如何在Java / MySQL中查询继承的类类型？

Question

Item is an abstract class, which is implemented by both the Material and Product classes.

The Distribution entity has an attribute "item" which is of an Item type. How do I check if the "item" is of the Product type? Right now I'm using this but it doesn't seem to be optimal.

"SELECT d FROM " + Distribution.class.getName() + " d, " + Product.class.getName() + " p WHERE d.item = p"

Answer 1

Product.class.getName() will return the fully qualified class name.

However, if you have something like :

Item item1= new Product();          Then 
item1.getClass().getSimpleName(); 

will return Product as a String type.

So you can have :

if(item1.getClass().getSimpleName().equals("Product")) {
    // Do something like 
    Product product = (Product)item1;