topiclistaction.java

myeclipse下mysql-struts-hibernate-tomcat一个BBS 应用

package j2eebbs.user.action;

import j2eebbs.Constants;
import j2eebbs.DB;
import j2eebbs.user.form.ForumForm;
import j2eebbs.TopicDisp;

import java.util.Vector;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.sql.DataSource;

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

public final class TopicListAction extends Action {
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {

		ForumForm forumForm = (ForumForm) form;
		int forumid = forumForm.getForumid();
		String forumname = forumForm.getForumname();
		int pageid = forumForm.getPageid();
		if (pageid < 0) {
			pageid = 0;
		}

		HttpSession session = request.getSession(true);
		Vector topicVector = new Vector();
		TopicDisp topicdisp = new TopicDisp();
		ActionMessages errors = new ActionMessages();
		String pageForward;

		ServletContext context = servlet.getServletContext();
		DataSource dataSource = (DataSource) context.getAttribute("bbsDB");
		DB db = new DB(dataSource);

		// 如果指定论坛的主题数为0
		if (topicdisp.getTopicCount(db, forumid) == 0) {
			session.setAttribute(Constants.TOPIC_LIST_KEY, topicVector);
			session.setAttribute(Constants.CUR_FORUMID_KEY,
					new Integer(forumid));
			session.setAttribute(Constants.CUR_FORUMNAME_KEY, forumname);
			session.setAttribute(Constants.CUR_PAGEID_KEY, new Integer(pageid));
			pageForward = "ToTopicList";
			// 如果到了尾页(比如说每页5条，共10条，现在到了第2页，pageid为1，
			// 后翻的话变为2，则10<11，符合此条件。若共有11条，11<11为false)
		} else if (topicdisp.getTopicCount(db, forumid) < pageid
				* Constants.TOPIC_PAGE_SIZE + 1) {
			pageid--;
			errors.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage(
					"error.topiclist.nomorepage"));
			if (!errors.isEmpty()) {
				saveErrors(request, errors);
			}
			pageForward = "ToErrorPage";
			// 如果主题数不为0，则搜索出指定论坛中指定页数的主题。
		} else {
			topicdisp.setForumid(forumid);
			topicVector = topicdisp.search(db, pageid);
			session.setAttribute(Constants.TOPIC_LIST_KEY, topicVector);
			session.setAttribute(Constants.CUR_FORUMID_KEY,
					new Integer(forumid));
			session.setAttribute(Constants.CUR_FORUMNAME_KEY, forumname);
			session.setAttribute(Constants.CUR_PAGEID_KEY, new Integer(pageid));

			pageForward = "ToTopicList";
		}

		db.close();
		return (mapping.findForward(pageForward));
	}
}