So I just recently got into modding. I do have Java experience so I'm not completely lost. Basically I want creepers to target the player and if they can't reach the player (blocked by a wall) they blow up anyways, making a hole in the wall for other mobs to use. I've tried looking at other mods that have similar ideas but I can't figure out how they did it.

 

Thank you, Isaiah

Pathfinding will always find the shortest possible distance to the player. If you want them to explode on no path found, you will need to replace the current goal with you own that handles that. If you want it to be any obstruction, you'll probably need to reprogram the pathfinding AI.