checkfilter.java

1.员工添加 2.人事调动 3.在职人员管理 4.部门（分厂）管理

package pmsys;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
 * 实例9-2
 * 
 * 先执行http://localhost:7878/JSPCH09/auth/test.jsp
 * 其中/auth下的资源为受保护的资源; 如果用户未登陆那么直接跳转的登陆页面loginPage.jsp;
 * 在用户登陆完成后再显示/auth/test.jsp的内容
 * 
 * login.jsp用于判断权限
 * 
 * @author java
 *
 */
public class CheckFilter implements Filter {
	private FilterConfig filterConfig;

	private String loginPage = "/pmsys/login.jsp";

	public void destroy() {
		this.filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse reponse,
			FilterChain chain) throws IOException, ServletException {
		
        HttpServletRequest req = (HttpServletRequest)request;
        HttpServletResponse res = (HttpServletResponse)reponse;
        
        HttpSession session = req.getSession();
        //判断用户是否登陆成功
        if(session.getAttribute("flages")!=null){
        	chain.doFilter(req, res);
        	//return;
        }else{
        	ServletContext ctx = this.filterConfig.getServletContext();
        	setForwardURI(req);
        	ctx.getRequestDispatcher(loginPage).forward(req, res);
        }
	}

	/**
	 * 从web.xml中读取配置信息
	 */
	public void init(FilterConfig config) throws ServletException {
		this.filterConfig = config;
		if (filterConfig.getInitParameter("loginPage") != null) {
			loginPage = filterConfig.getInitParameter("loginPage");
		}

	}  
	//设置原始请求的请求 URL
	private void setForwardURI(HttpServletRequest request){
		//获得请求的资源  如果客户请求 http://localhost:7878/jsp09/a.jsp?id=20
		//以下方法得到的是/jsp09/a.jsp 注意不包含？后的查询字符串
		StringBuffer requestURI = new StringBuffer(request.getRequestURI());
		
		//以下方法获得查询字符串，就是问好后面的内容
		String queryString = request.getQueryString();
		
		//组装完整的请求路径
		if(queryString != null){
			requestURI.append("?").append(queryString);
		}
		request.setAttribute("orignURL", requestURI.toString());
	}

}