas it works fine in Get method(agentLogin), may i know why it is so?
It is right to use client.reset(); - Here i am trying to use single WebClient to access all my methods.
Could you please let me know what i tried in my example is best practice ? and it will be appreciated if you could correct me here
Thanks,
Here are the clarifications.
Set content type to text/plain while posting. And you can set in your servers side class #Consumes(MediaType.TEXT_PLAIN)
client.replaceHeader("Content-Type",MediaType.TEXT_PLAIN);
Yes you can use rest method, here is java doc
When reusing the same WebClient instance for multiple invocations,
one may want to reset its state with the help of the reset() method,
for example, when the Accept header value needs to be changed and the
current URI needs to be reset to the baseURI (as an alternative to a
back(true) call). The resetQuery() method may be used to reset the
query values only. Both options are available for proxies too.
I would prefer to use proxy and access REST more like OOPS.
You could create interface for the above server class(Generally I careate REST definition as interface and then implement the interface( more like SOAP way)), which could be auto generated using WADLToJava maven plugin from WADL.
Here is sample interface for above server side rest class
public interface GenService {
#GET
#Produces(MediaType.TEXT_PLAIN)
#Consumes(MediaType.TEXT_PLAIN)
#Path("/agentLogin/{ext}")
public String agentLogin(#PathParam("ext") Integer ext);
#POST
#Produces(MediaType.TEXT_PLAIN)
#Consumes(MediaType.TEXT_PLAIN)
#Path("/agentLogout")
public String agentLogout(String ext);
}
Since you are not using spring , I will create a singleton class
public class CxfRestSingleton {
public static GenService obj;
public static GenService getInstance() {
if (obj == null) {
obj = JAXRSClientFactory.create("http://localhost:8080/RestfulSample/Restful", GenService.class);
}
return obj;
}
}
And you can access the rest using below code.
public static void main( String[] args )
{
System.out.println( CxfRestSingleton.getInstance().agentLogin(12345));
}
I have this resource (simplified):
#Path("/cars{extension:(\\.(xml|json))?}")
public class Cars {
#GET
#Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public Response searchCars(#PathParam("extension") String extension) {
System.out.println("extension: " + extension);
//...
return Response.status(200).entity(output).build();
}
}
And I want, for instance (but the business logic can change), to return an xml response if the extension is xml, or Json if the extension is json, whatever the header "Accept" is.
The thing is by default I want to use the Accept header but let's say some dummy guy wants to access my web service with Ajax and doesn't know much about headers, I want to make things easy for him by just adding the appropriate extension.
With that snippet I am able to get the extension (if there is one) but I don't know how to change the strategy accordingly.
Thanks!
EDIT:
So I found something, I can use .type() from Response.ResponseBuilder like:
Response.ResponseBuilder responseBuilder = Response.status(200).entity(output);
if ([some test about extention or header])
responseBuilder.type(MediaType.APPLICATION_XML);
// other tests
I don't know if this is the correct way to do, but that would mean I need to handle it for all the paths...
I would use a ContainerResponseFilter for this, so you don't have todo it for each path.
First check for extension - aka the MediaType the dummy guy loves to get.
Than check if requested MediaType is acceptable for your service. If not, I would say the dummy guy has hard luck ;)
Example code [jersey 2.x]:
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.util.List;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerResponseContext;
import javax.ws.rs.container.ContainerResponseFilter;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.Provider;
#Provider
public class EntityResponseFilter implements ContainerResponseFilter {
#Override
public void filter( ContainerRequestContext reqc , ContainerResponseContext resc ) throws IOException {
MediaType mediaType = this.getMediaTypeFromExtentionOrHeader(); // TODO
List<MediaType> mediaTypes = reqc.getAcceptableMediaTypes();
if( mediaTypes.contains(mediaType) ) {
resc.setEntity( resc.getEntity(), new Annotation[0], mediaType );
}
// ...
}
}
Hope this was helpful somehow :)
Hi i am new to Rest Service in Java. First i want to explain my problem and then at the end i will be asking question.
I am using Mozilla rest CLIENT. My rest class looks like:
#Path("/api1")
public class RestService {
#POST
#Path("/v1")
#Consumes("application/json")
#Produces("application/json")
public String v1(String json){
//Some code here
}
#POST
#Path("/v2")
#Consumes("application/json")
#Produces("application/json")
public String v2(String json){
//Some code here
}
}
Now in this code i have two functions.
To access v1, call will be:
http://localhost:8080/project_name/package/api1/v1
To access v2 call will be:
http://localhost:8080/project_name/package/api1/v2
Question:
Now in my rest service class i want to add a patch of code which detects that whether any function which has been called either v1,v2 or v3 exists in this service or not?
Can i do this? Or anyother way to do this?
Thanks
Well, you could add a wildcard response:
#POST
#Path("/{what}")
#Consumes("application/json")
#Produces("application/json")
public String v2(String json, #PathParameter("what") String what){
return "The path "+what+" does not exist.";
}
However, since the user will never see the direct responses, you can answer with a customized 404:
#POST
#Path("/{what}")
#Consumes("application/json")
#Produces("application/json")
public Response v2(String json, #PathParameter("what") String what){
return Response.status(Status.NOT_FOUND).entity("The path "+what+" does not exist.");
}
This way you can also detect on the client side when something is incorrect.
The best approach for you is to add a fallback response. That will be called when somebody tries to access any non existing WS method.
#RequestMapping(value = {"*"})
public String getFallback()
{
return "This is a fallback response!";
}