Difference between @Autowired and @Inject annotation is that the @Inject annotation is only available from Spring 3.0 onwards, so if you want to use annotation-driven dependency injection in Spring 2.5 then you have to use the @Autowired annotation.
2) The difference between these two annotations is that unlike Spring's @Autowired, the @Inject does require the 'required' attribute.
3) The most common difference between @Autowired and @Inject annotation is that former is Spring specific while later is the standard for Dependency Injection, specified in JSR-330. In general, I recommend the use of JSR 330 annotation for DI, the @Inject annotation is as capable as Spring's @Autowired and if you want you can also mix and match this with Spring's @Value and @Lazy annotations.
4) The @Autowired annotation was added on Spring 2.5 and used for annotation driven dependency injection. It works in conjunction with @Component annotation and to streamline development cycle. From Spring 3.0, Spring offers support for JSR-330 dependency injection annotations e.g. @Inject, @Named, and @Singleton. It also added more Spring specific annotations e.g. @Primary, @Lazy, and @DependsOn annotation.
5) The @Inject annotation is good from the portability point of view. Since @Autowired is specific to Spring framework, if you ever decided to move to Google Guice or any other dependency injection framework then you need to re-implement your dependency injection logic, even though your application remains same. All bean creation logic needs to be changed to match with Google Guice's implementation.
