Why is Budai often associated with the future Buddha Maitreya? Many times I've heard of Budai (pictured below) being associated with Maitreya, the future Buddha. Why is this so and how widespread is this belief? Wikipedia lists a short verse uttered before Budai's death:


  Maitreya, the true Maitreya
  has billions of incarnations.
  Often he is shown to people at the time;
  other times they do not recognize him.


Is there more to this association or was the simple utterance of that verse so long ago the sole reason for believing that Budai was the bodhisatta?
Here is a reference to the Japanese Miroku Bodhisatva.

Another reference says that Hotei was Kaishi Zen priest and a Boddhisattva, the future Maitreya:


  Hotei stands out from the other six Lucky Gods because he is the only one known to have been a real person, rather than a mythical being. According to Chiba, his Chinese name was Kaishi. His birth date is unknown, but his date of death was in March of the year 916. He was a Zen priest who could quote Buddhist text verses almost nonstop. Some sources affirm that he was an  incarnation of the Bodhisattva Miroku (Maitreya in Sanskrit), the Buddhist Savior of the Future (Giraud 404). However, some of his actions would not be  considered particularly saintly. For example, he would beg for meat and fish  even though they were foods forbidden to priests.


Bits of details about claims to Maitreya and where references of it could be found in the pali canon.