war/src/main/java/pnews/servlet/Pnews.java

   1 package pnews.servlet;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.io.InputStreamReader;
   6 import java.io.Reader;
   7 import java.io.UnsupportedEncodingException;
   8 import java.io.Writer;
   9 import java.net.URLDecoder;
  10 import java.util.ArrayList;
  11 import java.util.List;
  12 import java.util.logging.Level;
  13 import java.util.logging.Logger;
  14
  15 import javax.servlet.ServletConfig;
  16 import javax.servlet.ServletException;
  17 import javax.servlet.http.HttpServlet;
  18 import javax.servlet.http.HttpServletRequest;
  19 import javax.servlet.http.HttpServletResponse;
  20
  21 import com.rometools.rome.io.FeedException;
  22
  23 import pnews.Article;
  24 import pnews.Category;
  25
  26 public class Pnews extends HttpServlet {
  27         private static final String CLASS_NAME = Pnews.class.getName();
  28         private static final Logger LOG = Logger.getLogger(Pnews.class.getName());
  29         private static final long serialVersionUID = 1L;
  30         private static final ArticleProvider provider = ArticleProvider.singleton;
  31
  32         private static String getQueryParameter(HttpServletRequest rq, String key)
  33                         throws UnsupportedEncodingException {
  34                 final String METHOD_NAME="getQueryParameter";
  35                 String[] params;
  36                 int idx;
  37                 String q;
  38
  39
  40                 LOG.entering(CLASS_NAME, METHOD_NAME, new Object[] { rq, key} );
  41
  42                 q = rq.getQueryString();
  43
  44                 if (q == null)
  45                         return null;
  46
  47                 params = q.split("&");
  48
  49                 for (String p: params) {
  50                         idx = p.indexOf('=');
  51
  52                         if (idx > 1 && p.substring(0, idx).equals(key))
  53                                 return URLDecoder.decode(p.substring(idx + 1), "UTF-8");
  54                 }
  55
  56                 return null;
  57         }
  58
  59         private static void redirect(HttpServletRequest rq, HttpServletResponse rp) {
  60                 String redirectURL;
  61                 Article a;
  62
  63                 LOG.entering(Pnews.class.getName(), "redirect", new Object[] { rq, rp });
  64
  65                 try {
  66                         redirectURL = getQueryParameter(rq, "url");
  67
  68                         LOG.info("Request redirection to " + redirectURL);
  69
  70                         if (redirectURL != null) {
  71                                 a = ArticleStore.singleton.get(redirectURL);
  72                                 if (a != null)
  73                                         a.readCount.incrementAndGet();
  74                                 else
  75                                         LOG.severe("Cannot find the article " + redirectURL);
  76
  77                                 rp.setHeader("Location", redirectURL);
  78                                 rp.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
  79                         } else {
  80                                 LOG.severe("No redirection URL");
  81                                 rp.setStatus(HttpServletResponse.SC_NOT_FOUND);
  82                         }
  83
  84                 } catch (UnsupportedEncodingException e) {
  85                         e.printStackTrace();
  86                         LOG.log(Level.SEVERE, "redirect failure", e);
  87                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
  88                 }
  89
  90                 LOG.exiting(Pnews.class.getName(), "redirect");
  91         }
  92
  93         private void writeStats(HttpServletResponse rp) throws IOException {
  94                 rp.setContentType("application/json;charset=utf-8");
  95                 rp.setCharacterEncoding("utf-8");
  96
  97                 rp.getWriter().write(JSON.getStats());
  98         }
  99
 100
 101         private void writeArticles(Category cat, HttpServletResponse rp) {
 102                 String html;
 103                 List<Article> articles;
 104
 105                 try {
 106                         articles = provider.getArticles(cat);
 107                         if (articles != null) {
 108                                 html = HTML.toHTML(articles, cat);
 109                                 rp.setContentType("text/html;charset=utf-8");
 110                                 rp.getWriter().write(html);
 111                                 rp.setCharacterEncoding("utf-8");
 112                         } else {
 113                                 LOG.severe("writeArticles cannot retrieve any articles");
 114                                 html = HTML.toHTML(new ArrayList<Article>(), cat);
 115                                 rp.setContentType("text/html");
 116                                 rp.getWriter().write(html);
 117                         }
 118                 } catch (IOException | IllegalArgumentException | FeedException e) {
 119                         LOG.log(Level.SEVERE, "writeArticles failure", e);
 120                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 121                 }
 122         }
 123
 124         private void copy(InputStream in, Writer writer) throws IOException {
 125                 Reader r;
 126                 char[] buf;
 127                 int n;
 128
 129                 buf = new char[1024];
 130                 r = new InputStreamReader(in);
 131                 while ( (n = r.read(buf, 0, buf.length)) != -1)
 132                         writer.write(buf, 0, n);
 133         }
 134
 135         @Override
 136         protected void doGet(HttpServletRequest req, HttpServletResponse resp) {
 137                 final String METHOD_NAME = "doGet";
 138                 String path;
 139                 InputStream in;
 140
 141                 RequesterLog.singleton.writeRequest(req);
 142
 143                 LOG.info("doGet " + req.getRemoteAddr().toString() + " " + req.getRequestURI() + " " + req.getQueryString());
 144
 145                 LOG.info(METHOD_NAME + " queryString=" + req.getQueryString());
 146
 147                 path = req.getPathInfo();
 148
 149                 if (path.equals("/redirect")) {
 150                         redirect(req, resp);
 151                         return ;
 152                 }
 153
 154                 if (path.equals("/style.css")) {
 155                         try {
 156                                 in = HTML.class.getClassLoader().getResourceAsStream("style.css");
 157                                 copy(in, resp.getWriter());
 158                                 resp.setContentType("text/css");
 159
 160                                 return ;
 161                         } catch (IOException e) {
 162                                 LOG.log(Level.SEVERE, "doGet failure", e);
 163                                 resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 164
 165                                 return ;
 166                         }
 167                 }
 168
 169                 if (path.equals("/")) {
 170                         writeArticles(Category.TOP, resp);
 171                         return ;
 172                 }
 173
 174                 try {
 175
 176                         if (path.equals("/stats")) {
 177                                 writeStats(resp);
 178                                 return ;
 179                         }
 180
 181                         for (Category cat: Category.values()) {
 182                                 if (path.equals('/' + cat.getId())) {
 183                                         writeArticles(cat, resp);
 184                                         return ;
 185                                 }
 186                         }
 187
 188                         resp.getWriter().write("Not found " + req.getPathInfo());
 189                         resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
 190                 } catch (IOException e) {
 191                         LOG.log(Level.SEVERE, "doGet failure", e);
 192                         resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 193                 }
 194         }
 195
 196         @Override
 197         public void init(ServletConfig config) throws ServletException {
 198                 LOG.info("Pnews servlet init " + config.getServletContext().getContextPath());
 199
 200         }
 201 }