EntityManager refresh problem

Question

I\'m getting this error from my EntityManager when I call the refresh function.

public void saveProduct(Product product) {
    entityManager.refresh(product);
}
         


        

Answer 1

From the docs of EntityManager:

IllegalArgumentException - if not an entity or entity is not managed

1. Check if your entity is mapped (using @Entity, or with .xml configuration)
2. Your entity must be persistent - i.e. managed by the entityManager. So if your entity is detached, merge() it first, and then refresh() it.

Answer 2

public void saveProduct(Product product) {
    ...

    Product managedProductEntity = entityManager.find(Product.class, product.getId());
    entityManager.refresh(managedProductEntity);

    ...
}

Works this way. managedProductEntity will be managed, and therefore it can be refreshed from database.