I don't think there are particular similarities between Star Wars and Harry Potter beyond a handful of shared tropes. I mean, there are the similarities trollcatman points out, but those are pretty much the only similarities between Luke and Harry. I don't think Ron and Hans have much in common, likewise Hermione and Lea. If I may use LOTR characters to draw parallels (though weak ones), I think Hans has more in common with Aragorn, he's a handsome action hero, whereas Ron is the gawky friend of the main character who is extremely unsure of himself and spends six years essentially in Harry's shadow. If he were a LOTR character, he'd probably be Gimli.
Lea is a princess. Whilst she has her head screwed on, she doesn't have Hermione's smarts. Hermione is from a minority, and her role in the story is essentially challenging prejudice- she's a Muggle-born and a female, yet a far better wizard than Ron, Neville or even Harry and definitely Malfoy. She also stands up for the rights of werewolves, half-breeds like Hagrid, and non-humans like the elves and the centaurs.
Jory wrote:
I thought it was funny back when people were criticizing Eragon for ripping off Star Wars, since Star Wars ripped off Flash Gordon and The Hidden Fortress. I guess plagiarism is okay if the rip-off is good. Star Wars, Nosferatu, A Fistful of Dollars, Reservoir Dogs... all good, so nobody cares about their plagiarism. But Eragon sucks, so its plagiarism is focused on instead of its more serious problems.
Inheritance is more of a LOTR ripoff than Star Wars IMO, it may as well be set in Middle Earth. The Ra'zac and the Urgals are both cool, as are Paolini's dragons, but Paolini's Elves and Dwarves are both heavily derivative of Tolkien's. Not that that's particularly bad.