Struts2 parameters is coming null in action class when using Interceptors

Question

When I am using Interceptors, the values on Action class coming as null. I have removed the Interceptors, the values coming perfect from the JSP page.

Login.jsp

    <s:form id="loginFrm" name="loginFrm" action="LoginAction">  
            <s:textfield key="username"/>  
            <s:password key="password"/>  
            <s:submit/>  
    </s:form>  

LoginAction.java

public class LoginAction {  

    private static Logger LOGGER = Logger.getLogger(LoginAction.class);  

    private String username;  
    private String password;  

    public String execute() throws Exception {  
        LOGGER.info("LoginAction : authenticate()");  
        LOGGER.info("LoginAction : {[" + username + "],["+password+ "]}");  
        return "success";  
    }  

    public String getUsername() {  
        return username;  
    }  

    public void setUsername(String username) {  
        this.username = username;  
    }  

    public String getPassword() {  
        return password;  
    }  

    public void setPassword(String password) {  
        this.password = password;  
    }  
}  

web.xml

<?xml version="1.0" encoding="UTF-8"?>  
<web-app id="WebApp_9" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">  
    <display-name>Bulk Fund Switching</display-name>  
    <context-param>  
        <param-name> org.apache.tiles.impl.BasicTilesContainer.DEFINITIONS_CONFIG </param-name>  
        <param-value>/WEB-INF/tiles.xml</param-value>  
    </context-param>  
    <listener>  
        <listener-class>org.apache.struts2.tiles.StrutsTilesListener </listener-class>  
    </listener>  
    <filter>  
        <filter-name>struts2</filter-name>  
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>  
    </filter>  
    <filter-mapping>  
        <filter-name>struts2</filter-name>  
        <url-pattern>/*</url-pattern>  
    </filter-mapping>  
    <welcome-file-list>  
        <welcome-file>jsp/Login.jsp</welcome-file>  
    </welcome-file-list>  
</web-app>  

struts.xml (working version)

<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd">  
<struts>  
    <constant name="struts.enable.DynamicMethodInvocation" value="false" />  
    <constant name="struts.devMode" value="false" />  
    <constant name="struts.custom.i18n.resources" value="BFSView,BFSMessages" />  

    <package name="home-default" extends="struts-default" namespace="/">  

        <result-types>  
            <result-type name="tiles" class="org.apache.struts2.views.tiles.TilesResult" />  
        </result-types>  

        <interceptors>  
            <interceptor name="AuthenticationInterceptor" class="com.lv.bfs.controller.interceptor.AuthenticationInterceptor"></interceptor>  
            <interceptor-stack name="SecureStack">  
                <interceptor-ref name="AuthenticationInterceptor" />  
            </interceptor-stack>  
        </interceptors>  

        <action name="LoginAction" class="com.lv.bfs.controller.action.LoginAction">  
            <result name="success">jsp/Welcome.jsp</result>  
            <result name="error">/jsp/Login.jsp</result>  
        </action>  
    </package>  
</struts>  

struts.xml (Not working version )

<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd">  
<struts>  
    <constant name="struts.enable.DynamicMethodInvocation" value="false" />  
    <constant name="struts.devMode" value="false" />  
    <constant name="struts.custom.i18n.resources" value="BFSView,BFSMessages" />  

    <package name="home-default" extends="struts-default" namespace="/">  

        <result-types>  
            <result-type name="tiles" class="org.apache.struts2.views.tiles.TilesResult" />  
        </result-types>  

        <interceptors>  
            <interceptor name="AuthenticationInterceptor" class="com.lv.bfs.controller.interceptor.AuthenticationInterceptor"></interceptor>  
            <interceptor-stack name="SecureStack">  
                <interceptor-ref name="AuthenticationInterceptor" />  
            </interceptor-stack>  
        </interceptors>  

        <action name="LoginAction" class="com.lv.bfs.controller.action.LoginAction">  
            <interceptor-ref name="SecureStack"></interceptor-ref>  
            <result name="success">jsp/Welcome.jsp</result>  
            <result name="error">/jsp/Login.jsp</result>  
        </action>  
    </package>  
</struts>  

AuthenticationInterceptor.java

public class AuthenticationInterceptor extends AbstractInterceptor {  

    private static Logger LOGGER = Logger.getLogger(AuthenticationInterceptor.class);  

    private static final long serialVersionUID = 1844249996954274967L;  

    public String intercept(ActionInvocation invocation) throws Exception {  
        LOGGER.info("intercept : START");  
        return invocation.invoke();  
    }  
}  

Logs statements (both cases)

12:39:05,533 INFO  [AuthenticationInterceptor] intercept : START  
12:39:05,533 INFO  [LoginAction] LoginAction : authenticate()  
12:39:05,533 INFO  [LoginAction] LoginAction : {[null],[null]}  



12:09:05,533 INFO  [LoginAction] LoginAction : authenticate()  
12:09:05,533 INFO  [LoginAction] LoginAction : {[admin],[admin]}  

Any suggestions?

Answer 1

When you define an interceptor stack for a specific action you must define all the interceptors for that action. In this case, you are only defining your custom interceptor, meaning the "params" interceptor doesn't run, so the action properties won't be set.

Either define a new stack that includes the normal S2 interceptors, or include those interceptors (or stack) in your action configuration.