CompletableFuture: control http response status-codes - spring-mvc

I'm currently struggeling returning http response status-codes on certain conditions. Let's say, the return objetct of taskService.getNewTasks is null. In this case I want to return status-code 404. On some exception I want to return some 50x, and so on.
My code so far
#RestController
public class TaskController {
#Autowired
private TaskService taskService;
#GetMapping(path = "gettasks")
private Future<Tasks> getNewTasks() {
return taskService.getNewTasks();
}
...
}
#Service
public class TaskService {
#Async
public Future<Tasks> getNewTasks() {
...
return CompletableFuture.completedFuture(tasks);
}
}

This could suit you.
#GetMapping(path = "gettasks")
private CompletableFuture<ResponseEntity<Tasks>> getNewTasks() {
CompletableFuture<Tasks> future = new CompletableFuture<>();
future.complete(taskService.getNewTasks());
if(yourCondition){
return future.thenApply(result -> new ResponseEntity<Tasks>(result, HttpStatus.STATUS_1));
}
return future.thenApply(result -> new ResponseEntity<Tasks>(result, HttpStatus.STATUS_2));
}

As described in https://docs.spring.io/spring/docs/current/spring-framework-reference/web.html#mvc-ann-return-types, Future isn’t supported as return type for controller handler methods.
Since you’re using CompletableFuture you can just return that or CompletionStage, which are supported by spring.
If that completes with an exception, you can use the regular Spring exception handling mechanisms like annotating the exception with #ResponseStatus .

Related

Spring OAuth2 Making `state` param at least 32 characters long

I am attempting to authorize against an external identity provider. Everything seems setup fine, but I keep getting a validation error with my identity provider because the state parameter automatically tacked onto my authorization request is not long enough:
For example:
&state=uYG5DC
The requirements of my IDP say that this state param must be at least 32-characters long. How can I programmatically increase the size of this auto-generated number?
Even if I could generate this number myself, it is not possible to override with other methods I have seen suggested. The following attempt fails because my manual setting of ?state=abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz is superceded by the autogenerated param placed after it during the actual request:
#Bean
public OAuth2ProtectedResourceDetails loginGovOpenId() {
AuthorizationCodeResourceDetails details = new AuthorizationCodeResourceDetails() {
#Override
public String getUserAuthorizationUri() {
return super.getUserAuthorizationUri() + "?state=abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
}
};
details.setClientId(clientId);
details.setAccessTokenUri(accessTokenUri);
details.setUserAuthorizationUri(userAuthorizationUri);
details.setScope(Arrays.asList("openid", "email"));
details.setPreEstablishedRedirectUri(redirectUri);
details.setUseCurrentUri(true);
return details;
}
The 6-character setting seems to be set here, is there a way to override this?
https://github.com/spring-projects/spring-security-oauth/blob/master/spring-security-oauth2/src/main/java/org/springframework/security/oauth2/common/util/RandomValueStringGenerator.java
With the help of this post:
spring security StateKeyGenerator custom instance
I was able to come up with a working solution.
In my configuration class marked with these annotations:
#Configuration
#EnableOAuth2Client
I configured the following beans:
#Bean
public OAuth2ProtectedResourceDetails loginGovOpenId() {
AuthorizationCodeResourceDetails details = new AuthorizationCodeResourceDetails();
AuthorizationCodeResourceDetails details = new
details.setClientId(clientId);
details.setClientSecret(clientSecret);
details.setAccessTokenUri(accessTokenUri);
details.setUserAuthorizationUri(userAuthorizationUri);
details.setScope(Arrays.asList("openid", "email"));
details.setPreEstablishedRedirectUri(redirectUri);
details.setUseCurrentUri(true);
return details;
}
#Bean
public StateKeyGenerator stateKeyGenerator() {
return new CustomStateKeyGenerator();
}
#Bean
public AccessTokenProvider accessTokenProvider() {
AuthorizationCodeAccessTokenProvider accessTokenProvider = new AuthorizationCodeAccessTokenProvider();
accessTokenProvider.setStateKeyGenerator(stateKeyGenerator());
return accessTokenProvider;
}
#Bean
public OAuth2RestTemplate loginGovOpenIdTemplate(final OAuth2ClientContext clientContext) {
final OAuth2RestTemplate template = new OAuth2RestTemplate(loginGovOpenId(), clientContext);
template.setAccessTokenProvider(accessTokenProvider());
return template;
}
Where my CustomStateKeyGenerator implementation class looks as follows:
public class CustomStateKeyGenerator implements StateKeyGenerator {
// login.gov requires state to be at least 32-characters long
private static int length = 32;
private RandomValueStringGenerator generator = new RandomValueStringGenerator(length);
#Override
public String generateKey(OAuth2ProtectedResourceDetails resource) {
return generator.generate();
}
}

How to pass a generic collection Class object as an argument

I've RESTful service Spring MVC based.
The service has a RESTful resource method that returns the following response:
public class OperationalDataResponse<T> {
private String status;
private String statusMessage;
private T result;
//getters and setters
}
This response object encapsulates the result object of type T.
On the client side I use RestTemplate with GsonHttpMessageConverter added.
I get the response from service as a ResponseEntity
I handle the generic response with runtime Type as below:
public class OperationalDataRestClient<REQ,RESULT_TYPE> {
public OperationalDataResponse<RESULT_TYPE> getOperationalData(String resourcePath, Map<String, Object> urlVariables, Class<RESULT_TYPE> resultType) {
//code to invoke service and get data goes here
String responseString = responseEntity.getBody();
response = GsonHelper.getInstance().fromJson(responseString, getType(OperationalDataResponse.class, resultType));
}
Type getType(final Class<?> rawClass, final Class<?> parameter) {
return new ParameterizedType() {
#Override
public Type[] getActualTypeArguments() {
return new Type[] { parameter };
}
#Override
public Type getRawType() {
return rawClass;
}
#Override
public Type getOwnerType() {
return null;
}
};
}
}
This works like a charm as long as my resultType is a non-collection class.
So, this works great from caller code:
getOperationalData(someResourcePath, someUrlVariables, MyNonGenericClass.class)
However if my resultType is a collection (say, List<String> or List<MyNonGenericClass>)
then I don't know how to pass the resultType Class from the caller code.
For example, from caller code,
getOperationalData(someResourcePath, someUrlVariables, List.class)
or
getOperationalData(someResourcePath, someUrlVariables, List<MyNonGenericClass>.class)
throws compilation error.
I tried passing on ArrayList.class as well but that too doesn't work.
Any suggestion how can I pass a generic collection as a resultType from caller code (in other words, as an example, how can I pass the class object of a List<String> or List<MyNonGenericClass> from caller code ?)
If you know that ResultType is coming as a List, Then it will obvious fail like you said compilation issue.Why? because you are trying to send a List when you method only accepts a single value.In order to over come that issue you will have to change the method arguments to the following
public OperationalDataResponse<RESULT_TYPE> getOperationalData(String resourcePath, Map<String, Object> urlVariables, List<Class<RESULT_TYPE>> resultType){
....
}
and you will have to make some slight modification to getType() Method,loop it and then pass each class value to getType method like so
for(MyNonGenericClass myClass:mylist){
getType(OperationalDataResponse.class, myClass.getClass());
}

Mono: Return results from a long running method

Currently I'm beginnging with Spring + reactive programming. My aim is to return a result in a REST-endpoint from a long running method (polling on a database). I'm stuck on the api. I simply don't know how to return the result as Mono in my FooService.findFoo method.
#RestController
public class FooController {
#Autowired
private FooService fooService;
#GetMapping("/foo/{id}")
private Mono<ResponseEntity<Foo> findById(#PathVariable String id) {
return fooService.findFoo(id).map(foo -> ResponseEntity.ok(foo)) //
.defaultIfEmpty(ResponseEntity.notFound().build())
}
...
}
#Service
public class FooService {
public Mono<Foo> findFoo(String id) {
// this is the part where I'm stuck
// I want to return the results of the pollOnDatabase-method
}
private Foo pollOnDatabase(String id) {
// polling on database for a while
}
}
Use the Mono.fromSupplier method! :)
#Service
public class FooService {
public Mono<Foo> findFoo(String id) {
return Mono
.fromSupplier(() -> pollOnDatabase(id))
.subscribeOn(Schedulers.boundedElastic());
}
private Foo pollOnDatabase(String id) {
// polling on database for a while
}
}
With this method we return a Mono value ASAP, constant time with a supplier which will be evaluated on demand by the caller's subscribe. This is the non blocking way to call a long-running-blocking method.
BE AWARE that without subscription on boundedElastic the blocking pollOnDatabase method will block the original thread, which leads to thread starvation. You can find different schedules for every kind of tasks here.
DO NOT use Mono.just with long-running calculations as it will run the calculation before returning the Mono instance, thereby blocking the given thread.
+1: Watch this video to learn to avoid "reactor meltdown". Use some lib to detect blocking calls from non-blocking threads.
It's pretty simple. You could just do
#Service
public class FooService {
public Mono<Foo> findFoo(String id) {
return Mono.just(pollOnDatabase(id));
}
private Foo pollOnDatabase(String id) {
// polling on database for a while
}
}

SoapFault handling with Spring WS client - WebServiceGatewaySupport and WebServiceTemplate

I am trying to write a Spring WS client using WebServiceGatewaySupport. I managed to test the client for a successful request and response. Now I wanted to write test cases for soap faults.
public class MyClient extends WebServiceGatewaySupport {
public ServiceResponse method(ServiceRequest serviceRequest) {
return (ServiceResponse) getWebServiceTemplate().marshalSendAndReceive(serviceRequest);
}
#ActiveProfiles("test")
#RunWith(SpringRunner.class)
#SpringBootTest(classes = SpringTestConfig.class)
#DirtiesContext
public class MyClientTest {
#Autowired
private MyClient myClient;
private MockWebServiceServer mockServer;
#Before
public void createServer() throws Exception {
mockServer = MockWebServiceServer.createServer(myClient);
}
}
My question is how do i stub the soap fault response in the mock server, so that my custom FaultMessageResolver will be able to unmarshall soap fault?
I tried couple of things below, but nothing worked.
// responsePayload being SoapFault wrapped in SoapEnvelope
mockServer.expect(payload(requestPayload))
.andRespond(withSoapEnvelope(responsePayload));
// tried to build error message
mockServer.expect(payload(requestPayload))
.andRespond(withError("soap fault string"));
// tried with Exception
mockServer.expect(payload(requestPayload))
.andRespond(withException(new RuntimeException));
Any help is appreciated. Thanks!
Follow Up:
Ok so, withSoapEnvelope(payload) I managed to get the controller to go to my custom MySoapFaultMessageResolver.
public class MyCustomSoapFaultMessageResolver implements FaultMessageResolver {
private Jaxb2Marshaller jaxb2Marshaller;
#Override
public void resolveFault(WebServiceMessage message) throws IOException {
if (message instanceof SoapMessage) {
SoapMessage soapMessage = (SoapMessage) message;
SoapFaultDetailElement soapFaultDetailElement = (SoapFaultDetailElement) soapMessage.getSoapBody()
.getFault()
.getFaultDetail()
.getDetailEntries()
.next();
Source source = soapFaultDetailElement.getSource();
jaxb2Marshaller = new Jaxb2Marshaller();
jaxb2Marshaller.setContextPath("com.company.project.schema");
Object object = jaxb2Marshaller.unmarshal(source);
if (object instanceof CustomerAlreadyExistsFault) {
throw new CustomerAlreadyExistsException(soapMessage);
}
}
}
}
But seriously!!! I had to unmarshall every message and check the instance of it. Being a client I should be thorough with all possible exceptions of the service here, and create custom runtime exceptions and throw it from the resolver. Still at the end, its been caught in WebServiceTemplate and re thrown as just a runtime exception.
You could try with something like this:
#Test
public void yourTestMethod() // with no throw here
{
Source requestPayload = new StringSource("<your request>");
String errorMessage = "Your error message from WS";
mockWebServiceServer
.expect(payload(requestPayload))
.andRespond(withError(errorMessage));
YourRequestClass request = new YourRequestClass();
// TODO: set request properties...
try {
yourClient.callMethod(request);
}
catch (Exception e) {
assertThat(e.getMessage()).isEqualTo(errorMessage);
}
mockWebServiceServer.verify();
}
In this part of code mockWebServiceServer represents the instance of MockWebServiceServer class.

Quartz.net and Ninject: how to bind implementation to my job using NInject

I am actually working in an ASP.Net MVC 4 web application where we are using NInject for dependency injection. We are also using UnitOfWork and Repositories based on Entity framework.
We would like to use Quartz.net in our application to start some custom job periodically. I would like that NInject bind automatically the services that we need in our job.
It could be something like this:
public class DispatchingJob : IJob
{
private readonly IDispatchingManagementService _dispatchingManagementService;
public DispatchingJob(IDispatchingManagementService dispatchingManagementService )
{
_dispatchingManagementService = dispatchingManagementService ;
}
public void Execute(IJobExecutionContext context)
{
LogManager.Instance.Info(string.Format("Dispatching job started at: {0}", DateTime.Now));
_dispatchingManagementService.DispatchAtomicChecks();
LogManager.Instance.Info(string.Format("Dispatching job ended at: {0}", DateTime.Now));
}
}
So far, in our NInjectWebCommon binding is configured like this (using request scope):
kernel.Bind<IDispatchingManagementService>().To<DispatchingManagementService>();
Is it possible to inject the correct implementation into our custom job using NInject ? and how to do it ? I have read already few posts on stack overflow, however i need some advises and some example using NInject.
Use a JobFactory in your Quartz schedule, and resolve your job instance there.
So, in your NInject config set up the job (I'm guessing at the correct NInject syntax here)
// Assuming you only have one IJob
kernel.Bind<IJob>().To<DispatchingJob>();
Then, create a JobFactory: [edit: this is a modified version of #BatteryBackupUnit's answer here]
public class NInjectJobFactory : IJobFactory
{
private readonly IResolutionRoot resolutionRoot;
public NinjectJobFactory(IResolutionRoot resolutionRoot)
{
this.resolutionRoot = resolutionRoot;
}
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
// If you have multiple jobs, specify the name as
// bundle.JobDetail.JobType.Name, or pass the type, whatever
// NInject wants..
return (IJob)this.resolutionRoot.Get<IJob>();
}
public void ReturnJob(IJob job)
{
this.resolutionRoot.Release(job);
}
}
Then, when you create the scheduler, assign the JobFactory to it:
private IScheduler GetSchedule(IResolutionRoot root)
{
var schedule = new StdSchedulerFactory().GetScheduler();
schedule.JobFactory = new NInjectJobFactory(root);
return schedule;
}
Quartz will then use the JobFactory to create the job, and NInject will resolve the dependencies for you.
Regarding scoping of the IUnitOfWork, as per a comment of the answer i linked, you can do
// default for web requests
Bind<IUnitOfWork>().To<UnitOfWork>()
.InRequestScope();
// fall back to `InCallScope()` when there's no web request.
Bind<IUnitOfWork>().To<UnitOfWork>()
.When(x => HttpContext.Current == null)
.InCallScope();
There's only one caveat that you should be aware of:
With incorrect usage of async in a web request, you may mistakenly be resolving a IUnitOfWork in a worker thread where HttpContext.Current is null. Now without the fallback binding, this would fail with an exception which would show you that you've done something wrong. With the fallback binding however, the issue may present itself in an obscured way. That is, it may work sometimes, but sometimes not. This is because there will be two (or even more) IUnitOfWork instances for the same request.
To remedy this, we can make the binding more specific. For this, we need some parameter to tell us to use another than InRequestScope(). Have a look at:
public class NonRequestScopedParameter : Ninject.Parameters.IParameter
{
public bool Equals(IParameter other)
{
if (other == null)
{
return false;
}
return other is NonRequestScopedParameter;
}
public object GetValue(IContext context, ITarget target)
{
throw new NotSupportedException("this parameter does not provide a value");
}
public string Name
{
get { return typeof(NonRequestScopedParameter).Name; }
}
// this is very important
public bool ShouldInherit
{
get { return true; }
}
}
now adapt the job factory as follows:
public class NInjectJobFactory : IJobFactory
{
private readonly IResolutionRoot resolutionRoot;
public NinjectJobFactory(IResolutionRoot resolutionRoot)
{
this.resolutionRoot = resolutionRoot;
}
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
return (IJob) this.resolutionRoot.Get(
bundle.JobDetail.JobType,
new NonrequestScopedParameter()); // parameter goes here
}
public void ReturnJob(IJob job)
{
this.resolutionRoot.Release(job);
}
}
and adapt the IUnitOfWork bindings:
Bind<IUnitOfWork>().To<UnitOfWork>()
.InRequestScope();
Bind<IUnitOfWork>().To<UnitOfWork>()
.When(x => x.Parameters.OfType<NonRequestScopedParameter>().Any())
.InCallScope();
This way, if you use async wrong, there'll still be an exception, but IUnitOfWork scoping will still work for quartz tasks.
For any users that could be interested, here is the solution that finally worked for me.
I have made it working doing some adjustment to match my project. Please note that in the method NewJob, I have replaced the call to Kernel.Get by _resolutionRoot.Get.
As you can find here:
public class JobFactory : IJobFactory
{
private readonly IResolutionRoot _resolutionRoot;
public JobFactory(IResolutionRoot resolutionRoot)
{
this._resolutionRoot = resolutionRoot;
}
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
try
{
return (IJob)_resolutionRoot.Get(
bundle.JobDetail.JobType, new NonRequestScopedParameter()); // parameter goes here
}
catch (Exception ex)
{
LogManager.Instance.Info(string.Format("Exception raised in JobFactory"));
}
}
public void ReturnJob(IJob job)
{
}
}
And here is the call schedule my job:
public static void RegisterScheduler(IKernel kernel)
{
try
{
var scheduler = new StdSchedulerFactory().GetScheduler();
scheduler.JobFactory = new JobFactory(kernel);
....
}
}
Thank you very much for your help
Thanks so much for your response. I have implemented something like that and the binding is working :):
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
var resolver = DependencyResolver.Current;
var myJob = (IJob)resolver.GetService(typeof(IJob));
return myJob;
}
As I told before I am using in my project a service and unit of work (based on EF) that are both injected with NInject.
public class DispatchingManagementService : IDispatchingManagementService
{
private readonly IUnitOfWork _unitOfWork;
public DispatchingManagementService(IUnitOfWork unitOfWork)
{
_unitOfWork = unitOfWork;
}
}
Please find here how I am binding the implementations:
kernel.Bind<IUnitOfWork>().To<EfUnitOfWork>()
kernel.Bind<IDispatchingManagementService>().To<DispatchingManagementService>();
kernel.Bind<IJob>().To<DispatchingJob>();
To resume, the binding of IUnitOfWork is done for:
- Eevery time a new request is coming to my application ASP.Net MVC: Request scope
- Every time I am running the job: InCallScope
What are the best practices according to the behavior of EF ? I have find information to use CallInScope. Is it possible to tell NInject to get a scope ByRequest everytime a new request is coming to the application, and a InCallScope everytime my job is running ? How to do that ?
Thank you very much for your help

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