With Project Reactor extras we can define retry policies directly on the WebClient API:
public Mono<String> getData(String stockId) {
return webClient.get()
.uri(PATH_BY_ID, stockId)
.accept(MediaType.APPLICATION_JSON)
.retrieve()
.bodyToMono(String.class)
.retryWhen(Retry.backoff(3, Duration.ofSeconds(2)).jitter(0.75));
}
I'm designing a library that exposes an preconfigured WebClient with some customizations. I would need to configure a default retry policy and not rely on the library users to add the .retryWhen(...) call.
Is it possible to configure a default retry policy in the WebClientBuilder or in a WebClientCustomizer?
#Configuration
public class ArchitectureWebClientConfiguration {
private final WebClient.Builder webClientBuilder;
public ArchitectureWebClientConfiguration(List<WebClientCustomizer> customizers) {
WebClient.Builder builder = WebClient.builder();
if (customizers != null && !customizers.isEmpty()) {
customizers.forEach(c -> c.customize(builder));
}
builder.xxx
this.webClientBuilder = builder;
}
#Bean
public ArchitecureWebClient architecureWebClient() {
return webClientBuilder.build();
}
Related
I have written a Reactive API using Spring WebFlux version 2.3.0.RELEASE having reactor-netty version 0.9.10. As part of the API's SLA, I want to timeout the request if the Server takes more than the stipulated configured WriteTimeout.
Sharing the code snipped below where I have implemented a customizer for NettyReactiveWebServerFactory.
#Bean
public WebServerFactoryCustomizer serverFactoryCustomizer() {
return new NettyTimeoutCustomizer();
}
class NettyTimeoutCustomizer implements WebServerFactoryCustomizer<NettyReactiveWebServerFactory> {
#Override
public void customize(NettyReactiveWebServerFactory factory) {
int connectionTimeout = 1000;
int writeTimeout = 1;
factory.addServerCustomizers(server -> server.tcpConfiguration(tcp ->
tcp.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, connectionTimeout)
.doOnConnection(connection ->
connection.addHandlerLast(new WriteTimeoutHandler(writeTimeout)))));
}
}
In spite of the Customizer, the WriteTimeout is Not Working for the API.
Instead of defining a WebServerFactoryCustomizer bean, create a bean of NettyReactiveWebServerFactory to override Spring's auto-configuration.
#Bean
public NettyReactiveWebServerFactory nettyReactiveWebServerFactory() {
NettyReactiveWebServerFactory webServerFactory = new NettyReactiveWebServerFactory();
webServerFactory.addServerCustomizers(new MyCustomizer());
return webServerFactory;
}
Now the MyCustomizer will look something like this:
public class MyCustomizer implements NettyServerCustomizer {
#Override
public HttpServer apply(HttpServer httpServer) {
return httpServer.tcpConfiguration(tcpServer -> tcpServer.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 1000)
.bootstrap(serverBootstrap -> serverBootstrap.childHandler(new ChannelInitializer<Channel>() {
#Override
protected void initChannel(Channel channel) throws Exception {
channel.pipeline().addLast("writeTimeoutHandler", new WriteTimeoutHandler(1));
}
}))
);
}
}
This is the way suggested in the official API doc
Spring boot 2.1.5
Project Reactor 3.2.9
In my webflux project I extensively use the reactor contexts in order to pass around some values.
I set up a filter and am trying to log things which are in the context and to log different things in case of error/success.
I have checked this documentation: https://projectreactor.io/docs/core/release/reference/#context
I still struggle (especially on the error side) to get it.
Basically, I have this filter:
#Component
public class MdcWebFilter implements WebFilter {
#NotNull
#Override
public Mono<Void> filter(#NotNull ServerWebExchange serverWebExchange,
WebFilterChain webFilterChain) {
Mono<Void> filter = webFilterChain.filter(serverWebExchange);
return filter
.doAfterSuccessOrError(new BiConsumer<Void, Throwable>() {
#Override
public void accept(Void aVoid, Throwable throwable) {
//Here i would like to be able to access to the request's context
System.out.println("doAfterSuccessOrError:" + (throwable==null ? "OK" : throwable.getMessage())+"log the context");
}
})
.doOnEach(new Consumer<Signal<Void>>() {
#Override
public void accept(Signal<Void> voidSignal) {
//Here i have the context but i don't really know if i am in success or error
System.out.println("doOnEach:"+"Log OK/KO and the exception" + voidSignal.getContext());
}
})
.subscriberContext(context -> context.put("somevar", "whatever"));
}
}
I also tried with a flatMap() and a Mono.subscriberContext() but i am not sure how to plug correctly with the filter (especially in error).
What would be the best way to achieve this ?
I'm not sure whether it possible access request reactor context from within WebFilter. WebFilter context exists in another Mono chain.
But it is do possible to assosiate attributes with request and able to fetch these attributes during request life time RequestContextHolder for Reactive Web
Very similar to Servlet API.
Controller:
#GetMapping(path = "/v1/customers/{customerId}")
public Mono<Customer> getCustomerById(
#PathVariable("customerId") String customerId,
ServerWebExchange serverWebExchange)
{
serverWebExchange.getAttributes().put("traceId", "your_trace_id");
return customerService.findById(customerId);
}
WebFilter:
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
// ...
String traceId = exchange.getAttributeOrDefault("traceId", "default_value_goes_here");
//...
return chain.filter(exchange);
}
I know this is probably not the cleanest of the solutions, but you could create a container class that would keep the context between your two callbacks.
You would store the context at doOnEach and then you would be able to load it back at doAfterSuccessOrError:
public Mono<Void> filter(#NotNull ServerWebExchange serverWebExchange, WebFilterChain webFilterChain) {
#lombok.Data
class MyContextContainer {
private Context context;
}
MyContextContainer container = new MyContextContainer();
Mono<Void> filter = webFilterChain.filter(serverWebExchange);
return filter
.doAfterSuccessOrError(new BiConsumer<Void, Throwable>() {
#Override
public void accept(Void aVoid, Throwable throwable) {
// load the context here
Context context = container.getContext();
// then do your stuff here
}
})
.doOnEach(new Consumer<Signal<Void>>() {
#Override
public void accept(Signal<Void> voidSignal) {
// store the context here
container.setContext(voidSignal.getContext());
}
})
.subscriberContext(context -> context.put("somevar", "whatever"));
}
It doesn't need to be a class, really. It could be an AtomicReference, but you get the idea.
Again, this might be just a workaround. I believe there must be a better way to access the context.
I want to trigger an email, after RabbitMQ Listener retrials are over and still if the process of handle failed.
retry logic is working with below code. But how to trigger the functionality (email trigger) once the max retrial attempts are over.
#Bean
public SimpleMessageListenerContainer container() {
SimpleMessageListenerContainer container =
new SimpleMessageListenerContainer(connectionFactory());
container.setQueues(myQueue());
container.setDefaultRequeueRejected(false);
Advice[] adviceArray = new Advice[]{interceptor()};
container.setAdviceChain(adviceArray);
return container;
}
#Bean
public IntegrationFlow inboundFlow() {
return IntegrationFlows.from(
Amqp.inboundAdapter(container()))
.log()
.handle(listenerBeanName, listenerMethodName)
.get();
}
#Bean
RetryOperationsInterceptor interceptor() {
return RetryInterceptorBuilder.stateless()
.maxAttempts(retryMaxAttempts)
.backOffOptions(initialInterval, multiplier, maxInterval)
//.recoverer(new RejectAndDontRequeueRecoverer())
.recoverer(new CustomRejectAndRecoverer())
.build();
}
Adding with code of CustomeRecover
#Service
public class CustomRejectAndRecoverer implements MessageRecoverer {
#Autowired
private EmailGateway emailgateway;
#Override
public void recover(Message message, Throwable cause) {
// INSERT CODE HERE.... HOW TO CALL GATEWAY
// emailgateway.sendMail(cause);
throw new ListenerExecutionFailedException("Retry Policy Exhausted",
new AmqpRejectAndDontRequeueException(cause), message);
} }
That's exactly what a .recoverer() in that RetryInterceptorBuilder is for.
You use there now a RejectAndDontRequeueRecoverer, but no body stops you to implement your own MessageRecoverer with the delegation to the RejectAndDontRequeueRecoverer and sending a message to some MessageChannel with a sending emails logic.
Sorry for my english.... May be someone help me find information about using batch job with role-based security in glassfish server?
When I invoke the method from EJB :
#Override
#RolesAllowed({"root_role", "admin_role", "user_role"})
public void execute() {
BatchRuntime.getJobOperator().start(STATISTIC_JOB_NAME, new Properties());
}
I get exception like this:
javax.ejb.AccessLocalException: Client not authorized for this invocation
My job class:
#Dependent
#Named(value = "StatisticJob")
public class StatisticJob extends AbstractBatchlet {
#EJB
private StatisticFacadeLocal sfl;
#Override
public String process() throws Exception {
System.out.println("StatisticJob.process()");
List<StatisticPortEntity> spes = sfl.findAll();
if (spes != null && !spes.isEmpty()) {
for (StatisticPortEntity spe : spes) {
System.out.println(spe);
}
} else {
return "Statistic list is empty.";
}
return "StatisticJob.proccess is done.";
}
}
How use role-based security with batch?
Thank's!
I am preparing a ReSTful service which I would like to have documented using RAML (and perhaps Swagger as well), but it seems that I cannot implement both JAX-RS and RAML in the same application at the same time.
I have created an Application class for JAX-RS as follows:
public class Application extends javax.ws.rs.core.Application {
#Override
public Set<Class<?>> getClasses() {
// Use the reflections library to scan the current package tree for
// classes annotated with javax.ws.rs.Path and add them to the JAX-RS
// application
Reflections reflections = new Reflections(this.getClass().getPackage().getName());
return reflections.getTypesAnnotatedWith(Path.class);
}
}
I attach the JAX-RS Application object as follows:
Component component = new Component();
Server server = new Server(Protocol.HTTP, PORT);
component.getServers().add(server);
JaxRsApplication jaxRsApplication = new JaxRsApplication(component.getContext().createChildContext());
jaxRsApplication.add(new Application());
jaxRsApplication.setObjectFactory(objectFactory);
component.getDefaultHost().attach("/rest", jaxRsApplication);
And I would also like to implement the RAML extension, but it looks like it is tied to the Restlet Router and having it's own Application class. Is there a way to combine the two?
Indeed the RAML extension of Restlet isn't designed to be used within JAXRS application. That said you can define a resource that provide the RAML content based on classes ApplicationIntrospector of Restlet and RamlEmitter of RAML parser, as described below:
public class RamlResource {
private Definition definition;
#Path("/raml")
#GET
public String getRaml() {
return new RamlEmitter().dump(RamlTranslator
.getRaml(getDefinition()));
}
private synchronized Definition getDefinition() {
if (definition == null) {
synchronized (RamlResource.class) {
definition = ApplicationIntrospector.getDefinition(
Application.getCurrent(),
new Reference("/"), null, false);
}
}
return definition;
}
}
It's the way the RAML extension of Restlet works. You could also use such an approach for Swagger but be careful since Swagger 1.2 requires several resources (a main and several sub ones with each categories). It's not the case anymore for Swagger 2.
You can notice that there is a JAX-RS support for Swagger in the extension org.restlet.ext.swagger.
----- Edited
Perhaps can you make a try with this class that corresponds to a port of the class JaxRsApplicationSwaggerSpecificationRestlet to RAML. It's based on the class JaxRsIntrospector which seems relevant for JAX-RS application:
public class JaxRsApplicationRamlSpecificationRestlet extends Restlet {
private Application application;
private String basePath;
private Reference baseRef;
private Definition definition;
public JaxRsApplicationRamlSpecificationRestlet(Application application) {
this(null, application);
}
public JaxRsApplicationRamlSpecificationRestlet(Context context, Application application) {
super(context);
this.application = application;
}
public void attach(Router router) {
attach(router, "/api-docs");
}
public void attach(Router router, String path) {
router.attach(path, this);
router.attach(path + "/{resource}", this);
}
public Representation getApiDeclaration() {
Raml raml = RamlTranslator.getRaml(
getDefinition());
ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
try {
return new StringRepresentation(
mapper.writeValueAsString(raml),
MediaType.APPLICATION_YAML);
} catch (Exception ex) {
return new StringRepresentation("error");
}
}
public String getBasePath() {
return basePath;
}
private synchronized Definition getDefinition() {
if (definition == null) {
synchronized (JaxRsApplicationRamlSpecificationRestlet.class) {
definition = JaxRsIntrospector.getDefinition(application,
baseRef, false);
}
}
return definition;
}
#Override
public void handle(Request request, Response response) {
super.handle(request, response);
if (Method.GET.equals(request.getMethod())) {
response.setEntity(getApiDeclaration());
} else {
response.setStatus(Status.CLIENT_ERROR_METHOD_NOT_ALLOWED);
}
}
public void setApiInboundRoot(Application application) {
this.application = application;
}
public void setApplication(Application application) {
this.application = application;
}
public void setBasePath(String basePath) {
this.basePath = basePath;
// Process basepath and check validity
this.baseRef = basePath != null ? new Reference(basePath) : null;
}
}
You can use this class like this:
JaxRsApplication application
= new JaxRsApplication(component.getContext());
MyApplication app = new MyApplication();
application.add(app);
new JaxRsApplicationRamlSpecificationRestlet(app);
(...)
There is no need for a dedicated resource. Please note that this code is a bit experimental ;-) I could propose it back for a contribution for the extension raml in Restlet...
Hope it helps you,
Thierry