Cannot declare List property in the JPA @Entity class. It says 'Basic' attribute type should not be a container

Question

I have a JPA @Entity class Place , with some properties holding some information about a place, such as name of place, description, and URLs of some images.

For the URLs of images, I declare a List<Link> in my entity.

However, I am getting this error:

Basic attribute type should not be a container.

I tried to remove @Basic , but the error message is still there. I have no idea why it shows this error.

Any help?

Answer 1

You are most likely missing a relational (like @OneToMany ) annotation and/or @Entity annotation.

I had a same problem in:

@Entity
public class SomeFee {
    @Id
    private Long id;
    private List<AdditionalFee> additionalFees;
    //other fields, getters, setters..
}

class AdditionalFee {
    @Id
    private int id;
    //other fields, getters, setters..
}

additionalFees was the field causing the problem.

What I was missing and what helped me are the following:

1. @Entity annotation on the Generic Type argument ( AdditionalFee ) class;
2. @OneToMany (or any other type of appropriate relation fitting your case) annotation on the private List<AdditionalFee> additionalFees; field.

So, the working version looked like this:

@Entity
public class SomeFee {
    @Id
    private Long id;
    @OneToMany
    private List<AdditionalFee> additionalFees;
    //other fields, getters, setters..
}
    
@Entity
class AdditionalFee {
    @Id
    private int id;
    //other fields, getters, setters..
}

Answer 2

You can also use @ElementCollection :

@ElementCollection
private List<String> tags;

Answer 3

将列表类型的@basic更改为@OneToMany

Answer 4

As the message says, @Basic should not be used for containers (eg Java collections). It is only to be used for a limited list of basic types. Remove the @Basic annotation on that field.

If, as you say in the question, the error message is still there, you might need to try the following steps in order:

1. Save the file
2. Close and reopen the file
3. Clean and rebuild the project
4. Restart the IDE

(these are generic steps, which I use when an IDE is generating a compilation error that obviously makes no sense.)

Answer 5

The error seems not have impact on GAE since I can run the app and store data into storage. I guess it's a bug in IntelliJ IDEA and you can simply ignore it.

Answer 6

This can also happen when your class is missing its @Entity annotation. When you get weird warnings like these, sometimes it helps to try and compile and see if the compiler complains.

Answer 7

Or you can mark it as @Transient if it doesn't exist on DB table.

@Transient
private List<String> authorities = new ArrayList<>();