Having an Apache Camel route defined in Java, I can do something like this
from("stream:in?promptMessage=Enter something: ")
.loadBalance()
.to("uria", "urib")
and it works like a charme.
Trying this using a Spring context file doesn't work out:
<c:camelContext id="defaultContext">
<c:route id="defaultRoute">
<c:from uri="stream:in?promptMessage=Enter something: "/>
<c:loadBalance inheritErrorHandler="false">
<c:to uri="uria, urib"/>
</c:loadBalance>
<c:to uri="stream:out"/>
</c:route>
</c:camelContext>
Any idea, how i can set more than one uri per <c:to ... element? I do not want to have multiple <c:to ... elements. Is there any way, e.g. having a route factory passing the list?
What is the cause I want to achieve this: I'd like to inject a list of URIs from a configuration file passing them directly to the Camel route.
I'm using version 2.12.1 of Apache Camel.
Use a RouteBuilder class to create a route that reads URI's from somewhere.
Use contextScan to load the route builder class into spring camel context. Refer section Using contextScan on apache's site.
The RouteBuilder class shall be
#Component
public class MyRoute extends SpringRouteBuilder {
#Override
public void configure() throws Exception {
String URIs = // read all URI's from file or somewhere
from("direct:start")
.loadbalance()
.to(URIs);
}
}
Related
Quarkus using Rest Client, explains how to use the MicroProfile REST Client. For Base URL application.properties can be used.
org.acme.restclient.CountriesService/mp-rest/url=https://restcountries.eu/rest #
With above approach, cant have dynamic base URL.
Able to achieve it by using RestClientBuilder as explained in MicroProfile Rest Client. Downside of this approach is not having auto-negotiation capability.
SimpleGetApi simpleGetApi = RestClientBuilder.newBuilder().baseUri(getApplicationUri()).build(SimpleGetApi.class);
Is there other or better way to achieve this? Thanks.
While it is true, that the MP Rest CLient does not allow you to set the BaseUri dynamically when you use declarative/Injected clients, there are some (albeit hacky) ways how to achieve that.
One is to use standard ClientRequestFilter which can modify the URL:
#Provider
#Slf4j
public class Filter implements ClientRequestFilter {
#Inject RequestScopeHelper helper;
#Override
public void filter(ClientRequestContext requestContext) throws IOException {
if (helper.getUrl() != null) {
URI newUri = URI.create(requestContext.getUri().toString().replace("https://originalhost.com", helper.getUrl()));
requestContext.setUri(newUri);
}
}
}
Where RequestScopeHelper is some help class (e.g. request scoped bean) through which you can pass the dynamic url, for example:
#Inject
RequestScopeHelper helper;
#Inject
#RestClient
TestIface myApiClient;
public void callSomeAPIWithDynamicBaseUri(String dynamic) {
helper.setUrl(dynamic);
myApiClient.someMethod();
}
Second is to use MP rest client SPI, namely the RestClientListener which allows you to modify the rest clients after they are built.
For this to work, you have to set the scope of your rest client to RequestScoped so that new instance is created for each request(if you use singleton for example, then the client is only created once and your listener will only be called once). This you can do via quarkus properties:
quarkus.rest-client."com.example.MyRestIface".scope=javax.enterprise.context.RequestScoped
public class MyListener implements RestClientListener {
#Override
public void onNewClient(Class<?> serviceInterface, RestClientBuilder builder) {
String newUri = //obtain dynamic URI from somewhere e.g. again request scope bean lookup, or maybe dynamic config source (create new in-memory ConfigSource, before you invoke your rest client set the corresponding rest client url property to your dynamic value, then inside this listener use ConfigProvider.getConfig().getProperty...)
builder.baseUri(URI.create(newUri));
}
}
Don't forget to register this listener as service provider(META-INF/services/org.eclipse.microprofile.rest.client.spi.RestClientListener)
Another option is to use custom CDI producer that would produce the Rest client instances for you; then you could control all client config yourself. You can use the RestClientBase from Quarkus rest client which is exactly what Quarkus uses under the hood during deployment phase to construct client instances. You will however have to duplicate all the logic related to registration of handlers, interceptors etc.
Do keep in mind, that any of these solutions will make the debugging and problem analysis more challenging - because you will now have multiple places, where the URI is controlled(MP config/quarkus properties, env vars, your custom impl...), so you need to be careful with your approach and maybe add some explicit log messages when you override the URI manually.
MicroProfile REST Client in Quarkus does allow you to use dynamic base URL with that simple "hack" :
Just put an empty String in #Path annotations for you API interface like that :
import javax.ws.rs.GET;
import javax.ws.rs.Path;
#Path("")
public interface SimpleGetApi {
#Path("")
#GET
String callWithDynmamicUrl(); //it can be String or any return type you want
}
After that you are ready to call your dynamic base URL :
import org.eclipse.microprofile.rest.client.RestClientBuilder;
import java.net.URI;
public class Example {
public static void main(String[] args) {
URI anyDynamicUrl = URI.create("http://restcountries.eu/rest/some/dynamic/path");
SimpleGetApi simpleGetApi = RestClientBuilder.newBuilder().baseUri(anyDynamicUrl)
.build(SimpleGetApi.class);
simpleGetApi.callWithDynmamicUrl();
}
}
Is there an option to specify a request header once in spring web RestController instead of doing it on every request?
e.q.
#RestController("workflowController")
public class MyClass{
public Value list(#RequestHeader(USER_ID_HEADER_PARAM) String user) {
...some code
}
public Workflow create(#RequestBody Workflow workflow, #RequestHeader(USER_ID_HEADER_PARAM) String user) {
... some code
}
}
the #RequestHeader(USER_ID_HEADER_PARAM) will be repeated in every request.
is there a way to specity it in the #RestCotroller level or the class level?
Thanks
Use some kind of filter class that can be configured to wrap around your requests in your servlets based on the URL path.
Here is info about the generic Servlet API filter API:
https://www.oracle.com/technetwork/java/filters-137243.html
If you're using Spring, there's another way to do it:
https://docs.spring.io/spring/docs/current/spring-framework-reference/web.html#filters
https://www.baeldung.com/intercepting-filter-pattern-in-java
I am trying to instantiate a resolver from spring-cloud-aws-messaging, specifically the NotificationMessageArgumentResolver. The problem is that it takes a MessageConvertor as an argument. So, this is what I have so far:
private NotificationMessageArgumentResolver notificationMessageArgumentResolver() {
new NotificationMessageArgumentResolver(this.messageConvertor);
}
To get the messageConvertor, I have tried:
#Autowired
public MvcConfig(MessageConvertor messageConvertor) {}
#Autowired
public MvcConfig(MappingJackson2MessageConverter messageConvertor) {}
but I get the same error either ways no bean found. The documentation is simply asking to use the XML:
<mvc:annotation-driven>
<mvc:argument-resolvers>
<ref bean="notificationResolver" />
</mvc:argument-resolvers>
<aws-messaging:notification-argument-resolver id="notificationResolver" />
Which, according to the doc
registers three argument resolvers: NotificationStatusHandlerMethodArgumentResolver, NotificationMessageHandlerMethodArgumentResolver, and NotificationSubjectHandlerMethodArgumentResolver.
So, following the answer from How to use argument-resolvers using annotation in Spring boot?, I am able to get 2 of the 3 beans added, as they don't need any beans I cannot access, however I am not able to instantiate NotificationMessageArgumentResolver due to the lack of a MessageConvertor. I am expecting all my messages to come purely in JSON, so I do know exactly which MessageConvertor to use, which is the default one for JSON that ships with Spring Boot.
EDIT
The entire file, if anyone is interested: http://pastebin.com/tM471AEv
I wonder if you really need the NotificationMessageArgumentResolver as that is intended to be used when using messaging. As you can see it implements the HandlerMethodArgumentResolver from the org.springframework.messaging package.
I suspect that you want to use the NotificationMessageHandlerMethodArgumentResolver instead. Which is the HandlerMethodArgumentResolver for use with the web instead of messaging. Which is also registered when using <aws-messaging:notification-argument-resolver id="notificationResolver" />
I would also suggest to use the NotificationHandlerMethodArgumentResolverFactoryBean instead of 3 individual beans as that is also the class that is used internally by the namespace and annotation driven configuration.
Your configuration would look something like this.
#Bean
public NotificationHandlerMethodArgumentResolverFactoryBean notificationHandlerMethodArgumentResolverFactoryBean() {
return new NotificationHandlerMethodArgumentResolverFactoryBean();
}
#Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(notificationHandlerMethodArgumentResolverFactoryBean.getObject());
}
I'm using Jersey, and Guice as my IOC-container. I'd like to know if it is possible to associate an ExceptionMapper with a specific URI. The reason for this is that I want to map the same exception differently based on what URI was visited. For example, suppose I've got the following two exception mappers for my custom exception:
public class MyExceptionMapperForFirstURI implements
ExceptionMapper<MyException> {..return response based on first URI..}
public class MyExceptionMapperForSecondURI implements
ExceptionMapper<MyException> {..return response based on second URI..}
As far as I understand you bind an ExceptionMapper in your ServletModule as follows:
public class MyModule extends ServletModule {
#Override
public void configureServlets() {
super.configureServlets();
bind(MyCustomExceptionMapper.class);
}
}
How would I go about binding MyExceptionMapperForFirstURI and MyExceptionMapperForSecondURI so that they get associated with the correct URIs. Is this possible, and if possible: is this the correct way to do this?
This is quite late answer ;-) but you can always inject the UriInfo and branch on that. So,
#Context
UriInfo uriInfo;
.....
if (matchesA(uriInfo.getAbsolutePath())) {
// do something
}
Not sure how the URI's of your app look like, but if it is possible to split your app into two servlets or filters, then you can do it like that - i.e. have one servlet/filter serve one set of resources and include the first mapper and have the other servlet/filter serve the other set of resources and include the other mapper.
If these are custom exceptions, you can also pass Request as an argument to the exception and have just a single mapper - decide on the response based in the request uri in the mapper.
Is it possible to write a custom JSP tag to take an i18n message key and output the translation phrase for the given request?
Normally in JSP/JSTL, I do:
<fmt:message key="${messageKey}"><fmt:param>arg1</fmt:param></fmt:message>
And I get the translation phrase. Now I need to do the following (there's a good reason for this):
<custom:translate key="${messageKey}" arg="arg1"/>
But I don't know how to look up the translation in the custom tag code. The TagSupport base class provides a pageContext from which I can get a ServletRequest which has the Locale... but how do I then look up the translation for a key?
I use Spring 3.0 and in my application-context.xml, I've defined a ReloadableBundleMessageSource so I can call:
messageSource.getMessage(
key, new Object[] {arg}, pageContext.getRequest().getLocale()
);
but I don't think I can inject messageSource into a custom tag, can I? Otherwise I can instantiate a new one, but would it load my tens of thousands of translations for every call? I don't want to resort to making messageSource a static member of a static class.
I don't do Spring, but in "plain" JSP you can just put the ResourceBundle instance in the session scope with help of a Filter or Servlet
ResourceBundle bundle = ResourceBundle.getBundle(basename, request.getLocale());
request.getSession().setAttribute("bundle", bundle);
And treat it in JSP like any other bean in EL.
${bundle[messageKey]}
It must be possible to have Spring to put that as a bean in the session scope.
There is a utility in spring to access the web application context. Then you can look up a bean by its name or type.
To get hold of your resource bundle, you could do something like:
WebApplicationContext springContext = WebApplicationContextUtils.getWebApplicationContext(pageContext.getServletContext());
messageResource = springContext.getBean("messageResource");
This question is very old but I think it is worth to share another way to solve this.
To access the Spring message source in a custom tag you only need to extend the class org.springframework.web.servlet.tags.RequestContextAwareTag instead of TagSupport.
In this case you have to implement the method doStartTagInternal() instead of doStartTag(), but inside this method you will have access to the MessageSource through getRequestContext().getMessageSource() method.
Therefore, your class would look like:
public class CreateCustomFieldTag extends RequestContextAwareTag{
//variables (key, arg...), getters and setters
#Override
protected int doStartTagInternal() throws Exception {
getRequestContext().getMessageSource().getMessage(
key, new Object[] {arg}, getRequestContext().getLocale());
}
}