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1
18 package filters.gzip;
19
20 import java.io.IOException  ;
21 import java.util.Enumeration ;
22
23 import javax.servlet.Filter ;
24 import javax.servlet.FilterChain ;
25 import javax.servlet.FilterConfig ;
26 import javax.servlet.ServletContext ;
27 import javax.servlet.ServletException ;
28 import javax.servlet.ServletRequest ;
29 import javax.servlet.ServletResponse ;
30 import javax.servlet.http.HttpServletRequest ;
31 import javax.servlet.http.HttpServletResponse ;
32
33
40 public class GzipFilter implements Filter {
41
42 private static final String ACCEPT_ENCODING = "Accept-Encoding";
43
44 private ServletContext context;
45
46 public void init(FilterConfig config) throws ServletException {
47 this.context = config.getServletContext();
48 }
49
50 public void destroy() {
51 this.context = null;
52 }
53
54 public void doFilter(ServletRequest request, ServletResponse response,
55 FilterChain chain) throws IOException , ServletException {
56 Enumeration headers = ((HttpServletRequest ) request).getHeaders(ACCEPT_ENCODING);
57 boolean acceptsGzipEncoding = false;
58 while (headers.hasMoreElements() && !acceptsGzipEncoding) {
59 acceptsGzipEncoding = (((String ) headers.nextElement()).indexOf("gzip") != -1);
60 }
61 if (acceptsGzipEncoding) {
62 GzipResponseWrapper encodedResponse = new GzipResponseWrapper(
63 (HttpServletResponse ) response, this.context);
64 chain.doFilter(request, encodedResponse);
65 encodedResponse.close();
66 } else {
67 chain.doFilter(request, response);
68 }
69 }
70 }
71 |
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