Java编程

开发平台：
Java

LookNoteAction.java：源码内容
							package StudyNote;
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;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;
import javax.servlet.ServletContext;
import javax.sql.DataSource;
import java.sql.Connection;
import javax.servlet.http.*;
import java.util.*;
import org.apache.struts.action.DynaActionForm;
public final class LookNoteAction extends Action{  
	public ActionForward execute(
		ActionMapping mapping,
		ActionForm form,
		HttpServletRequest request,  
		HttpServletResponse response) throws Exception {
	
		DynaActionForm pageIdForm = (DynaActionForm) form;         
		Integer pageId = (Integer)pageIdForm.get("pageId");
		int iPageId = 0;
		if (pageId!=null) iPageId = pageId.intValue();
		if (iPageId<0) iPageId = 0;
   		ServletContext context = servlet.getServletContext();
		DataSource dataSource = (DataSource)context.getAttribute(Constants.DATASOURCE_KEY);
						
        DB db = new DB(dataSource);
        HttpSession session = request.getSession(true);
		Vector noteList = new Vector();
        int noteCount = Note.GetNoteCount(db);
		int iPageCount;
		if (noteCount%Constants.NOTE_PAGE_SIZE==0) {
			iPageCount = noteCount/Constants.NOTE_PAGE_SIZE;
		}
		else{
			iPageCount = noteCount/Constants.NOTE_PAGE_SIZE+1;
		}
		String PageForward;
		ActionMessages errors = new ActionMessages();
		
		
   		String username=(String)session.getAttribute(Constants.LOGIN_USERNAME_KEY);
        
		if (username==null){
            errors.add(ActionMessages.GLOBAL_MESSAGE,
                           new ActionMessage("errors.accessDeny"));
			if (!errors.isEmpty()) {
				saveErrors(request, errors);
			} 
 			PageForward="toWrong";  
		}
        else if (noteCount==0){
			session.setAttribute(Constants.NOTE_LIST_KEY,noteList);
			session.setAttribute(Constants.CUR_PAGEID_KEY,new Integer(iPageId));
			session.setAttribute(Constants.NOTE_PAGE_COUNT_KEY,new Integer(iPageCount));
  			PageForward="toNoteMain";  
        }
        else if (noteCount<iPageId * Constants.NOTE_PAGE_SIZE + 1){
        	iPageId--;
            errors.add(ActionMessages.GLOBAL_MESSAGE,
                           new ActionMessage("errors.pageEnd"));
			if (!errors.isEmpty()) {
				saveErrors(request, errors);
			} 
 			PageForward="toWrong";  
		}
		else{
			noteList = Note.SearchNoteTitle(db,iPageId);
			session.setAttribute(Constants.NOTE_LIST_KEY,noteList);
			session.setAttribute(Constants.CUR_PAGEID_KEY,new Integer(iPageId));
			session.setAttribute(Constants.NOTE_PAGE_COUNT_KEY,new Integer(iPageCount));
  			PageForward="toNoteMain";  
       }
        
		db.close();
 	  	return  mapping.findForward(PageForward);  
	}
}

						