In the previous chapter, we learned how Spring Framework implements the Inversion of Control (IoC) principle. Spring IoC is the mechanism to achieve loose coupling between object dependencies. A Spring IoC container is the program that injects dependencies into an object and makes it ready for our use. Spring IoC is also known as dependency injection. In Spring, the objects of your application are managed by the Spring IoC container and are also known as beans. A bean is an object that is instantiated, assembled, and managed by a Spring IoC container. So, a Spring container is responsible for creating the beans in your application and coordinating the relationships between those objects via dependency injection. But, it is the developer's responsibility to tell Spring which beans to create and how to configure them together. When it comes to conveying a bean wiring configuration, Spring is very flexible, offering different writing configurations.

In this chapter, we first start exploring different bean wiring configurations. This includes a configuration with Java, XML, and annotations, and also learning different best practices of bean wiring configuration. We will also understand the performance assessment with different configurations, as well as dependency injection pitfalls.

This chapter will cover the following topics:

• Dependency injection configurations
• Performance assessment with different configurations
• Dependency injection pitfalls