Share spring container between test application and embedded tomcat - spring

We are using cucumber-jvm to write an integration test layer in our application. One of the challenges we are finding is managing the database between the tests and the web application.
A typical scenario is that we want to persist some entities in a Given step of a scenario, then perform some actions on the user interface that may, in turn, persoist more entities. At the end, we want to clean the database. Because the cucumber-jvm tests are in one jvm and the web application is running in another jvm we cannot share a transaction (at least in a way of which I am aware) so the database must be cleaned manually.
My initial thought was to use an Embedded Tomcat server running off of an embedded in-memory database (HSQLDB) in the same JVM as the cucumber-jvm test. This way we might be able to share a single spring container, and by extension a single transaction, from which all objects could be retrieved.
During my initial tests it looks like Spring gets loaded and configured twice: once when the test starts and the cucumber.xml is read, and a second time when the embedded tomcat starts and the web application reads its applicationContext.xml. These appear to be in two completely separate containers because if I try to resolve an object in one container that is specified in the other container then it doesn't resolve. If I duplicate my configuration then I get errors about duplicate beans with the same id.
Is there a way that I can tell Spring to use the same container for both my test application and the embedded tomcat?
I'm using Spring 3.2.2.GA and Embedded Tomcat 7.0.39 (latest versions of both libraries).
Am I crazy? Do I need to provide more technical details? Apologies if I use some incorrect terminology.
Thanks
p.s. If my problem seems familiar to you and you can suggest an alternative solution to the one I am trying, please let me know!

Jeff,
It is normal that spring is loaded twice. There are two places where two spring contexts are created:
In the servlet container listener org.springframework.web.context.ContextLoaderListener that is configured in web.xml. This one reads its configuration from the file set by the context-param contextConfigLocation.
In the implementation of ObjectFactory provided by cucumber-spring plugin cucumber.runtime.java.spring.SpringFactory. This one reads its configuration from cucumber.xml.
The two spring contexts are totally different and their instances are kept in two different places. As a servlet context attribute for the former and kept by the JavaBackend for the latter.
When starting the embedded tomcat, it is possible to get access to the servlet context and thus set ourself the spring context used bt tomcat with the one from cucumber. But, spring has a special class called WebApplicationContext for context used in a servlet container. The cucumber SpringFactory on other hand creates its context through ClassPathXmlApplicationContext. So unless there is a way to specify the type of application context from the xml config, we will have to provide an ObjectFactory that shoots a WebApplicationContext.

What we can do is to have two web.xml. One for the normal and one for the test. For the test, we use our version of the ContexLoader listener.

Related

Bind Spring datasource to JNDI

I have a spring boot based spring application that is deployed into an external tomcat instance.
The application creates few datasources. These datasources are added to entitymanager and transaction manager is setup accordingly.
However, recently we have integrated programmatically an ETL tool that works with JNDI datasources. The ask here is to bind the current spring datasources into the JNDI tree at startup.
I have tried to create an initial context post datasource bean creation and bind the datasources there, however, i do see a NoInitialContext exception being thrown.
How can i bind these spring datasources into the JNDI tree of the external tomcat? Appreciate the help!
Note: I cannot/am not allowed to edit the tomcat configuration as it is initialized from a PaaS template. So need to work on the approach of being able to bind to the JNDI tree from within the application.
AFAIK this is not possible. Take a look at the JEE spec:
The container must ensure that the application component instances have only read access to their naming context. The container must throw the javax.naming.OperationNotSupportedException from all the methods of the javax.naming.Context interface that modify the environment naming context and its subcontexts.
Jakarta EE Spec - Resources, Naming, and Injection
See this SO post has some interesting code examples if you want to play around.
IMHO you can achieve what you want by creating JNDI resources and passing these to the EntityManger/Spring. But that means that the configuration would exist outside of Spring completely. So this may not do what you want to do.

Can I duplicate a web service for testing?

I have a REST web service exposed at http://server:8080/my-production-ws by JBoss (7). My spring (3.2) configuration has a datasource which points to a my-production-db database. So far so good.
I want to test that web service from the client side, including PUT/POST operations but I obviously don't want my tests to affect the production database.
Is there an easy way to have spring auto-magically create another web service entry point at http://server:8080/my-test-ws or maybe http://server:8080/my-production-ws/test that will have the exact same semantics as the production web service but will use a my-test-db database as a data source instead of my-production-db?
If this is not possible, what is the standard approach to integration testing in that situation?
I'd rather not duplicate every single method in my controllers.
Check the spring Profiles functionality, this should solve the problem. With it its possible to create two datasources with the same bean name in different profiles and then activate only one depending on a parameter passed to the the JVM.

Understanding contexts in Spring MVC

I am new to spring and I am creating a simple web application. I have been reading about contexts in Spring MVC.
I am using STS plugin for eclipse. I created a
Spring MVC project using the plugin.
Now I have three xml documents in the project, web.xml, root-context.xml and servlet-context.xml. These were created by STS for me.
In web.xml, dispatcher servlet is pointed towards servlet-context.xml and I understand the dispatcher servlets job is to create a web application context which knows how to resolve views and is a place for controller beans to exist.
Is my understanding correct? If so, what other job is accomplished by this context?
Now, there is a file called root-context.xml which has a component scan on my projects default package. My understanding is this context needs to have global beans which many servlets might use. Is my understanding correct? What else does this do? What kind of context is created using this file?
Now, I am further along in the project and I have several *-context.xml files (dao-context.xml, security-context.xml etc) which are loaded using contextLoaderListner (in web.xml). Is this a good idea? Or should everything go into servlet-context.xml? I think it's a good idea to have different contexts as it provides separation of concern. Comments? Also, what kind of context is created from these *-context.xml files? What is the proper folder location for these files?
Web.xml is for the servlet container like tomcat etc and all other xml files in the project are for the spring container. Is that correct? All these files are separated to provide separation of concern?
How many application contexts and web application contexts exists in the current scenario?
Why would anyone need more than one dispatcher servlet?
Why would anyone need more than one application context?
Thoughts? Comments? Corrections? Best practices?
The whole idea behind this design is to handle different architectural layers in a typical web application and provide for inheritance / override mechanism for beans across contexts. Each type of context in Spring is related to different architectural layer for e.g, web layer, service layer etc.
A Spring based web application can have multiple dispatcher servlet configured (although in majority of cases its a single servlet - but dispatcher serlvet is a servlet nonetheless and there could be multiple configured in web.xml). These can be configured to handle different url patterns. So obviously each is a different servlet and hence can have different Spring web Application context. Each of these can contain different configurations for Spring web layer like controllers,interceptors,view resolvers,locale resolvers etc. as these typically belong to the web layer of an application. All these configurations and beans are private to each dispatcher servlet so they are not visible to each other. Hence having a seperate spring web application context makes sense to enable this privacy. However there are other beans which are designed to be shared hence belong to a root context. So all the shareable things belong to the root context and it can be considered global for this web application.
Each dispatcher servlet inherits all the beans defined in the root context. However the important point to note is that the shared beans can be overridden by respective dispatcher servlet specific beans. So in web applications root context can be viewed as something which is inherited but can be overridden.
Well spring does not force you to have xml files in that way, you can very well work everything using only one xml file that would be servlet-context.xml and using only dispatcher servlet. Generally there are different files in order to define your service beans or dao beans, so this basically depends on your application design, for eg if you are using spring security you might want to add one more xml file something like security-context.xml like as I said it depends on design. You can actually eliminate context loader listener completely and still manage to do everything using dispatcher servlet.
Your question is too broad in scope, since you are new to spring may be you should get more details about spring containers and decide what suits your requirement.
I generally have my servlet-context.xml in WEB-INF and other configuration like service-context.xml in classpath, again this is no strict rule just how it suits me.

Is it possible to change properties of a bean (defined for a service) and reload it when the application is running?

I migrated a simple CRUD application developed in Java using OSGi to Grails using Spring. I converted all the REST resources to controllers and HTML pages to GSP views, keeping the rest of the Java code as such.
I have a DBService service, which helps connect to the DB and run queries on it, and a ProcessorService, which uses DBService to perform business operations.
I created beans for these services as follows:
beans = {
dbServiceBean(DBService, "test_db")
processorServiceBean(ProcessorService,ref("dbServiceBean"))
}
Everything is working fine with the above config.
Now, I want the application to be able to process multiple DBs (multi-tenant). I won’t know the name of the DB beforehand, however, so I can’t have a list of dbServiceBeans predefined.
Is it possible to rebuild/reload a bean with dynamically obtained values and reload the dependent beans as well when the application is running?
Grails already have the option to use multiple datasources.
You can change your DBService to get a connection from the datasources configured. If you just change it to a Groovy class and put it in grails-app/service you will get transactions and dependency injection by attribute name for free.

How can i load 2 spring context in same JVM?

I've 2 applications each one uses different spring application context configuration on the same JVM, and every time i tries to run both of them together i found a problem that the last one configuration always overrides the previous one so the spring context loaded with the last one configuration, any advices how to overcome this, by letting every application runs with it's configuration without affected by other spring context.

Resources