java使用Filter实现全栈压缩

在服务器向浏览器响应数据的时候，对响应的数据进行压缩，便于传输和提升效率。
实现思路：
1、拦截所有请求
2、获取写出的内容
3、对写出的内容进行压缩
4、将压缩内容返回给浏览器
采用的压缩格式为gzip，浏览器支持。
过滤器:

/** * Servlet Filter implementation class GlobalGzipFilter * 实现的全栈压缩 */@WebFilter("/*")public class GlobalGzipFilter implements Filter {    /**     * Default constructor.      */    public GlobalGzipFilter() {        // TODO Auto-generated constructor stub    }    /**     * @see Filter#destroy()     */    public void destroy() {        // TODO Auto-generated method stub    }    /**     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)     */    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {        // TODO Auto-generated method stub        // 重构响应对象        GzipResponse rsp=new GzipResponse((HttpServletResponse)response, new ByteArrayOutputStream());        // pass the request along the filter chain        chain.doFilter(request, rsp);        //获取响应的内容        ByteArrayOutputStream baos=rsp.getOutStream();        System.out.println("压缩之前："+baos.size()+"字节");        //开始压缩        //创建内存流对象，存储压缩之后的的内容        ByteArrayOutputStream newbaos=new ByteArrayOutputStream();        GZIPOutputStream gzip=new GZIPOutputStream(newbaos);        gzip.write(baos.toByteArray());        gzip.flush();        gzip.close();        System.out.println("压缩之后："+newbaos.size()+"字节");        HttpServletResponse resp=(HttpServletResponse)response;        //设置消息头，标记内容为gzip        resp.setHeader("Content-Encoding", "gzip");resp.getOutputStream().write(newbaos.toByteArray());//写出真正的内容       }    /**     * @see Filter#init(FilterConfig)     */    public void init(FilterConfig fConfig) throws ServletException {        // TODO Auto-generated method stub    }    //自定义的响应对象    private class GzipResponse extends HttpServletResponseWrapper{        private ByteArrayOutputStream baos;//内存输出字节流        private PrintWriter pw;        public GzipResponse(HttpServletResponse response,ByteArrayOutputStream baos) {            super(response);            this.baos=baos;            // TODO Auto-generated constructor stub        }        //获取响应内容的内存流对象，存储着要响应的数据        public ByteArrayOutputStream getOutStream(){            // TODO Auto-generated method stub            if(pw!=null){                pw.flush();            }            return baos;        }        @Override        public PrintWriter getWriter() throws IOException {            //将响应的内容写出到指定的内存流中            pw=new PrintWriter(new OutputStreamWriter(baos,"UTF-8"));            return pw;        }    }}