How do I create two EntityManager binding, one without any annotation and one with annotation?

Kohei Nozaki

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Jun 13, 2016, 6:11:42 AM6/13/16

to google-guice

Hello,

I want to create two EntityManager binding with guice-persist as follows:

1. Without any annotation

2. With an annotation (say, @SlaveDatabase)

So, I have created following module:

public class MyModule extends AbstractModule {

@Override

protected void configure() {

install(new MasterPrivateModule());

install(new SlavePrivateModule());

}

private static class MasterPrivateModule extends PrivateModule {

@Override

protected void configure() {

install(new JpaPersistModule("masterPU"));

expose(EntityManager.class);

}

private static class SlavePrivateModule extends PrivateModule {

@Override

protected void configure() {

install(new JpaPersistModule("slavePU"));

final Provider<EntityManager> entityManagerProvider = binder().getProvider(EntityManager.class);

bind(EntityManager.class).annotatedWith(SlaveDatabase.class).toProvider(entityManagerProvider);

expose(EntityManager.class).annotatedWith(SlaveDatabase.class);

}

But it doesn't work. Guice produces following error:

com.google.inject.CreationException: Unable to create injector, see the following errors:

1) A binding to javax.persistence.EntityManager was already configured at mypkg.MyModule$MasterPrivateModule.configure(MyModule.java:25) (via modules: mypkg.MyModule -> mypkg.MyModule$MasterPrivateModule).

at com.google.inject.persist.jpa.JpaPersistModule.configurePersistence(JpaPersistModule.java:69) (via modules: mypkg.MyModule -> mypkg.MyModule$SlavePrivateModule -> com.google.inject.persist.jpa.JpaPersistModule)

...

How do I write a module to achieve this requirement?

I have pushed a reproducer (testcase) and entire project to GitHub:

* Entire project: https://github.com/lbtc-xxx/guice-persist-multiple-pu/tree/simplified

* Reproducer (testcase):

https://github.com/lbtc-xxx/guice-persist-multiple-pu/blob/simplified/src/test/java/mypkg/MyModuleTest.java

Thanks.