Spring does not reliably detect circular imports in Java configurations [SPR-13852]

[spring-projects-issues]

Armand Beuvens opened SPR-13852 and commented

After investigation on some issues on non detected circular imports inside Java configuration classes, it seems that there is a bug inside the contains method of the inner class ImportStack of the class ConfigurationClassParser:

@Override
public boolean contains(Object elem) {
	ConfigurationClass configClass = (ConfigurationClass) elem;
	Comparator<ConfigurationClass> comparator = new Comparator<ConfigurationClass>() {
		@Override
		public int compare(ConfigurationClass first, ConfigurationClass second) {
			return (first.getMetadata().getClassName().equals(second.getMetadata().getClassName()) ? 0 : 1);
		}
	};
	return (Collections.binarySearch(this, configClass, comparator) != -1);
}

The bianrySearch method of Collections is called without sorting the collection before which can lead to undefined results.

---

Affects: 4.2.3

Issue Links:

• Do not fail with a circular @Import error caused by an @ComponentScan [SPR-14517] #19086 Do not fail with a circular @Import error caused by an @ComponentScan

Referenced from: commits e14c2de, 77b8f4d

[spring-projects-issues]

Juergen Hoeller commented

That code seems to be rather outdated since ConfigurationClass.equals is based on class name equivalence these days anyway. So I'm simply removing it in favor of the standard contains implementation there.

I'm also changing the base class to java.util.ArrayDeque (JDK 6+ which is alright with us these days) in favor of the generally outdated java.util.Stack.

Juergen