Dynamic Spring Boot-Integration configuration - java

I would like to migrate a multi-threaded application in JSE to Spring Integration but I have to clarify some points before. First of all, the application will have the following Spring integration components:
JMS to Transformer to router to TCPOut
TcpIn (to router) to Transformer to JMS
In this context, I have to load all the TCP connections dynamically from a configuration file. I saw a couple of example of this here in StackOverflow (based in the FTP sample). These samples could be enough for the first part but I am looking for how to do that in Spring Boot and what is the best (and elegant) way to create this type of configuration.
Finally, I have to access to each different context (this is maybe the most important) from a type of Swing monitor to start/stop manually this TCP connections. Is this possible? What do you suggest me to do?
All my current components are java based configuration (not DSL).

See my answers to this question and its follow-up for examples of how to dynamically create application contexts using Java Configuration.
Also, take a look at the new feature in the Java DSL for dynamically registering/removing integration flows with the context. The 1.2 version of the DSL, containing this feature, will be released shortly.
You can stop/start endpoints using JMX or a control bus, or programmatically.

Related

How to integrate GraphiQL with Spring-Boot?

My target is to build a GraphQL server on Spring with (1) GraphiQL IDE (2) dynamic GraphQL schema at run-time. My GraphQL engine is GraphQL-Java.
In my first try, I use graphql-java-spring-boot-starter-webmvc and graphiql-spring-boot-starter.
Both the GraphQL server and the GraphiQL work well.
However, under the graphql-java-spring-boot-starter-webmvc framework, a #Bean of GraphQL class is needed. In this bean, the schema is loaded when the server starts so it could not been updated.
In my second try, I don't use graphql-java-spring-boot-starter-webmvc. Instead, I choose spring-boot-starter-web to start the web server and define my own RestController. This is easy to update the GraphQL instance. But I don't find a way to integrate with GraphiQL. I googled GraphiQL+Spring but all solutions are with graphql-java-spring-boot-starter.
Appreciate if anyone could provide me an idea on either approach.
It can be enabled in properties:
graphql.graphiql.enabled=true
It is accessible via the root url +/graphiql example http://localhost:8080/graphiql
You can find a good detailed example here : https://github.com/NoorKrichen/GraphQL-Spring-Boot-Example
Do you have a sample of your setup in git?
It sounds like some configuration problem. But naturally using graphql-java-spring-boot-starter-webmvc all your *.graphql schemas should be picked up in the configured schema resource path. check if you have the path set in your application.yml or if your schema is in the configured path if its already set or by default.
On your second point: "I googled GraphiQL+Spring but all solutions are with graphql-java-spring-boot-starter."
This makes sense for quick guides and demos as using Springboot the plumbing is somehow hidden away from you so that you can focus on the technology at hand being demo'd in this case GraphQl.
On GraphiQL:
Sounds like you are intending to have this embedded with your application, you may not want to do so in production. Depending on your use case there are many other alternatives that are standalone and gives you all the functionality of GraphiQL plus more e.g Altair Graphql Client and Insomnia to name a few.

Manually setting up Spring WebSocket STOMP support

I'm trying to set up a STOMP WS endpoint using spring-websocket and spring-messaging. I am trying to do this manually: no application context is involved at all, and certainly no dispatcher. My goal is to wire up the appropriate Spring components in code inside a ServletContextListener, then register the wired up components directly with the javax.websocket.server.ServerContainer in my JSR 356 compatible container (Tomcat 7). At first, I would like to get this working with the "simple" broker built into spring-messaging; secondly, I would like to implement my own "broker" to directly integrate with an in-process ActiveMQ using the VM transport. This would be in contrast to the STOMP relay which spring-messaging also provides.
The Spring documentation states (http://docs.spring.io/spring/docs/current/spring-framework-reference/html/websocket.html):
"...Spring’s WebSocket support does not depend on Spring MVC. It is relatively simple to integrate a WebSocketHandler into other HTTP serving environments with the help of WebSocketHttpRequestHandler."
However, I am not finding it to be simple. Essentially, I started with:
public void contextInitialized(ServletContextEvent sce) {
ServerContainer websocketContainer = (ServerContainer) sce.getServletContext().getAttribute("javax.websocket.server.ServerContainer");
???
websocketContainer.addEndpoint(???);
}
And ended up with an incoherent mess of assorted spring-websocket and spring-messaging constructor invocations which do not compile and are certainly not worth reproducing here.
I realize this is a bit vague, this is because I'm a bit lost! Has anyone done something like this, or has some general guidance to contribute?
Did you try sample application - tests for the stock portfolio. (This link is at the very end of the spring documentation link).
It says
Demonstrates 3 approaches to testing a Spring STOMP over WebSocket application:
Server-side controller tests that load the actual Spring configuration (context sub-package)
Server-side controller tests that test one controller at a time without loading any Spring configuration (standalone sub-package)
End-to-end, full integration tests using an embedded Tomcat and a simple STOMP Java client (tomcat sub-package)
See the Javadoc of the respective tests for more details.
Second option is probably what you need.

JMX Remote Deployment Architecture

I'm reading up on JMX for the first time, and trying to see if its a feasible solution to a problem we're having on production.
We have an architecture that is constantly hitting a remote web service (managed by a different team on their own servers) and requesting data from it (we also cache from this service, but its a sticky problem where caching isn't extremely effective).
We'd like the ability to dynamically turn logging on/off at one specific point in the code, right before we hit the web service, where we can see the exact URLs/queries we're sending to the service. If we just blindly set a logging level and logged all web service requests, we'd have astronomically-large log files.
JMX seems to be the solution, where we control the logging in this section with a managed bean, and then can set that bean's state (setLoggingEnabled(boolean), etc.) remotely via some manager (probably just basic HTML adaptor).
My questions are all deployment-related:
If I write the MBean interface and impl, as well as the agent (which register MBeans and the HTML adaptor with the platform MBean server), do I compile, package & deploy those inside my main web application (WAR), or do they have to compile to their own, say, JAR and sit on the JVM beside my application?
We have a Dev, QA, Demo and Prod envrionment; is it possible to have 1 single HTML adaptor pointing to an MBean server which has different MBeans registered to it, 1 for each environment? It would be nice to have one URL to go to where you can manage beans in different environments
If the answer to my first question above is that the MBean interface, impl and agent all deploy inside your application, then is it possible to have your JMX-enabled application deployed on one server (say, Demo), but to monitor it from another server?
Thanks in advance!
How you package the MBeans is in great part a matter of portability. Will these specific services have any realistic usefulness outside the scope of this webapp ? If not, I would simply declare your webapp "JMX Manageable" and build it in. Otherwise, componentize the MBeans, put them in a jar, put the jar in the WEB-INF/lib and initialize them using a startup servlet configured in your web.xml.
For the single HTML adaptor, yes it is possible. Think of it as having Dev, QA, Demo and Prod MBeanServers, and then one Master MBeanServer. Your HTML Adaptor should render the master. Then you can use the OpenDMK cascading service to register cascades of Dev, QA, Demo and Prod in the Master. Now you will see all 5 MBeanServer's beans in the HTML adaptor display.
Does that answer your third question ?
JMX is a technology used for remote management of your application and for a situation for example when you want to change a configuration without a restart is the most proper use.
But in your case, I don't see why you would need JMX. For example if you use Log4j for your logging you could configure a file watchdog and just change logging to the lowest possible level. I.e. to debug. This does not require a restart and IMHO that should have been your initial design in the first place i.e. work arround loggers and levels. Right now, it is not clear what you mean and what happens with setLoggingEnable.
In any case, the managed bean is supposed to be deployed with your application and if you are using Spring you are in luck since it offers a really nice integration with JMX and you could deploy your spring beans as managed beans.
Finally when you connect to your process you will see the managed beans running for that JVM. So I am not sure what exactly you mean with point 2.
Anyway I hope this helps a little

DI in an EJB/MDB Application

I'm currently developing a small EJB application running on IBM Websphere Application Server 7 (Java EE 5). The app mainly consists of one MDB listening for incoming MQ messages which are transformed and stored in a DB. Currently I'm using a lot of Singleton/Factories to share configurations, mappings, datasource lookups etc. But this actually leads to some very hard to test code. The solution might be using a (simple) DI framework like guice/spring to inject the different instances. The question is: Where to place the initialization/ setup code? Where is the main entry point of the application? How can I inject instances into the MDBs?
it might be worth looking at backing off from using Guice, and trying to work with the injection mechanisms already available with Java EE 5.
Regarding finding a suitable "startup point", unfortunately the EJB specification does not define a way where you can have a bean run at startup. However, the web profile of the EE spec does have one -- you can add a WAR to your application, and set a servlet listener component:
http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletContextListener.html
You can set this to start whenever the application is loaded and started by the container (WebSphere). Watch out for classloader issues though.
Using Spring, you can do it via EJB3 interceptors, see http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/ejb.html#ejb-implementation-ejb3
Useful info on caveats are in the javadoc, make sure you read it: http://static.springsource.org/spring/docs/3.0.x/api/org/springframework/ejb/interceptor/SpringBeanAutowiringInterceptor.html

How to auto create a JMS topic/queue on JBoss in a portable and per-application way?

It's simple: I have an MDB and an EJB that sends messages to a topic (or queue). JBoss complains that the topic is not bound to the JNDI context.
I want to have the topic/queue to be automatically created at best, or at least to have a standard way to define it, per application (say, in ejb-jar/META-INF)
this question and this blogpost show us how to do it in an application server specific way. This surely works, but:
I want to use the #MessageDriven annotation
I want the setting not to be global for the application server
I want the setting to be portable
It seems impossible to do this, with JavaEE 5 at least.

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