# JPA entity classes are not discovered automatically with Gradle **URL:** \ **Category:** Help/Discuss\ **Created:** [August 25, 2015, 9:42pm UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339 "2015-08-25T21:42:47Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![marcos\_aps](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@marcos\_aps](https://discuss.gradle.org/u/marcos_aps)\ **Post date:** [August 25, 2015, 9:42pm UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339/1 "2015-08-25T21:42:47Z")
I’m new to Gradle. I’m trying to run some tests but they fail with messages showing that the entity classes are not mapped. When I explicitly map the classes in _persistence.xml_ everything works fine. I did some research and found that adding theses lines to the build script would solve the problem: > sourceSets.main.output.resourcesDir = sourceSets.main.output.classesDir > sourceSets.test.output.resourcesDir = sourceSets.test.output.classesDir but it simply didn’t work for me. I still get the errors if I don’t specify the classes in the deployment descriptor. What could be wrong? Cross-posted: [java - JPA entity classes are not discovered automatically with Gradle - Stack Overflow](http://stackoverflow.com/questions/32214111/jpa-entity-classes-are-not-discovered-automatically-with-gradle) ---
**Author:** ![Shinya\_Mochida](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/shinya_mochida/32/2393_2.png) [@Shinya\_Mochida](https://discuss.gradle.org/u/Shinya_Mochida)\ **Post date:** [August 25, 2015, 10:11pm UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339/2 "2015-08-25T22:11:29Z")
Hi, Marcos. Can I see your `persistence.xml` and project structure( and `build.gradle`)? And did you test it in Java SE environment, or in Java EE container? ---
**Author:** ![marcos\_aps](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@marcos\_aps](https://discuss.gradle.org/u/marcos_aps)\ **Post date:** [August 25, 2015, 10:29pm UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339/3 "2015-08-25T22:29:28Z")
I’m testing in Java SE. persistence.xml: ``` br.desenvolvimento.teste.modelo.Cliente br.desenvolvimento.teste.modelo.Banco br.desenvolvimento.teste.modelo.AgenciaBancaria br.desenvolvimento.teste.modelo.ContaBancaria br.desenvolvimento.teste.modelo.Filho br.desenvolvimento.teste.modelo.Projeto br.desenvolvimento.teste.modelo.Telefone ``` My project structure: ``` C:\desenvolvimento\teste\teste\.classpath C:\desenvolvimento\teste\teste\.gradle C:\desenvolvimento\teste\teste\.project C:\desenvolvimento\teste\teste\.settings C:\desenvolvimento\teste\teste\build.gradle C:\desenvolvimento\teste\teste\cfg.properties C:\desenvolvimento\teste\teste\gradle C:\desenvolvimento\teste\teste\gradlew C:\desenvolvimento\teste\teste\gradlew.bat C:\desenvolvimento\teste\teste\src C:\desenvolvimento\teste\teste\.settings\gradle.prefs C:\desenvolvimento\teste\teste\gradle\wrapper C:\desenvolvimento\teste\teste\gradle\wrapper\gradle-wrapper.jar C:\desenvolvimento\teste\teste\gradle\wrapper\gradle-wrapper.properties C:\desenvolvimento\teste\teste\src\main C:\desenvolvimento\teste\teste\src\test C:\desenvolvimento\teste\teste\src\main\java C:\desenvolvimento\teste\teste\src\main\resources C:\desenvolvimento\teste\teste\src\main\java\br C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\AgenciaBancaria.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Banco.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Cliente.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\CodigoAgenciaBancaria.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\CodigoCliente.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\CodigoContaBancaria.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\CodigoFilho.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\CodigoTelefone.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\ContaBancaria.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Endereco.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Filho.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Projeto.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Sexo.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\Telefone.java C:\desenvolvimento\teste\teste\src\main\java\br\desenvolvimento\teste\modelo\TipoSangue.java C:\desenvolvimento\teste\teste\src\main\resources\META-INF C:\desenvolvimento\teste\teste\src\main\resources\META-INF\img C:\desenvolvimento\teste\teste\src\main\resources\META-INF\MANIFEST.MF C:\desenvolvimento\teste\teste\src\main\resources\META-INF\menu.xml C:\desenvolvimento\teste\teste\src\main\resources\META-INF\persistence.xml C:\desenvolvimento\teste\teste\src\main\resources\META-INF\img\icone.gif C:\desenvolvimento\teste\teste\src\main\resources\META-INF\img\localizar.gif C:\desenvolvimento\teste\teste\src\test\java C:\desenvolvimento\teste\teste\src\test\resources C:\desenvolvimento\teste\teste\src\test\java\br C:\desenvolvimento\teste\teste\src\test\java\br\desenvolvimento C:\desenvolvimento\teste\teste\src\test\java\br\desenvolvimento\teste C:\desenvolvimento\teste\teste\src\test\java\br\desenvolvimento\teste\teste C:\desenvolvimento\teste\teste\src\test\java\br\desenvolvimento\teste\teste\TesteFormatacao.java C:\desenvolvimento\teste\teste\src\test\resources\META-INF C:\desenvolvimento\teste\teste\src\test\resources\META-INF\persistence.xml ``` I tried to upload an image of my project structure because it’s better to view, but new users like me are forbidden ---
**Author:** ![Shinya\_Mochida](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/shinya_mochida/32/2393_2.png) [@Shinya\_Mochida](https://discuss.gradle.org/u/Shinya_Mochida)\ **Post date:** [August 26, 2015, 1:08am UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339/4 "2015-08-26T01:08:11Z")
In Java SE environment with Hibernate, `class` elements is needed in `persistence-unit` element. In [JPA2.1 Specification(JSR338 8.2.1.6.4)](https://jcp.org/aboutJava/communityprocess/final/jsr338/index.html), it is described that > A list of all named managed persistence classes must be specified in Java SE environments to insure > portability. Portable Java SE applications should not rely on the other mechanisms described here to > specify the managed persistence classes of a persistence unit. If you do not want to list classes, there are several ways to generate `persistence.xml`. - generate `persistence.xml` with Annotation Processor. - generate `persistence.xml` with Gradle custom task(, but it’s not available on executing test in IDE). - let IDE to list classes ---
**Author:** ![marcos\_aps](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@marcos\_aps](https://discuss.gradle.org/u/marcos_aps)\ **Post date:** [August 26, 2015, 1:23am UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339/5 "2015-08-26T01:23:17Z")
I’ve been programming in Java SE using JPA for more than six years and I can assure you that, before using Gradle, I have never had the need to explicitly specify the entity classes that reside in the same jar where persistence.xml reside for my application to work. And I don’t even have to list them if I’m running in Java EE. Sometimes I only have to list the classes if they are located in another jar, which is not the case here. It would be very sad from the JPA specification if I had to declare all my classes in the deployment descriptor that lives in the same jar. Again, before using Gradle (at least for testing), I didn’t need to declared the mapped classes in persistence.xml for the application to work. They were discovered automatically. ---
**Author:** ![bhunt](https://sea1.discourse-cdn.com/gradle/user_avatar/discuss.gradle.org/bhunt/32/5728_2.png) [@bhunt](https://discuss.gradle.org/u/bhunt)\ **Post date:** [November 16, 2016, 7:22pm UTC](https://discuss.gradle.org/t/jpa-entity-classes-are-not-discovered-automatically-with-gradle/11339/6 "2016-11-16T19:22:01Z")
I’ve debugged this to root cause. When running unit tests, Gradle puts build/resources/main on the classpath which contains META-INF/persistence.xml. Hibernate (at least version 3.6.7) loads persistence.xml using the context class loader and extracts the URL of persistence.xml. The URL looks like /…/build/resources/main/META-INF/persistence.xml. From this URL, Hibernate then extracts the jarURL as /…/build/resources/main/. It is this URL that is used to scan for classes annotated with @Entity for which there are none since the classes are in build/classes. When you set: `sourceSets.main.output.resourcesDir = sourceSets.main.output.classesDir` Gradle puts the META-INF/persistence.xml in build/classes. Now, when Hibernate runs, it finds persistence.xml in /…/build/classes/main/META-INF/persistence.xml which then turns into a jarURL of /…/build/classes/main which does contain your classes annotated with @Entity and everything now works.