listannouncefilter.java

java web网络编程示例,原代码资源

package edu.liusong.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import edu.liusong.dao.BoardDAO;
import edu.liusong.dao.NewsDAO;

public class ListAnnounceFilter implements Filter {

	protected FilterConfig config = null;

	public void destroy() {
		config = null;
	}

	public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException,
			ServletException {
		HttpServletRequest request = (HttpServletRequest) arg0;
		if (request.getAttribute("boardList") == null) {
			// 左边导航栏信息初始化
			request.setAttribute("boardList", new BoardDAO().getBoards());
		}
		if (request.getAttribute("newsList") == null) {
			// 右侧通知初始化
			request.setAttribute("newsList", new NewsDAO().getTopNews());
		}
		/** 分页初始化 * */

		int pageSize = Integer.parseInt(config.getInitParameter("pageSize"));
		int topage;
		String strpage = request.getParameter("strpage");
		if (strpage == null) {
			topage = 1;
		} else {
			topage = Integer.parseInt(strpage);
			if (topage < 1)
				topage = 1;
		}
		request.setAttribute("announceList", new NewsDAO().getByPage(pageSize, topage));
		request.setAttribute("prePage", topage - 1);
		request.setAttribute("nextPage", topage + 1);
		arg2.doFilter(arg0, arg1);
	}

	public void init(FilterConfig arg0) throws ServletException {
		config = arg0;
	}

}