editbookaction.java

来自「beginJsp2.0外文书籍源代码」· Java 代码 · 共 40 行

package com.wrox.publish.action;

import com.wrox.publish.bo.BookBO;
import com.wrox.publish.om.Book;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

/**
 * Struts Action invoked when the user wants to edit a Book. Retrieves
 * the Book object with an id passed in through the ActionForm from
 * the database, then binds it in the session as the new ActionForm.
 */
public class EditBookAction extends Action {
    /** 
     * Invoked by the Struts controller.
     * @param mapping The ActionMapping invoking this Action.
     * @param form The ActionForm. This <em>must</em> be a Book with
     *  a valid <code>id</code>.
     * @param request The HTTP request.
     * @param response The HTTP response.
     * @return the ActionForward item labelled "success".
     */    
    public ActionForward execute(ActionMapping mapping, 
                                 ActionForm form,
                                 HttpServletRequest request, 
                                 HttpServletResponse response) 
    throws Exception {
        BookBO bookBO = BookBO.getInstance(request, getDataSource(request));
        Book book = bookBO.findBookById(((Book)form).getId());
        request.getSession().setAttribute(mapping.getName(), book);
        return mapping.findForward("success");
    }
}