如何在ActionClass实现SessionAware时返回JSON对象

Question

我有一个与ajax一起使用的Action类，它返回一个JSON对象。起初我使用了一个常数值。但我决定使用会话对象：

public class ViewFlightHistoryAction extends ActionSupport implements SessionAware {
    private static final long serialVersionUID = 7325894105057499195L;
    private String viewOption;
    private List<UserBooking> bookingsList;
//  private Map<String, Object> sessionMap;

    @Override
    public String execute() throws Exception {
        bookingsList = getBookingsList(viewOption);

        return SUCCESS;
    }

    private List<UserBooking> getBookingsList(String viewOption) throws Exception {
//      Map<String, Object> session = ActionContext.getContext().getSession();
        Customer customer = (Customer) sessionMap.get("customer");
        BookingManager bookingManager = new BookingManager();
        List<UserBooking> userBookingsList  = new LinkedList<UserBooking>();
        String previousFlights = "Previous Flights";
        String currentFlights = "Current Flights";


        if (previousFlights.equalsIgnoreCase(viewOption)) {
            // Replace parameter with session user's ID
            userBookingsList = bookingManager.getPreviousBookingsList(customer.getCustomerID());
        } else if (currentFlights.equalsIgnoreCase(viewOption)) {
            userBookingsList = bookingManager.getCurrentBookingsList(customer.getCustomerID());
        }

        return userBookingsList;
    }

    public String getViewOption() {
        return viewOption;
    }

    public void setViewOption(String viewOption) {
        this.viewOption = viewOption;
    }

    public List<UserBooking> getBookingsList() {
        return bookingsList;
    }

    public void setBookingsList(List<UserBooking> bookingsList) {
        this.bookingsList = bookingsList;
    }

    @Override
    public void setSession(Map<String, Object> sessionMap) {
        this.sessionMap = sessionMap;
    }

}

这是我对ajax的jQuery：

function viewFlightsWithAjax($viewOption) {
    $.ajax({
        type:"POST",
        url:"viewFlightHistory",
        async:true,
        data: {viewOption: $viewOption},
        dataType:"json",
        success: function(jsonObject) {
            var bookingsList = jsonObject.bookingsList;
            for (var i = 0; i < bookingsList.length; i++) {
                var booking = bookingsList[i]; 
                var bookingID = booking.bookingID; 
                var bookingFlightDate = booking.flightDate; 
                bookingFlightDate = toLocaleDate(bookingFlightDate);
                var bookingOrigin = booking.origin; 
                var bookingDestination = booking.destination; 

                var bookingRow = "<tr>" 
                                + "<td>" + bookingID + "</td>"  
                                + "<td>" + bookingFlightDate + "</td>"
                                + "<td>" + bookingOrigin + "</td>"
                                + "<td>" + bookingDestination + "</td>"
                                + "<td>Receipt#</td>"
                                + "<td>Itenerary Details</td>"
                                + "</tr>";
                $("#bookingTable tbody").append(bookingRow);
            }
        }
    });
}

无论如何，我的问题是，当我开始实现SessionAware并使用会话对象时，它就不再起作用了。我调试它，bookingsList属性确实检索它不返回它的值。在我的struts.xml中，我排除了sessionMap和viewOption，但它似乎仍然没有返回JSON值。如何检索JSON对象？

编辑：我使用了这个拦截器：

package com.bootcamp.skyjuander.system.interceptors;

import java.util.Map;

import com.bootcamp.skyjuander.service.user.beans.Customer;
import com.bootcamp.skyjuander.system.actions.ViewFlightHistoryAction;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class ViewFlightHistoryInterceptor extends AbstractInterceptor {

    /**
     * 
     */
    private static final long serialVersionUID = -9003400922950846927L;

    @Override
    public String intercept(ActionInvocation invocation) throws Exception {
        ViewFlightHistoryAction action = (ViewFlightHistoryAction) invocation.getAction();
        Map<String, Object> sessionMap = ActionContext.getContext().getSession();
        // Customer customer
        Customer sessionCustomer = (Customer) sessionMap.get("customer");

        action.setCustomer(sessionCustomer);


        String result = invocation.invoke();

        return result;
    }


}