The code marked @Before is executed before each test, while @BeforeClass runs once before the entire test fixture. If your test class has ten tests, @Before code will be executed ten times, but @BeforeClass will be executed only once. In general, you use @BeforeClass when multiple tests need to share the same computationally expensive setup … Read more
Use it every time you override a method for two benefits. Do it so that you can take advantage of the compiler checking to make sure you actually are overriding a method when you think you are. This way, if you make a common mistake of misspelling a method name or not correctly matching the … Read more
I think transactions belong on the service layer. It’s the one that knows about units of work and use cases. It’s the right answer if you have several DAOs injected into a service that need to work together in a single transaction.
@Component Preferable for component scanning and automatic wiring. When should you use @Bean? Sometimes automatic configuration is not an option. When? Let’s imagine that you want to wire components from 3rd-party libraries (you don’t have the source code so you can’t annotate its classes with @Component), so automatic configuration is not possible. The @Bean annotation … Read more
<context:annotation-config> is used to activate annotations in beans already registered in the application context (no matter if they were defined with XML or by package scanning). <context:component-scan> can also do what <context:annotation-config> does but <context:component-scan> also scans packages to find and register beans within the application context. I’ll use some examples to show the differences/similarities. … Read more
It’s a function annotation. In more detail, Python 2.x has docstrings, which allow you to attach a metadata string to various types of object. This is amazingly handy, so Python 3 extends the feature by allowing you to attach metadata to functions describing their parameters and return values. There’s no preconceived use case, but the … Read more
Since JSR 305 (whose goal was to standardize @NonNull and @Nullable) has been dormant for several years, I’m afraid there is no good answer. All we can do is to find a pragmatic solution and mine is as follows: Syntax From a purely stylistic standpoint I would like to avoid any reference to IDE, framework … Read more
From Spring Documentation: The @Repository annotation is a marker for any class that fulfils the role or stereotype of a repository (also known as Data Access Object or DAO). Among the uses of this marker is the automatic translation of exceptions, as described in Exception Translation. Spring provides further stereotype annotations: @Component, @Service, and @Controller. … Read more