The problem of displaying user name after java web login

CSDN Q & A 2022-05-14 14:42:18 阅读数:712

problemdisplayinguserjavaweb

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It has been extracted here 123, Finally, why did the judgment become null? solve !




Take the answer :

It is said that to judge whether a string is empty is to use empty Of , You can change it for reference
<c:if test="${empty value}"> value It's empty
<c:if test="${not empty value}"> value Not empty


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