Single Entry/Single Exit Philosophy in Java from Unit Testing in Java

I think it really depends on the situation and the complexity of the code inside the method (in which case the method should probably be broken down farther).

The single exit principle is pretty dogmatic and like you said antiquated. The single return was actually originally attempting to tackle the spaghettiness of GOTO statements, and it has long been misunderstood to be returning from when the original problem it was solving was returning to. That being said others have made cases for when this principle is still valid in a Java return way. But that said, it's dogmatic in most cases and does not improve legibility.

If your code doesn't produce side effects, I actually think that the sooner you can exit a method the better. But that's a matter of taste and team. Always follow whatever style is in place, but if I am writing new code, I usually always default on returning early and often. I think it reads cleaner in most cases.

I'm going to do a little Google hunting to see what popular style guides say about it, and I'll let you know my findings.