Now that you have reached this chapter, you should know what Dependency Injection (DI) is, why it's so important, how it's projected in recent versions of Java, and how to implement it with popular frameworks, such as Spring and Google Guice, with various scopes.
It's said that knowing something is not enough until it's applied with best methodologies and practices. Knowledge is power only when it's implemented in the right manner. An improper approach may create a big mess.
The software industry is moving toward modularity. The concepts of DI and Inversion of Control (IoC) containers were created due to this, and this is why they are so popular today. Still, many developers don't know how to utilize DI to its full potential.
In this chapter, we will explore the real strength of DI by learning the right patterns and best practices to apply the expertise we gained in DI in previous chapters. This chapter is not meant to do anything new; instead, we will learn how to do things in the right manner.
In this chapter, we will cover the following topics:
- Various patterns to achieve IoC
- Configuration styles
- Injection using the setter method versus constructor
- Circular dependency
- Best practices and anti-patterns