登录拦截器（自定义拦截器）清除操作参数

Question

Here is the interceptor code:-

public class LoginInterceptor extends AbstractInterceptor implements
    StrutsStatics {
/**
 * 
 */
private static final long serialVersionUID = 1L;

@Override
public String intercept(ActionInvocation invocation) throws Exception {
    ActionContext context = invocation.getInvocationContext();
    HttpServletRequest request = (HttpServletRequest) context
            .get(HTTP_REQUEST);
    HttpSession session = request.getSession(false);

    String loginId = (String) session
            .getAttribute(Constants.SESSION_ATT_USERID);

    if (loginId == null) {
        return Action.LOGIN;
    } else {
        return invocation.invoke();
    }

}
}

When calling any particular Action the Interceptor is been called. But the parameters of the Action is getting null. If running the code without interceptor, then its working fine. I tried resolving this from many ways but couldn't find any solution.

Answer 1

When you want to use an Interceptor, you need to ADD it to the defaultStack, or to a customStack of your, while you have most likely used ONLY that Interceptor for your action. This means that any other Interceptor is not running for that action invocation, not even the Parameter Interceptor, that is responsible for setting the parameters in the action.

Wrong:

<action name="foo" class="org.foo.bar.foobarAction">

    <interceptor-ref name="myLoginInterceptor"/>

    <result>success.jsp</result>
</action>

Right:

<action name="foo" class="org.foo.bar.foobarAction">

    <interceptor-ref name="myLoginInterceptor"/>
    <interceptor-ref name="defaultStack"/>

    <result>success.jsp</result>
</action>