Did the legend of Excalibur stem from the Spear of Destiny?

Actually the legend - very many aspects thereof, at least - derives quite directly from Norse mythology, specifically the Völsungasaga. In Arthuriana [Arthurian legend], a young and insignificant Arthur is the only person able to pull Excalibur out of a stone, and sometime later he becomes king of Britain, his mentor being the wise wizard Merlin.

In the Völsungasaga, a mysterious elderly man, wearing a broad-brimmed hat which conceals one of his eyes, shows up at the marriage-feast of Siggeir, king of the Geats, who is being wed to Signy, the daughter of Völsung, king of the Huns. The man walks up to the Barnstokk oak-tree around which the feast-hall is built, sticks a sword into it and, after declaring that whoever can remove the sword from the tree will own it, he vanishes. Obviously the mysterious magical stranger is the god Óðinn [Odin].

Everyone tries to remove the sword, later called Gram, from the tree, but only Völsung's youngest son Sigmund manages to do this. Siggeir tries to offer him three times the sword's weight in gold but Sigmund refuses to give it up. This sparks a feud which ends in the death all of Sigmund's brothers. Signy later tricks her own brother Sigmund into having sex with her, and they have a son Sinfjötli, who avenges the deaths of his uncles by killing Siggeir. Sinfjötli is the half-brother of the more famous Sigurð Dragonslayer. Óðinn is a parallel of Merlin, and Arthur has a son Mordred by his own sister (or half-sister) Morgana le Fay, while Sigmund and Signy, both children of Völsung, are the parents of a son as well.

Sure, there might be connections to the Spear of Destiny, but that the derivation of Excalibur from the Norse sword Gram is much more striking.

If you look up the work of alan Wilson you can find the source of Excalibur it is still in existence today, was taken to American during the English civil war.

One of the king arthurs was in a battle with the romans, can't remember how it goes its either a roman general or emperor he is fighting with and the sword of the roman gets stuck in arthurs shield.

Alan Wilson has all the records and stuff to back this up.

Tales of magical spears and swords date back to the early bronze age. The discovery and smelting of metal was a great advance in human technology. These tales are also linked to the smiths who fashioned them, gifting them with magical powers or even otherworldly decent.

Excalibur is more likely to have derived from these tales than the later Dark Age interpretations of the Bible.