👀 Views: 3 💬 Answers: 1 📅 Created: 2025-06-05

Eclipse JPA Hibernate Maven MySQL Java

I'm updating my dependencies and I'm reviewing some code and I'm experiencing issues with JPA entity mapping while working on a multi-module Maven project in Eclipse 2023-09. My project structure consists of a main module for the application and a separate module for the persistence layer. I have configured Hibernate as the JPA provider, but I'm working with the following behavior when trying to run my application: ``` Exception in thread "main" javax.persistence.PersistenceException: [PersistenceUnit: myPersistenceUnit] Unable to configure EntityManagerFactory ``` The persistence.xml file is located in the `src/main/resources/META-INF/` directory of the persistence module, and it looks like this: ```xml <persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd" version="2.1"> <persistence-unit name="myPersistenceUnit"> <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> <class>com.example.model.MyEntity</class> <properties> <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/mydb" /> <property name="javax.persistence.jdbc.user" value="root" /> <property name="javax.persistence.jdbc.password" value="password" /> <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" /> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect" /> <property name="hibernate.hbm2ddl.auto" value="update" /> </properties> </persistence-unit> </persistence> ``` I have confirmed that the required Hibernate and MySQL dependencies are included in the pom.xml of the persistence module: ```xml <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>5.4.30.Final</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.23</version> </dependency> ``` I also tried to run `mvn clean install` to ensure everything is built correctly and that there are no compilation issues. The `MyEntity` class is annotated properly with JPA annotations, such as `@Entity` and `@Table`. However, I'm still getting the same exception. Additionally, I have set the project build paths correctly in Eclipse and ensured all necessary libraries are included in the build path. What could be causing this `PersistenceException`, and how can I resolve it? Any insights or suggestions would be greatly appreciated! Any suggestions would be helpful. What's the best practice here?