Spring can be invasive and non-invasive, it's only up to you.
Non-invansive spring doesn't use annotations (for example @Autowired) nor its own classes (for example JdbcTemplate), it only uses configuration to wire your beans (simple POJO) together (you still have to initialize spring somehow in your code, which is a little bit invasive anyway). But you are free to drop spring without any significant code changes. Invasive spring, on the other hand, provides you template classes (for persistence, web services,...), annotations and other stuff you cannot simply leave behind without refactoring (if you use them).
EDIT: Some say spring is not invasive, because it doesn't force you to implement interfaces nor extend classes. For me a framework is not invasive, if it can be easily replaced.
