securityfilter.java

利用javaEE开发而实现图书的购买的一个系统

package org.yangkang.bookshop.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;

public class SecurityFilter implements Filter {

	public void destroy() {		

	}

	public void doFilter(ServletRequest requ, ServletResponse resp,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest)requ;
		HttpServletResponse response = (HttpServletResponse)resp;
		String path = request.getContextPath();		
		if(request.getSession().getAttribute("user")==null)
		{
			response.sendRedirect(path+"/index.jsp");
		}
		else{
			chain.doFilter(request, response);
		}

	}

	public void init(FilterConfig arg0) throws ServletException {
		

	}

}