best practices for NullPointerException when using Hibernate with Jakarta Persistence 3.0 in Java 17?
I'm having trouble with I'm converting an old project and After trying multiple solutions online, I still can't figure this out... I'm sure I'm missing something obvious here, but Quick question that's been bugging me - I tried several approaches but none seem to work. I'm currently working with a `NullPointerException` when trying to continue an entity using Hibernate with Jakarta Persistence 3.0 in my Java 17 application. The stack trace points to the line where I call `entityManager.continue(myEntity)`, but I need to seem to figure out why it's happening. I've checked that `myEntity` is not null, but it looks like the scenario might be related to the entity's relationships. Here's a snippet of the relevant code: ```java @Entity public class Order { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @ManyToOne(cascade = CascadeType.ALL) @JoinColumn(name = "customer_id") private Customer customer; // Getters and Setters } @Entity public class Customer { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String name; // Getters and Setters } ``` In my service method, I'm trying to create an `Order` object and set its `Customer`. However, the customer object appears to be null when I try to continue the order: ```java public void createOrder(Order order, Long customerId) { Customer customer = entityManager.find(Customer.class, customerId); order.setCustomer(customer); entityManager.continue(order); } ``` When I check the value of `customer` right before the continue call, it shows up as null, which indicates that the `find` method is failing to retrieve the customer. I've confirmed that the customer with the specified ID exists in the database. I have also ensured that the transaction is properly configured, and I'm using the following dependencies in my `pom.xml`: ```xml <dependency> <groupId>org.hibernate.orm</groupId> <artifactId>hibernate-core</artifactId> <version>5.6.10.Final</version> </dependency> <dependency> <groupId>jakarta.persistence</groupId> <artifactId>jakarta.persistence-api</artifactId> <version>3.0.0</version> </dependency> ``` Is there something I might be missing regarding entity management or transaction boundaries that could lead to `NullPointerException` when using the `find` method? Any insights or suggestions would be greatly appreciated! My development environment is Linux. Any help would be greatly appreciated! What's the best practice here? I'm working on a API that needs to handle this. Any ideas what could be causing this? I'm working on a application that needs to handle this. I'm using Java LTS in this project. I appreciate any insights! I'm working with Java in a Docker container on Debian. What's the best practice here?