Play framework 2 + JPA with multiple persistenceUnit - jpa

I'm struggling with Play and JPA in order to be able to use two different javax.persistence.Entity model associated to two different persistence units (needed to be able to connect to different DB - for example an Oracle and a MySQL db).
The problem come from the Transaction which is always bind to the default JPA persitenceUnit (see jpa.default option).
Here is two controller actions which show the solution I found to manually define the persistence :
package controllers;
import models.Company;
import models.User;
import play.db.jpa.JPA;
import play.db.jpa.Transactional;
import play.mvc.Controller;
import play.mvc.Result;
public class Application extends Controller {
//This method run with the otherPersistenceUnit
#Transactional(value="other")
public static Result test1() {
JPA.em().persist(new Company("MyCompany"));
//Transaction is run with the "defaultPersistenceUnit"
JPA.withTransaction(new play.libs.F.Callback0() {
#Override
public void invoke() throws Throwable {
JPA.em().persist(new User("Bobby"));
}
});
return ok();
}
//This action run with the otherPersistenceUnit
#Transactional
public static Result test2() {
JPA.em().persist(new User("Ryan"));
try {
JPA.withTransaction("other", false, new play.libs.F.Function0<Void>() {
public Void apply() throws Throwable {
JPA.em().persist(new Company("YourCompany"));
return null;
}
});
} catch (Throwable throwable) {
throw new RuntimeException(throwable);
}
return ok();
}
}
This solution doesn't seem to be really "clean". I'd like to know if you know a better way to avoid the need to manually modify the transaction used.
For this purpose, I created a repo on git with a working sample application which shows how I configured the project.
https://github.com/cm0s/play2-jpa-multiple-persistenceunit
Thank you for your help

i met the same problem, too. too many advices are about PersistenceUnit annotation or getJPAConfig. but both them seem not work in play framework.
i found out a method which works well in my projects. maybe you can try it.
playframework2 how to open multi-datasource configuration with jpa
gud luk!

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Detecting when the database session gets refreshed on a Spring Boot 2 application

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The problem is that I'm not aware when Hibernate/Hikari are refreshing the db session, so, in practice, the application start failing when it has a couple of minutes running, as you can imagine...
My approach -that is not working yet- is to implement a EmptyInterceptor, for that I have added a DatabaseCustomizer class to inject my hibernate.session_factory.interceptor properly in a way that Spring can fill out all my #Autowires
DatabaseInterceptor.class
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#Autowired
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e.printStackTrace();
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DatabaseCustomizer.class
#Component
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#Autowired
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#Override
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hibernateProperties.put("hibernate.session_factory.interceptor", databaseInterceptor);
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Obviously, there is a problem with this approach because when I #Override the afterTransactionBegin method to start another transaction I get an Infinite loop.
I tried to look something inside that Transaction tx that could help to be sure that this transaction is not being generated by my own addPostgresConfig but there is not much on it.
Is there something else I could try to achieve this?
Thanks in advance,

Swagger documentation with JAX-RS Jersey 2 and Grizzly

I have implementated a Rest web service (the function is not relevant) using JAX-RS. Now I want to generate its documentation using Swagger. I have followed these steps:
1) In build.gradle I get all the dependencies I need:
compile 'org.glassfish.jersey.media:jersey-media-moxy:2.13'
2) I documentate my code with Swagger annotations
3) I hook up Swagger in my Application subclass:
public class ApplicationConfig extends ResourceConfig {
/**
* Main constructor
* #param addressBook a provided address book
*/
public ApplicationConfig(final AddressBook addressBook) {
register(AddressBookService.class);
register(MOXyJsonProvider.class);
register(new AbstractBinder() {
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bind(addressBook).to(AddressBook.class);
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register(io.swagger.jaxrs.listing.ApiListingResource.class);
register(io.swagger.jaxrs.listing.SwaggerSerializers.class);
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However, when going to my service in http://localhost:8282/swagger.json, I get this output.
You can check my public repo here.
It's times like this (when there is no real explanation for the problem) that I throw in an ExceptionMapper<Throwable>. Often with server related exceptions, there are no mappers to handle the exception, so it bubbles up to the container and we get a useless 500 status code and maybe some useless message from the server (as you are seeing from Grizzly).
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
public class DebugMapper implements ExceptionMapper<Throwable> {
#Override
public Response toResponse(Throwable exception) {
exception.printStackTrace();
if (exception instanceof WebApplicationException) {
return ((WebApplicationException)exception).getResponse();
}
return Response.serverError().entity(exception.getMessage()).build();
}
}
Then just register with the application
public ApplicationConfig(final AddressBook addressBook) {
...
register(DebugMapper.class);
}
When you run the application again and try to hit the endpoint, you will now see a stacktrace with the cause of the exception
java.lang.NullPointerException
at io.swagger.jaxrs.listing.ApiListingResource.getListingJson(ApiListingResource.java:90)
If you look at the source code for ApiListingResource.java:90, you will see
Swagger swagger = (Swagger) context.getAttribute("swagger");
The only thing here that could cause the NPE is the context, which scrolling up will show you it's the ServletContext. Now here's the reason it's null. In order for there to even be a ServletContext, the app needs to be run in a Servlet environment. But look at your set up:
HttpServer server = GrizzlyHttpServerFactory
.createHttpServer(uri, new ApplicationConfig(ab));
This does not create a Servlet container. It only creates an HTTP server. You have the dependency required to create the Servlet container (jersey-container-grizzly2-servlet), but you just need to make use of it. So instead of the previous configuration, you should do
ServletContainer sc = new ServletContainer(new ApplicationConfig(ab));
HttpServer server = GrizzlyWebContainerFactory.create(uri, sc, null, null);
// you will need to catch IOException or add a throws clause
See the API for GrizzlyWebContainerFactory for other configuration options.
Now if you run it and hit the endpoint again, you will see the Swagger JSON. Do note that the response from the endpoint is only the JSON, it is not the documentation interface. For that you need to use the Swagger UI that can interpret the JSON.
Thanks for the MCVE project BTW.
Swagger fixed this issue in 1.5.7. It was Issue 1103, but the fix was rolled in last February. peeskillet's answer will still work, but so will OP's now.

Eclipse Plug-In developement, long running task

I have several UI-Components which have listeners. All these listeners invoke method dialogChanged(). My goal is to make some long processing in this method and don't let the UI freeze. According to Lars Vogel it is possible to do this with help of UISynchronize being injected during runtime. But it fails for me, field of this type is not being injected and i get a NullPointerException. Here's relevant part of my code:
#Inject UISynchronize sync;
Job job = new Job("My Job") {
#Override
protected IStatus run(IProgressMonitor arg0)
{
sync.asyncExec(new Runnable()
{
#Override
public void run()
{
updateStatus("Checking connection...");
if (bisInstallDirSelected)
bisSettingsChanged();
else
jarSettingsChanged();
}
});
return Status.OK_STATUS;
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};
protected void dialogChanged()
{
job.schedule();
}
The methods updateStatus(String s), bisSettingsChanged() and jarSettingsChanged() interact with UI, to be presice, they use method setErrorMessage(String newMessage) of superclass org.eclipse.jface.wizard.WizardPage
I'd appreciate if somebody could tell me what I am doing wrong or suggest a better way to handle this problem.
You can only use #Inject in classes that the e4 application model creates (such as the class for a Part or a Command Handler).
You can also use ContextInjectionFactory to do injection on your own classes.
For classes where injection has not been done you can use the 'traditional' way of running code in the UI thread:
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New REST request in JHipster returning "Not Found - 404"

Error Description
Hey all,
I'm having trouble getting a response from my manually added controllers in a JHipster-based project. I scaffolded up the original project, and then hand-wrote my own services and controllers.
When I execute the call, the error result I get from SoapUI (which I am using for initial validation) is at the following url: http://imgur.com/04FpmEZ,Havk1EL#0
And if I look at my Eclipse console error, I see the following: http://imgur.com/04FpmEZ,Havk1EL#1
Controller
/**
* GET /courses/json -> get all the courses.
*/
#RequestMapping(value = "/json",
method = RequestMethod.GET,
produces = "application/json")
#Timed
public List<Course> getAll() {
log.debug("REST request to get all Courses");
return courseService.findAllCourses();
}
Service
package com.testapp.myapp.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.testapp.myapp.domain.Course;
import com.testapp.myapp.repository.CourseRepository;
#Service
#Transactional
public class CourseServiceImpl implements CourseService {
#Autowired
CourseRepository courseRepository;
public long countAllCourses() {
return courseRepository.count();
}
public void deleteCourse(Course course) {
courseRepository.delete(course);
}
public Course findCourse(Integer id) {
return courseRepository.findOne(id);
}
public List<Course> findAllCourses() {
return courseRepository.findAll();
}
public List<Course> findCourseEntries(int firstResult, int maxResults) {
return courseRepository.findAll(new org.springframework.data.domain.PageRequest(firstResult / maxResults, maxResults)).getContent();
}
public void saveCourse(Course course) {
courseRepository.save(course);
}
public Course updateCourse(Course course) {
return courseRepository.save(course);
}
}
What is confusing about this is that I ran the query provided by hibernate directly against my DB, and it returns the record set just fine. Is it possible that the service is being blocked due to some security or authentication constraint auto-loaded by JHipster?
A few issues existed, all related to migrating from Roo into JHipster:
I had built my new Controller class with org.sprinframework.stereotype.Controller's #Controller annotation, rather than #RestController... The original controller annotation was scaffolded up by Spring Roo (which is highly effective at generating services from an existing DB using their DBRE addon, I might add).
After switching over to #RestController, I ran into the second hurdle, which I had originally expected as a JHipster implementation : the service was being blocked due to authentication constraints.
This was fixed by going into com.[projectname].config and updating the SecurityConfiguration.java file, exposing specifically the APIs that I wanted.
Then, I had to make sure Hibernate was getting the full collection of the objects being requested (I had a lot of complex relational entities being built by Roo)... failed to lazily initialize a collection of role...
In the Domain entity, change your #OneToMany annotation as follows:
#OneToMany(fetch = FetchType.EAGER, mappedBy = "courseId", cascade = CascadeType.REMOVE)
Source of answer: Solve "failed to lazily initialize a collection of role" exception
Voila! Functioning, secure-able JSON-based APIs, fully reverse engineered from an existing Postgresql DB, loaded into a prescaffolded Angular front-end.

How to make JPA EntityListeners validate the existence of an interface

I am working in J2EE 5 using JPA, I have a working solution but I'm looking to clean up the structure.
I am using EntityListeners on some of the JPA objects I am persisting, the listeners are fairly generic but depend on the beans implementing an interface, this works great if you remember to add the interface.
I have not been able to determine a way to tie the EntityListener and the Interface together so that I would get an exception that lead in the right direction, or even better a compile time error.
#Entity
#EntityListener({CreateByListener.class})
public class Note implements CreatorInterface{
private String message;....
private String creator;
....
}
public interface CreatorInterface{
public void setCreator(String creator);
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public class CreateByListener {
#PrePersist
public void dataPersist(CreatorInterface data){
SUser user = LoginModule.getUser();
data.setCreator(user.getName());
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}
This functions exactly the way I want it to, except when a new class is created and it uses the CreateByListener but does not implement the CreatorInterface.
When this happens a class cast exception is thrown somewhere deep from within the JPA engine and only if I happen to remember this symptom can I figure out what went wrong.
I have not been able to figure a way to require the interface or test for the presence of the interface before the listener would be fired.
Any ideas would be appreciated.
#PrePersist
public void dataPersist(Object data){
if (!(data instanceof CreatorInterface)) {
throw new IllegalArgumentException("The class "
+ data.getClass()
+ " should implement CreatorInterface");
}
CreatorInterface creatorInterface = (CreatorInterface) data;
SUser user = LoginModule.getUser();
creatorInterface.setCreator(user.getName());
}
This does basically the same thing as what you're doing, but at least you'll have a more readable error message indicating what's wrong, instead of the ClassCastException.