sob., 13 wrz 2025 o 14:05 Selim H <selim.houmm...@gmail.com> napisał(a): > > Hello, > > I'm following the Struts tutorial, and if I strictly follow the > tutorial "Processing forms" > https://struts.apache.org/getting-started/processing-forms, I use > Struts2-core 7.0.0 and Jetty maven plugin v11.0.25 > > The error happens because of that portion of the register.jsp code: > <s:form action="register"> > <s:textfield name="personBean.firstName" label="First name" /> > <s:textfield name="personBean.lastName" label="Last name" /> > <s:textfield name="personBean.email" label ="Email"/> > <s:textfield name="personBean.age" label="Age" /> > <s:submit/> > </s:form> > > I start from index.jsp that contains a link <a > href="register.jsp">Register</a>.
This is wrong, you must always use action instead of directly invoking JSP page https://struts.apache.org/security/#never-expose-jsp-files-directly > When I click on the link get a JasperException caused by the following one : > java.lang.NullPointerException: Cannot invoke > "java.util.List.add(Object)" because "tags" is null but there are no "tags" in your form? > So I checked out the struts-example official repo and saw that the > namespace attribute was specified > > e.g if I instead write this > <s:form action="register" namespace=""> > ........ (fields) > </s:form> > > For some reason it works. I've read the struts tag reference, and if > you don't specify the namespace it default to "current namespace". > > The exception seems to only happens when I directly link to a jsp : > Let's say I have a foo.jsp containing the same form code, and in > index.jsp I add a link to an action FooAction that just returns > foo.jsp, then the form display properly. > > So my guess is that JSP doesn't go through the mapping of struts.xml > and for some reasons using <s:form> without an attribute tag causes > this exception, but why ? I can't find a reason why and the tutorial > assumes the code shown is supposed to work, but it isn't. When you call JSP directly all the Struts machinery is omitted, always use actions Cheers Łukasz --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@struts.apache.org For additional commands, e-mail: user-h...@struts.apache.org
