Java web應用用戶是否登錄驗證過濾處理機制

1、web.xml

<filter>
	<filter-name>simpleLoginFilter</filter-name>
	<filter-class>com.auth.service.MySimpleLoginFilter</filter-class>
</filter>

<filter-mapping>
	<filter-name>simpleLoginFilter</filter-name>
	<url-pattern>/*</url-pattern>
</filter-mapping>

2、添加過濾器

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 com.auth.domain.model.User;
import com.common.constant.SystemInfo;

public class MySimpleLoginFilter implements Filter {

	/*
	 * (non Javadoc)
	 * 
	 * @Title: destroy
	 * 
	 * @see javax.servlet.Filter#destroy()
	 */
	public void destroy() {
	}

	/*
	 * (non Javadoc)
	 * 
	 * @Title: doFilter
	 * 
	 * @param arg0
	 * 
	 * @param arg1
	 * 
	 * @param arg2
	 * 
	 * @throws IOException
	 * 
	 * @throws ServletException
	 * 
	 * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest,
	 * javax.servlet.ServletResponse, javax.servlet.FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request;
		HttpSession session = req.getSession();

		// 由於web.xml中設置Filter過濾全部請求，可以排除不需要過濾的url
		String requestURI = req.getRequestURI();
		if (requestURI.endsWith("index.jsp") 
				|| requestURI.endsWith("login.jsp") 
				|| requestURI.endsWith("login.gb")
				|| requestURI.endsWith("loginWithToken.gb")
				|| requestURI.endsWith(".png") 
				|| requestURI.endsWith(".js")
				|| requestURI.endsWith(".css") 
				|| requestURI.endsWith(".json")
				|| requestURI.contains("/services/")
				|| requestURI.contains("/rest/")
				|| requestURI.contains("/common/")) {
			chain.doFilter(request, response);
			return;
		}

		// 判斷用戶是否登錄，進行頁面的處理
		if (requestURI.endsWith("loginFail.gb")) {
			((HttpServletResponse) response).sendRedirect("index.jsp?error="
					+ request.getParameter("error"));
			return;
		} else if (requestURI.equals("/scms/") || null == session.getAttribute(SystemInfo.SESSION_USER)
				|| ((User) session.getAttribute(SystemInfo.SESSION_USER))
						.getId() == null) {
			// 未登錄用戶，重定向到登錄頁面
			((HttpServletResponse) response).sendRedirect("/scms/index.jsp");
			return;
		} else {
//			if (requestURI.equals("/scms/")) {
//				((HttpServletResponse) response)
//						.sendRedirect("businessIndex.gb");
//				return;
//			}
			// 已登錄用戶，允許訪問
			chain.doFilter(request, response);
		}
	}

	/*
	 * (non Javadoc)
	 * 
	 * @Title: init
	 * 
	 * @param arg0
	 * 
	 * @throws ServletException
	 * 
	 * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
	 */
	public void init(FilterConfig arg0) throws ServletException {
	}

}