In the project our team's working on, we currently have 3 separate Spring projects which utilizes the same services. To avoid redunancy and code copy-pasting, we're planning to create a "common" project wherein all the three projects would be dependent on the common project. In this instance, is it possible to inject these services (perhaps using the #Service annotation) to the Controllers of the Spring projects?
EDIT:
I tried implementing this on my own and what I basically did was I configured the pom.xml to get the Spring Context 3.1.1 dependency (which are also being used by my Spring projects) for my "common" project. With that, I was able to annotate my service with #Service. Afterwards, on my Spring project, I set the component-scan to a level wherein my two projects would meet. On my Spring controller, I #Autowired the service from the "common" project. I ran the Spring project and apparently it worked. Is this the best way to do this?
That's absolutely fine, and standard. Spring (unlike CDI) couldn't care less whether your beans come from the current project or from an imported jar.
Related
Spring boot starter project provides extensive set of functionalities auto configured. But for our application we want to have only a subset of functionality. May be only one feature out of the spring boot starter project. So is it advised to have custom starter project on top of spring boot provided starter project to mask some of the features or write new starter project directly from lower level libraries?
Spring boot starter project provides extensive set of functionalities
auto configured
There are two separate concerns you are talking about.
I think the auto configured part is something which is Spring boot's opinionated way of configuring. As an example if in classpath it finds a in-memory database library ( like H2) it automatically creates a datasource (pointing to embedded in-memory database) which is available for autowiring without you writing the configuration in a Java config class. Of course you can create you own datasource of choice by including appropriate driver jar for that database. Similarly lots of other configurations are done by default by classpath scanning and availability of certain jars and classes.
The second part - is more of a dependency issue in general. Say you want to use web mvc part in Spring boot. This will require a consistent set of dependencies and transitive dependencies as well. Rather than finding and declaring the dependency in your build tool of choice ( maven, gradle etc) it has created the concept of starter projects where you simply mention the parent and all the right dependencies would be pulled on. This gives a great way to correctly lock your dependencies. However if you want to include any different version than what is provided by boot starter ( provided there is no compatibility issues with those different versions) you can still add explicitly in your build tool. For e.g., maven will by default include the highest version of a particular dependency among all available via transitive dependencies when it resolves dependency for an artifact.
I want to know if I can keep my Spring boot class in Project A and my controller and services in Project B and invoke the end-points from Project A? The reason to do this is because I want to give Project A (which has dependency of Project B) an option to extend my controller and services to override any method.
Yes, it is a common practice to have your starter in a project and the libraries in another (spring projects are a good example for it).
it is better to have them separated in 2 repositories :faster build, version management, separation of responsibility between team members etc.
Build the project with the libraries (A)
Project with the starter (B) will have a dependency to project A
In general, it is recommended to have a configuration in project A with #ComponentScan and project B should import the configuration.
If the beans are scanned from project A, you will have access to all endpoints and services.
i created a maven project, and added all dependencies i need.
i have some repositories using the spring-data-jpa, and i added some integration tests.
now i need to add ontop of it spring-data-rest, if i understand it is based on springmvc.
but all examples i found, i need to add spring boot to start the app.
i noticed also all new spring projects use spring boot.
this means that i have to learn and use it for my projects?
how can i use spring-data-jpa+spring-data-jpa with an existing servlet3 project
The reason all examples are written using Boot is that Boot is indeed the way you should start a new Spring project these days. It free's from a lot of the tedious work of setting up the infrastructure, finding dependencies in the right version etc.
To use Spring Data REST without Boot, simply add the necessary dependencies to your project. The easiest way to do this is to use the Spring Data Release Train BOM (which will help you pulling in the correct matching versions) along side the version-less dependency declarations for Spring Data REST WebMVC and - in your case - Spring Data JPA.
Then go ahead and either register RepositoryRestMvcConvfiguration as Spring bean (either through XML configuration or JavaConfig).
All of this is also documented in the reference documentation.
I am working on a webapp which uses Primefaces as a view, and I inject Spring beans from other projects into JSF Managed beans.
I have an architectural problem:
I've created separate projects(modules) for each component that I use (Business Logic, Persistence, and others) and also create separate projects with their interfaces.
I want my webApp to depend only on the interface of the Business Logic, and to inject the implementation of the BL using Spring Dependency Injection.
I want to achive this recursively: Business logic to depend only on other interfaces, and to inject implementations using spring.
The problem is that having no dependency in the Maven pom file to the actual implementations, when I deploy the application (on a web logic server) the implementation jars are not deployed, and Spring doesn't find the beans to wire.
Is there a way to achieve decoupling without adding dependencies to actual implementations?
Can I include Spring's bean configuration files from other projects if the projects are not added as dependencies?
Did I figured this decoupling all wrong?
I appreciate your ideas.
Well obviously you need the dependencies in your maven pom else nothing will be included. You can add the dependencies with a scope of runtime which includes them in your final war but not during development (scope compile).
For loading the context of modules you might come-up with a naming convention and/or standard location for your files. With that you could do something like this in your web applications beans xml
<import resource="classpath*:/META-INF/spring/*-context.xml" />
This would load all files ending with -context.xml from the /META-INF/spring directory on the classpath (including jar files).
I'm new to Spring and try to setup a project which is split into 3 submodules. As build tool I'm using maven. My problem is, that I don't know where to add Springs "magic".
My 3 submodules are "ORM" (holds all the hibernate staff to access the database) "BusinessLogic" (which should hold the complete logic) and "WebApp" (adds as the only "client" to the app / logic).
I want to use SpringMVC for the WebApp which seems to be no problem. As "BusinessLogic" should hold the complete logic I thought of adding the Spring related stuff (Bean definition / DI) in that module. But then I don't know how to setup Spring when accessing the module form the webapp.
The hole project is being ported from a JavaEE / JBoss app where "ORM" and "BusinessLogic" (implemented as EJBs) where put into one .ear archive and the webapp into a seperate one (.war). JNDI was used to access the beans from the webapp, but I completely want to decouple the application from JBoss and deploy it on a Tomcat webserver.
At the moment I've created all three modules as separate Maven projects ("ORM" and "BusinessLogic" as .jar, "WebApp" as .war packaging), linked by a "parent" project.
Thanks for any hints on project setup :).
Greetings
Ben
you could configure spring context in your web.xml and you can perform import of Spring sub-modules context. You can add import's configuration of sub-modules in your webApp application context.