Question

I have a doubt in using beans generated by another project. To be more detail :

I have a project A as follows

public A {
public void print()
{
System.out.println("Hello World");
}
}

The config class is as follows

@Configuration
public class AConfig {  
@Bean
public A a()
{
    A bean = new A();
    return A;
}
}

Now I have a new project B which has class as follows

public B {
A a;
public setA()
{
this.a = a;
}
public static void main(String[] args)  
{ 
System.out.println(a.print());
}
}

config class for B as follows

@Configuration
@Import(AConfig.class)
public BConfig
{
@Bean
public B b()
{
B bean = new B();
**b.setA(a());-----------------This is not correct. How can i get Instance of class A NOw????**
}
}

Thanks

Answer 1

Merge @Configuration classes

If beans are tightly coupled, just put them in the same class:

@Configuration
public class AConfig {  
    @Bean
    public A a() {
        return new A();
    }

    @Bean
    public B b() {
        B b = new B();
        b.setA(a());
        return b;
    }
}

Inject another @Configuration class

@Configuration class is just a special case of a bean in Spring:

@Configuration
public class BConfig {  

    @Autowired
    private AConfig aConfig;

    @Bean
    public B b() {
        B b = new B();
        b.setA(aConfig.a());
        return b;
    }
}

Inject dependencies to @Configuration class

@Configuration
@Import(AConfig.class)
public class BConfig {  

    @Autowired
    private A a;

    @Bean
    public B b() {
        B b = new B();
        b.setA(a);
        return b;
    }
}