How to Configure Spring Framework to Accept Fluent Setters for Dependencies?

How can I configure Spring to accept fluent (non-void) setters for dependency injection?

public class MyService { 
    private Dependency dependency;

    public MyService withDependency(Dependency dependency) {
        this.dependency = dependency;
        return this;
    }
}

In Spring Framework, dependency injection is typically achieved using standard setters. However, developers may prefer using fluent setters, which return the object itself instead of void. This method enhances method chaining and improves readability. Here’s how to instruct Spring to recognize and utilize these fluent setters for dependency management.

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class FluentService {
    private Dependency dependency;

    @Autowired
    public FluentService withDependency(Dependency dependency) {
        this.dependency = dependency;
        return this;
    }
}

Causes

• Spring's default behavior only recognizes void setters for dependency injection.
• Fluent (non-void) setters are often skipped by the framework as it expects a void return type.

Solutions

• Use `@Bean` methods to define your beans without setters.
• Utilize the `@PostConstruct` annotation to handle dependency injection after object instantiation.
• Consider using `@Autowired` on the fluent method for dependency injection directly.

Mistake: Assuming Spring will automatically detect and utilize fluent setters.

Solution: Explicitly define your bean configuration to instruct Spring on how to interact with your fluent setters.

Mistake: Not using the proper annotations for structuring your classes and methods.

Solution: Ensure to annotate your classes with @Component, @Service, or similar, and use @Autowired or @Bean where necessary.