Guava可选与Bean验证

Question

We are implementing a new Java EE Project and are not very familiar with this technology so far. So we much have to learn... Currently we are using Guava Optional in BOs to implement fields that are not mandatory.

We have a lot of discussion around this class and I don't see the advantages so far. I would prefer to using Bean Validation with the annotation @NotNull to indicate if a field is set always or not. Of course, that it's set, you can only be sure after validation.

Now to my question. Does eclipse don't show the Bean Validation Annotations? So you would better see, what you can be sure. Is there a plugin that would help?

Answer 1

Guava/Java 8 Optional should be used to enforce the following convention: if, according to bussiness logics, some function might return null value, then we wrap it inside Optional, so our intention is clear - users has to check for value presence. If a function returns non-optional object, we assume that is never can be null and users of that function do not have to do null checks. Hence the code will be much cleaner.

Since Optional is a part of Java 8 now, I guess this will become standard approach to handle nulls.

Some IDEs provide special annotation for the sake of showing hints. Eclipse has @NonNull annotation, similarly IntelliJ IDEA has @Nullable/@NotNull annotations, but they have nothing to do with Bean Validation annotation.