topicdeleteaction.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

/*
 * TopicDeleteAction.java
 *
 * Created on 2006年6月15日, 上午2:45
 */

package action.bbs;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import model.bbs.hibernate.TopicUtil;
import java.util.*;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForward;
/**
 *
 * @author Administrator
 * @version
 */

public class TopicDeleteAction 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id的值，即当前的主题编号
        String id = request.getParameter("id");
        
        // 删除数据库中编号为id的主题信息
        boolean isSuccess = TopicUtil.delete(id);
        ActionForward actionForward = null;
        if (isSuccess == true) {
            return new ActionForward(mapping.getInput());
        }

		// 从数据库读取当前所有的主题空间信息
        List list = TopicUtil.findAll();
        if (list == null) {
            return new ActionForward(mapping.getInput());
        }

        // 获得HttpSession缓存
        HttpSession httpSession = request.getSession();
        // 将查询得到的所有主题空间信息存入缓存
        httpSession.setAttribute("topiclist", list);
        
        return mapping.findForward(SUCCESS);
    }
}