I have a server running on tomcat exposing Spring services using HttpInvoker.
I have exposed the methods of 5 services using HTTPInvoker.
This works very well.
The spring configuration is described in a file named remoting-servlet.xml; and the remoting servlet (DispatcherServlet) is described in the web.xml.
I now have an additional need to expose one additional service using JAX-WS this time (I will have C# clients).
I will use Spring support to JAX-WS.
I have the option to use the default deployment, or to use JAX-WS RI's to deploy this additional service to the same server as the remoting servlet.
I would prefer this last solution, because I would have only one server providing the remote services (whether they are web services or httpinvokers).
My question is: is this possible?
I think that I can I put the 2 servlets on the same port. But my issue is that it seems to me that I will have to provide 2 different application contexts. One for the DispatcherServlet, and one for the WSSpringServlet.
Is that correct?
Is it possible to put the WSSpringServlet context definition to the same file as the one for the httpinvokers (remoting-servlet.xml)?
Many thanks
Gilles
Related
WebLogic 12c includes a Default JAX-RS resource (https://docs.oracle.com/cd/E24329_01/web.1211/e24983/configure.htm#RESTF191) that will register all classes annotated with JAX-RS annotations as resources.
I use the Jersey proxy client (http://blog.alutam.com/2012/05/04/proxy-client-on-top-of-jax-rs-2-0-client-api/), so my interface classes have all the JAX-RS annotations and are packaged in their own "API" jar. The API jar is then deployed to basically two different contexts: the service and the client. The Service provides an implementation of the API that is the actual business logic and is exposed as a JAX-RS web service. The client is just a consumer of the service and the implementations of the service interfaces in the API jar are Jersey Proxy Clients.
Unfortunately, WebLogic 12c is causing me two problems here:
1) It is automatically registering all the resources in my API jars and exposing them as web services from the client application (with the implementation being the (now literally) proxy client)! Which is extremely unintended.
2) Sometimes I want to use classes from an API without actually consuming the service, so I don't even provide implementations for the interfaces. This should be fine, but because WebLogic is attempting to automatically load the API resources, but not finding implementations for the annotated interfaces, it refuses to deploy the war.
I could hack around issue 1 with security policies or weird jax-rs configurations in the web.xml, but that doesn't solve issue 2. The best solution is just to turn off the Default Resource in WebLogic, but I can't find any documentation to do so.
Is there any way to turn off the Default Resource in WebLogic or turn off automatic Jersey scanning?
As far as I can tell, removing these files from weblogic 12.2.1.3 completely removes jersey from starting up and scanning the classpath for annotations:
wlserver/modules/weblogic.jaxrs.integration.jar
oracle_common/modules/com.sun.jersey.jersey-core.jar
oracle_common/modules/weblogic.jaxrs.portable.server.jar
The weblogic portable server is activated by the hk2 dependency injection system, which loads jersey as an OSGI bundle and activates it
Everything I found on the internet about Spring Cloud Netflix is about running microservices from Boot applications using #EnableEurekaClients and so on.
Now I'm trying to connect my logging microservice within a traditional war application (springmvc, jaxws etc) - piece of legacy which can not be converted to Boot or modified in any way (by technical task).
I've created a new maven module "log-server-client" that knows nothing about upper web layer and intended to be used as a simple dependency in any maven project.
How should I configure access to Spring Cloud Netflix for this simple dependency? At least, how to configure Eureka and Ribbon?
I just extracted some lines of code from RestTemplate and created my custom JmsTemplate (microservice works with jms remoting with apache camel and activemq), exactly how it is done in RestTemplate, but this code stil lacks connection to infrastructure
afaik, we can create a global singleton bean, run a separate thread from this bean, and run Boot app from this thread, but don't you think that it is very ugly and can lead to problems? How it really should be used?
Great question!
One approach is to use a "sidecar". This seems to be a companion Spring Boot application that registers with the Eureka Server on behalf of your traditional web app.
See e.g.:
http://www.java-allandsundry.com/2015/09/spring-cloud-sidecar.html
http://cloud.spring.io/spring-cloud-netflix/spring-cloud-netflix.html#_polyglot_support_with_sidecar
Another approach is to use the following library:
"A small lib to allow registration of legacy applications in Eureka service discovery."
https://github.com/sawano/eureka-legacy-registrar
This library can be used outside of Spring Boot.
I am currently working on a set of REST resources that are deployed in a Tomcat servlet container. I have been using the Camel REST dsl (kickstarted by Spring) and it works very well. Now, I would like to get access to some parameters specified in the container's context.xml but havn't been able to figure out how to do that as I do not have access to the Servlet context in my route builder. Any suggestions?
Even though you are hosting your Spring-app on Tomcat, Camel is using a separate, internally loaded web server implementation for it's REST endpoints, e.g. Restlet or Spark-rest (for more infos check here). For that reason your Camel route is ignorant and entirely disconnected to your Tomcat let alone its Servlets contexts.
If I have multiple Spring Boot embedded tomcat containers and each can have service endpoints like
http://localhost:8080/employeeSelfService/getDetails
http://localhost:8081/employeeSelfService/getDetails
How can do load balancing using 2 micro services such that clients can hit any of the URL's mentioned based on some load balancing startegy
One option thats come to my mind is to use NetFlix Curator (or) have a apache webserver acting as reverse proxy but with apache, when you create new instances of your services, you will have have an entry of that service as a member in httpd.conf
Does Spring Boot provides any service discovery and load balancing mechanism ?
Spring Boot does not provide this feature, as it is already usually provided by a reverse proxy such as apache/nginx running in front of the Spring Boot server.
See here for an example here how the commercial version of nginx provides the functionality of dynamically scaling and reducing the upstream nodes.
So in this case it's for the dynamic instance, in this case the Spring Boot process to signal it's presence/unregister itself to the upstream server at initialization/shutdown.
See here how to do so in the case of nginx, this procedure will be different from server to server.
Arguably it's not really an application's role to manage its own load-balancing, and Spring Boot focuses on the implementation of an application (or service, equivalently). We have been thinking about whether we could provide features in Spring (Boot or otherwise) to make it easy to write your own load-balancer, or service registry app, but even then I don't think that was what the question was really about (or was it?).
If I interpret the question, and the example use case, literally, I would say that the most natural answer is an out-of-the-box reverse proxy solution (as the other answers pointed out). I also note that such a reverse proxy is an essential and natural part of a PaaS solution, so if you need it to "just work" and don't want to know about the details, PaaS would be a natural path (e.g. see cloudfoundry as an example of such a solution that I happen to have worked on).
Indeed Spring Boot has not inherit support for load-balancing. Just to add to the list of available solutions for load-balancing, here are the instructions to configure an Apache for load-balancing.
looks to me you need tomcat or some other servlet engine for the web part.
what about data access part using hibernate and jms? Thanks.
No, you don't need an application server, you can see Spring as a proprietary, modular application server implementation / adapter. But you still need an a servlet container.
Data access part: you can use hibernate and some standalone connection pool
jms: Spring is not a JMS provider, but it nicely integrates POJOs with any JMS provider
Spring also has comprehensive transactions support
Finally you have jmx and aop support built-in and easy integration with bean validation, jpa, web services, rmi, jci, task scheduling, caching...
As you can see you can either use certified application server and Java EE stack or built on top of Tomcat and pick Spring modules you need. Sometimes Spring uses standard Java EE APIs (like JPA), more often it builts its own.