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