struts2.3.12中的servletactioncontext null

Question

for (Cookie cookie : ServletActionContext.getRequest().getCookies()) {

The above line is giving me

java.lang.NullPointerException
        at interceptors.RemembermeInterceptor.intercept(RemembermeInterceptor.java:35)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)

It used to work fine in struts2.1.8 I just upgraded the struts2 version in my POM.xml to 2.3.12 and it stopped working giving me the above error.

Answer 1

There are two things that could cause a NullPointerException in this line:

for (Cookie cookie : ServletActionContext.getRequest().getCookies()) {

1. ServletActionContext.getRequest() will return null if it is called outside of an HTTP request. Since you are calling that line from an interceptor, that doesn't seem likely.

2. ServletActionContext.getRequest().getCookies() will return null if there are no cookies sent with the request. Attempting to iterate over a null collection or array will produce an NPE.

Try changing your code as follows:

Cookie[] cookies = ServletActionContext.getRequest().getCookies();
if (cookies != null) {
  for (Cookie cookie : cookies) {
    // do something
  }
}