Systematically Visit All Cells [Java]

Description: It’s harvest time and Adam must pick all of the flowers on the island. Unfortunately for Adam, he doesn’t know where the flowers are growing. Flowers could be growing anywhere on the island. In order to keep from being too exhausted, he can only visit each cell once, and he cannot try to pick from an empty cell. There are no nets, water features, or other Jeroos on the island. The purpose of this program is to find a systematic way for Adam to visit every cell exactly once, and pick the flowers from the cells that have flowers.
Download all the island files

The Maps

Note: Do not be fooled by how similar the next map is. You will probably have to rewrite some code to complete the next one.