What are inner beans in Spring?

 A element inside the or elements defines a so-called inner bean. An inner bean definition does not require a defined id or name; the container ignores these values. It also ignores the scope flag. Inner beans are always anonymous and they are always scoped as prototypes. How can you inject Java Collection in Spring? Spring offers four types of collection configuration elements which are as follows: : This helps in wiring i.e. injecting a list of values, allowing duplicates. : This helps in wiring a set of values but without any duplicates.