Depends on how you want to validate it. If you simply want to validate the format, then you need to use the java.util.regex package. An email address should be in the form: [A-Za-z1-0]*@[A-Za-z1-0]*\.[A-Za-z1-0]* that is, any number of alpha-numeric characters followed by an ampersand followed by any number of alpha-numeric characters followed by a '.' followed by any number of alpha-numeric characters. If you want to validate if it is a valid address (instead of somehting like email@example.com), then you will need to send an e-mail to that address and see it if is received (does not bounce).
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