userloginfilter.java

新闻发布系统news struts+spring+hibernate

package org.yeeku.webapp.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 javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.yeeku.webapp.util.AppConstants;

/**
 * 设置字符集、过滤未登录的非法请求
 */
public class UserLoginFilter implements Filter {
	protected String encoding = null;

	protected FilterConfig filterConfig = null;

	protected boolean ignore = false;

	protected String forwardPath = null;

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

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {

		// 设置编码方式，web.xml里面有filter参数的初始化设置
		if (ignore || (request.getCharacterEncoding() == null)) {
			String encoding = selectEncoding(request);
			if (encoding != null)
				request.setCharacterEncoding(encoding);
		}
		HttpServletRequest httpServletRequest = (HttpServletRequest) request;
		HttpServletResponse httpServletResponse = (HttpServletResponse) response;
		String requesturi = httpServletRequest.getRequestURI();
		// 通过检查session中的变量，过虑请求
		HttpSession session = httpServletRequest.getSession();
		Object currentUser = session.getAttribute(AppConstants.LOGIN_USER);
		// 当前会话用户为空而且不是请求登录，退出登录，欢迎页面和根目录则退回到应用的根目录
		if (currentUser == null
				&& !requesturi.endsWith("/processLogin.do")
				&& !requesturi.endsWith("/logout.do")
				&& !requesturi.endsWith("/index.jsp")
				&& !requesturi.endsWith(httpServletRequest.getContextPath()
						+ "/")) {
			httpServletResponse.sendRedirect(httpServletRequest
					.getContextPath()
					+ "/");
			return;
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
		this.encoding = filterConfig.getInitParameter("encoding");
		this.forwardPath = filterConfig.getInitParameter("forwardpath");
		String value = filterConfig.getInitParameter("ignore");
		if (value == null)
			this.ignore = true;
		else if (value.equalsIgnoreCase("true"))
			this.ignore = true;
		else if (value.equalsIgnoreCase("yes"))
			this.ignore = true;
		else
			this.ignore = false;
	}

	protected String selectEncoding(ServletRequest request) {
		return (this.encoding);
	}
}