Stronger warning about overridden bean in case of type mismatch [SPR-16125]

[spring-projects-issues]

Nguyen The Viet opened SPR-16125 and commented

I have following classes

package com.company1

class A {
}

package com.company2

class A {
}

class B {
  A a;
  B(A a) { this.a = a; }
}

with configurations

import com.company1.*;

class Config1 {
  @Bean A a() { return new A(); };
}

import com.company2.*;

class Config2 {
  @Bean A a() { return new A(); };
  @Bean B b(A a) { return new B(a) };
}

Expected: A warning or error about duplicated bean ids
Actual: Very ambiguous error - Parameter 0 of method b in com.company.Config2 required a bean of type 'com.company2.A' that could not be found.

---

Affects: 4.3.11

[spring-projects-issues]

Juergen Hoeller commented

This seems like an unfortunate case of bean definition overriding where the overriding bean is of a different type than the overridden one, replacing it by name (as per the rules) but not providing a bean reference of the same type, leading to a bean-by-type-not found exception in code which still expects the original bean to be present.

In regular scenarios, an info-level log message "Overriding bean definition for bean..." should be issued. Could you please double-check whether that's present in your scenario? In any case, such overriding for a mix of standalone beans and @Bean-defined beans within configuration classes can be a bit tricky. Let's try to improve this as far as possible, at least providing clearer guidance in case of a type mismatch.

[spring-projects-issues]

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[spring-projects-issues]

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