Obviously, cool is entered by itself, so if it is character data, it must be enclosed in single quotation marks.

int my INSERT = my statement . execute update(" INSERT INTO mynet(name，password，age，ID)VALUES("+request . getparameter(" username ")+"， "+request . getparameter(" password 1 ")+"，"+request . getparameter(" age ")+"))；

This needs to be revised.

int my INSERT = my statement . execute update(" INSERT INTO mynet(name，password，age，ID)VALUES("+request . getparameter(" username ")+" '， ' "+request . getparameter(" password 1 ")+" '，"+ request.getParameter("age") +"，"+request . getparameter(" ID ")))；

I think you will set the age id to plastic surgery, so I won't modify it for the time being.