1     
2    import javax.servlet.http.HttpServlet; 
3    import javax.servlet.http.HttpServletRequest; 
4    import javax.servlet.http.HttpServletResponse; 
5    import java.io.BufferedInputStream; 
6    import java.io.IOException; 
7    import java.io.InputStream; 
8    import java.io.PrintWriter; 
9    import java.util.zip.GZIPInputStream; 
10    
11   /** 
12    * @author Julius Davies 
13    * @author http://juliusdavies.ca/ 
14    * @since 22-Mar-2006 
15    */ 
16   public class GZIPServlet extends HttpServlet 
17   { 
18      public void doPost( HttpServletRequest req, HttpServletResponse res ) 
19            throws IOException 
20      { 
21         // This servlet just unzips a POST with gzip Content-Encoding, 
22         // prints off the first 4KB (unzipped) in the response, and 
23         // reports the total unzipped size. 
24          
25         res.setContentType( "text/plain" ); 
26         res.setCharacterEncoding( "UTF-8" ); 
27         PrintWriter writer = res.getWriter(); 
28    
29         String contentEncoding = req.getHeader( "Content-Encoding" ); 
30         boolean isGzip = false; 
31         if ( contentEncoding != null ) 
32         { 
33            isGzip = "gzip".equalsIgnoreCase( contentEncoding.trim() ); 
34         } 
35         if ( isGzip ) 
36         { 
37            InputStream in = req.getInputStream(); 
38            in = new BufferedInputStream( in ); 
39            in = new GZIPInputStream( in ); 
40    
41            StringBuffer buf = new StringBuffer( 4096 ); 
42            int c = in.read(); 
43            int count = 0; 
44            while ( c >= 0 ) 
45            { 
46               count++; 
47               byte b = (byte) c; 
48               if ( count <= 4096 ) 
49               { 
50                  buf.append( (char) b ); 
51               } 
52               c = in.read(); 
53            } 
54    
55            writer.println( "First 4KB: " ); 
56            writer.println( "-------------------------------------------" ); 
57            writer.println( buf.toString() ); 
58            writer.println( "-------------------------------------------" ); 
59            writer.println( "Content unzipped to " + count + " bytes." ); 
60         } 
61         else 
62         { 
63            writer.println( "Content-Encoding is not gzip!" ); 
64            writer.println( "-------------------------------------------" ); 
65            writer.println( "Content-Encoding: [" + contentEncoding + "]" ); 
66         } 
67    
68         writer.close(); 
69      } 
70    
71    
72   } 
73