JAVA資格認證:Struts2ACTION中重定向

@Override
    public String list() throws Exception {
    HttpServletRequest request = ServletActionContext.getRequest();
    String loginName = request.getParameter("j_username");
    String password = request.getParameter("j_password");
    HttpSession session = request.getSession();
    session.setAttribute("username", loginName);
    session.setAttribute("password", password);
    //你要轉向的頁面的地址.
    String url = new String( ("../j_spring_security_check?j_username="
    +java.net.URLEncoder.encode(loginName)
    +"&j_password="+password).getBytes("UTF-8"),"ISO8859_1");
    //你要轉向的頁面的地址.
    HttpServletResponse response = ServletActionContext.getResponse();
    response.sendRedirect(url);
    //重定向后,別忘了返回null值,而不能再返回return
    //mapping.findForward("****");
    return null;
    //return SUCCESS;
    }