Develop Reference

Guice Dependency Injection between different projects

Initially I started working on a Play! Java project that has a Controller, Processor and DAO. I used dependency injection using Google Guice's #ImplementedBy for my Processor interface and my ProcessorImpl implemented it.
Right now, I have created another project which also requires the Processor. So I extracted out the interface to another separate project, say common, and the two projects use that common project as a referenced library.
The problem is, I won't be able to use #ImplementedBy anymore since that common project will not have the two projects' references. Since that is not possible, I am not able to go for dependency injection. Without giving #ImplementedBy, I am getting the following error:
play.api.UnexpectedException: Unexpected exception[ProvisionException: Unable to provision, see the following errors:
1) No implementation for com.processor.Processor was bound.
Is there a way to configure the dependencies in a config file? Or can the dependency be injected in the implemented classes?

Create a guice module in project where your ProcessorImpl is located.
public class Module extends AbstractModule {
protected void configure() {
bind(Processor.class).to(ProcessorImpl.class);
}
}
Inject Processor wherever you need.
If you call this module Module and place it in the root package, it will automatically be registered with Play.

Glassfish 3 EJB Injection from the jar archive fails

I have a strange problem with EJB injection in the glassfish 3. Maybe I just not completely understand what I do :)
So this is a problem: My project consists of 2 modules that will be assembled with gradle.
Module A
Module B
Module A is a usual glassfish module that also works fine. Module B contains general purpose staff. Module B is also a dependency of A. Module A will be deployed to glassfish as a *.war archive and Module B is in the appropriate lib folder as *.jar archive:
module-a.war and somewere inside of it ../lib/module-b.jar
What I want is: Create in the Module B a "general purpose" stateless bean and use it in the Module A. But it doesn't work...
In the Module B I created a bean:
#Stateless
public class GeneralPurposeBean {}
and I try to use it in the Module A as follows:
...
#EJB
private GeneralPurposeBean genPurpBean;
...
So how I already mentioned the GeneralPurposeBean is in the *.jar
Each time when I try to use the bean it fails with following exception:
javax.ejb.CreateException: Could not create stateless EJB
When I move the bean to the Module A it works fine but I want share this bean with other modules, that will be developed in the future. Can someone explain to me what is wrong here? So the bean will be recognized but it can't be created. What I found out through debugging is that
JCDIServiceImpl#_createJCDIInjectionContext
Doesn't recognize the bean as an enterprise bean. So everything in the *.war that directly accessible will be properly created but not what lies in the *.jar's.

For the case someone has the same problem:
If you treat one of your modules as a dependency and this module contains EJB beans you want be injected the solution for my problem was to put /META-INF/beans.xml file into the module. Otherwise container doesn't recognize the beans as EJB.
That's it.

Using a Spring Bean from another project - Entity Manager setup.

I understand that the way these projects have been structured isn't necessarily good design, but i have found myself working on a project which has the following format and have a dependency and spring bean configuration issue:
Project A :
Is a Spring Project. Spring configuration is in an XML file. The project consists of many different beans and classes. Some of these classes are Services which make calls to a database(JPA/Hibernate is used). So in the Spring configuration file there is an entityManagerFactory defined, a Datasource etc and all the beans needed to perform database operations.
Project B:
Is also a Spring project, and also contains various beans and classes. This project also contains classes which make calls to a database(using JPA/Hibernate). So the Spring configuration also defined an entityManagerFactory/datasource etc. The project contains a series of Entity Classes which are scanned by the entityManagerFactory using the property 'packagesToScan'. The configuration is using Java Config.
The problem:
A bean in Project A needs to use a bean from Project B. The bean from project B is a Service class which reads data from the database. I want to be able to inject the bean from Project B into the class from Project A. I am using gradle in both projects, so have added Project B into Project A as a gradle dependency.
I tried adding a to the configuration from Project A to scan the package in Project B which contains the Java Config. I thought this would enable me to autowire the class from Project B into Project A. However, i am getting an exception that the entities in Project A are not managed entities and that autowiring is failing. Does this mean i need to scan the entities in Project B with the entityManager in Project A? Does this mean i cannot autowire a bean which has already been configured in the configuration of another project? Do i need to add this bean to Project A xml configuration and do all the property setting there, copied from Project B?

Add properties file from a project dependency to project classpath

I have two maven projects: project (A) and another project (B) that is a dependency of A. B contains a properties file that I wish to access in one of A's controllers. Is there a way to add B's properties file to A's classpath so that I can inject it into A's controller?
There is a similar question but I'm not sure if the scope of my question is covered by it.
UPDATE:
Using the #Value annotation in A's controller, the project returns a 500 error code and a FileNotFoundException.

Autowiring between separate projects

I have two projects namely A and B. Project A has a class C which has several global variables autowired. Project B has a class D which has to use an instance of class C for multiple purposes.
I would like to autowire the instance of C within the class D as defined in project A but keep in mind that D belongs to B.
Is there anyway I can achieve this ? For instance a way to say : " Project B, when trying to find out how to autowire classes consider the definitions and components that are defined in project A"

If you're mounting Spring JARs from other Spring projects, and you are using annotation scanning, then for your search path, you can use:
classpath*:com/my/base/package
That '*' in the classpath says search the entire class path, not just the classes in the JAR you're running out of.