themeselectaction.java

J2EE电子商务系统开发从入门到精通---基于Struts和Hibernate技术实现

/*
 * ThemeInitAction.java
 *
 * Created on 2006年8月19日, 上午9:31
 */

package action.vote;

import javax.servlet.http.*;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForward;
import java.util.*;
import model.vote.hibernate.*;
/**
 *
 * @author Administrator
 * @version
 */

public class ThemeSelectAction extends Action {
    
    /* forward name="success" path="" */
    private final static String SUCCESS = "success";
    
    /**
     * This is the action called from the Struts framework.
     * @param mapping The ActionMapping used to select this instance.
     * @param form The optional ActionForm bean for this request.
     * @param request The HTTP Request we are processing.
     * @param response The HTTP Response we are processing.
     * @throws java.lang.Exception
     * @return
     */
    public ActionForward execute(ActionMapping mapping, ActionForm  form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        // 从用户Http请求中得到参数themeid的值，即当前议题信息的编号
        String id = request.getParameter("themeid");
        
        // 根据编号，从数据库读取对应的议题信息
        Theme theme = ThemeUtil.find(id);
        if (theme == null) {
            return new ActionForward(mapping.getInput());
        }
        
        // 根据议题编号，从数据库读取对应议题中的选项信息
        List list = ChoiceUtil.findAll(id);
        if (list == null) {
            return new ActionForward(mapping.getInput());
        }
        
        // 获得HttpSession缓存
        HttpSession httpSession = request.getSession();
        // 将议题信息存入缓存
        httpSession.setAttribute("theme", theme);
        // 将议题选项信息存入缓存
        httpSession.setAttribute("choicelist", list);
        
        return mapping.findForward(SUCCESS);
    }
}