gzipfilter.java.svn-base

EasyJWeb是基于java技术

package com.easyjf.web;

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;

/**
 * the gzipfilter
 * 
 * @author wlr
 * 
 */
public class GZIPFilter implements Filter {

	public void doFilter(ServletRequest req, ServletResponse res,
			FilterChain chain) throws IOException, ServletException {
		if (req instanceof HttpServletRequest) {
			HttpServletRequest request = (HttpServletRequest) req;
			HttpServletResponse response = (HttpServletResponse) res;
			String ae = request.getHeader("accept-encoding");
			if ((ae != null && ae.indexOf("gzip") != -1)) {
				// Vary: Accept-Encoding
				// System.out.println("GZIP 支持, 压缩文件中");
				GZIPResponseWrapper wrappedResponse = new GZIPResponseWrapper(
						response);
				chain.doFilter(req, wrappedResponse);
				wrappedResponse.finishResponse();
				return;
			}
			chain.doFilter(req, res);
		}
	}

	public void init(FilterConfig filterConfig) {
	}

	public void destroy() {
	}
}