documentselectaction.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

/*
 * DocumentIdAction.java
 *
 * Created on 2006年9月6日, 下午11:41
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package action.library;

import form.library.DocumentForm;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import model.library.hibernate.Document;
import model.library.hibernate.DocumentUtil;

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
 */
public class DocumentSelectAction 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，即当前的文档编号
        String id = request.getParameter("id");
        
        // 根据编号，从数据库读取对应的文档信息
        Document doc = DocumentUtil.find(id);
        if (doc == null) {
            return new ActionForward(mapping.getInput());
        }
        
        // 获得HttpSession缓存
        HttpSession httpSession = request.getSession();
        // 将文档信息存入缓存
        httpSession.setAttribute("document", doc);
        
        return mapping.findForward(SUCCESS);
    }    
}