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
  27 public class Pnews extends HttpServlet {
  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                 String[] params;
  35                 int idx;
  36                 String q;
  37
  38                 q = rq.getQueryString();
  39
  40                 if (q == null)
  41                         return null;
  42
  43                 params = URLDecoder.decode(q, "UTF-8").split("&");
  44
  45                 for (String p: params) {
  46                         idx = p.indexOf('=');
  47
  48                         if (idx > 1 && p.substring(0, idx).equals(key))
  49                                 return p.substring(idx + 1);
  50                 }
  51
  52                 return null;
  53         }
  54
  55         private static void redirect(HttpServletRequest rq, HttpServletResponse rp) {
  56                 String redirectURL;
  57                 Article a;
  58
  59                 LOG.entering(Pnews.class.getName(), "redirect");
  60
  61                 try {
  62                         redirectURL = getQueryParameter(rq, "url");
  63
  64                         LOG.info("Request redirection to " + redirectURL);
  65
  66                         if (redirectURL != null) {
  67                                 a = ArticleStore.singleton.get(redirectURL);
  68                                 if (a != null)
  69                                         a.readCount.incrementAndGet();
  70                                 else
  71                                         LOG.severe("Cannot find the article " + redirectURL);
  72
  73                                 rp.setHeader("Location", redirectURL);
  74                                 rp.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
  75                         } else {
  76                                 LOG.severe("No redirection URL");
  77                                 rp.setStatus(HttpServletResponse.SC_NOT_FOUND);
  78                         }
  79
  80                 } catch (UnsupportedEncodingException e) {
  81                         e.printStackTrace();
  82                         LOG.log(Level.SEVERE, "redirect failure", e);
  83                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
  84                 }
  85
  86                 LOG.exiting(Pnews.class.getName(), "redirect");
  87         }
  88
  89         private void writeStats(HttpServletResponse rp) throws IOException {
  90                 rp.setContentType("text/html;charset=utf-8");
  91                 rp.setCharacterEncoding("utf8-8");
  92
  93                 rp.getWriter().write("" + ArticleStore.singleton);
  94         }
  95
  96
  97         private void writeArticles(Category cat, HttpServletResponse rp) {
  98                 String html;
  99                 List<Article> articles;
 100
 101                 try {
 102                         articles = provider.getArticles(cat);
 103                         if (articles != null) {
 104                                 html = HTML.toHTML(articles, cat);
 105                                 rp.setContentType("text/html;charset=utf-8");
 106                                 rp.getWriter().write(html);
 107                                 rp.setCharacterEncoding("utf8-8");
 108                         } else {
 109                                 LOG.severe("writeArticles cannot retrieve any articles");
 110                                 html = HTML.toHTML(new ArrayList<Article>(), cat);
 111                                 rp.setContentType("text/html");
 112                                 rp.getWriter().write(html);
 113                         }
 114                 } catch (IOException | IllegalArgumentException | FeedException e) {
 115                         LOG.log(Level.SEVERE, "writeArticles failure", e);
 116                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 117                 }
 118         }
 119
 120         private void copy(InputStream in, Writer writer) throws IOException {
 121                 Reader r;
 122                 char[] buf;
 123                 int n;
 124
 125                 buf = new char[1024];
 126                 r = new InputStreamReader(in);
 127                 while ( (n = r.read(buf, 0, buf.length)) != -1)
 128                         writer.write(buf, 0, n);
 129         }
 130
 131         @Override
 132         protected void doGet(HttpServletRequest req, HttpServletResponse resp) {
 133                 String path;
 134                 InputStream in;
 135
 136                 RequesterLog.singleton.writeRequest(req);
 137
 138                 LOG.info("doGet " + req.getRemoteAddr().toString() + " " + req.getRequestURI() + " " + req.getQueryString());
 139
 140                 path = req.getPathInfo();
 141
 142                 if (path.equals("/redirect")) {
 143                         redirect(req, resp);
 144                         return ;
 145                 }
 146
 147                 if (path.equals("/style.css")) {
 148                         try {
 149                                 in = HTML.class.getClassLoader().getResourceAsStream("style.css");
 150                                 copy(in, resp.getWriter());
 151                                 resp.setContentType("text/css");
 152
 153                                 return ;
 154                         } catch (IOException e) {
 155                                 LOG.log(Level.SEVERE, "doGet failure", e);
 156                                 resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 157
 158                                 return ;
 159                         }
 160                 }
 161
 162                 if (path.equals("/")) {
 163                         writeArticles(Category.TOP, resp);
 164                         return ;
 165                 }
 166
 167                 try {
 168
 169                         if (path.equals("/stats")) {
 170                                 writeStats(resp);
 171                                 return ;
 172                         }
 173
 174                         for (Category cat: Category.values()) {
 175                                 if (path.equals('/' + cat.getId())) {
 176                                         writeArticles(cat, resp);
 177                                         return ;
 178                                 }
 179                         }
 180
 181                         resp.getWriter().write("Not found " + req.getPathInfo());
 182                         resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
 183                 } catch (IOException e) {
 184                         LOG.log(Level.SEVERE, "doGet failure", e);
 185                         resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 186                 }
 187         }
 188
 189         @Override
 190         public void init(ServletConfig config) throws ServletException {
 191                 LOG.info("Pnews servlet init " + config.getServletContext().getContextPath());
 192
 193         }
 194 }