
Is that I write a final project , When logging in, the verification code is entered correctly , But it shows an input error , I can't log in , Instead, I entered the wrong verification code , Or no input , It can log in normally .
This is the login code and verification code :






login Of the 30 That's ok , checkcode==null || checkcode.equalsIg......
Not written or equal ?? It's obviously written backwards
checkcode==null || !checkcode.equals.....
In your opinion , Your judgment should be reversed . Add a negative sign !
1. At the time of login verification servlet Print the generated verification code and session Check whether the value in it ,
2. Look at the verification code entered in the login interface and session Whether the inside is consistent .