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 ArticleProvider provider;
  31         private Config config;
  32
  33         private static String getQueryParameter(HttpServletRequest rq, String key)
  34                         throws UnsupportedEncodingException {
  35                 final String METHOD_NAME="getQueryParameter";
  36                 String[] params;
  37                 int idx;
  38                 String q;
  39
  40
  41                 LOG.entering(CLASS_NAME, METHOD_NAME, new Object[] { rq, key} );
  42
  43                 q = rq.getQueryString();
  44
  45                 if (q == null)
  46                         return null;
  47
  48                 params = q.split("&");
  49
  50                 for (String p: params) {
  51                         idx = p.indexOf('=');
  52
  53                         if (idx > 1 && p.substring(0, idx).equals(key))
  54                                 return URLDecoder.decode(p.substring(idx + 1), "UTF-8");
  55                 }
  56
  57                 return null;
  58         }
  59
  60         private static void redirect(HttpServletRequest rq, HttpServletResponse rp) {
  61                 String redirectURL;
  62                 Article a;
  63
  64                 LOG.entering(Pnews.class.getName(), "redirect", new Object[] { rq, rp });
  65
  66                 try {
  67                         redirectURL = getQueryParameter(rq, "url");
  68
  69                         LOG.info("Request redirection to " + redirectURL);
  70
  71                         if (redirectURL != null) {
  72                                 a = ArticleStore.singleton.get(redirectURL);
  73                                 if (a != null)
  74                                         a.readCount.incrementAndGet();
  75                                 else
  76                                         LOG.severe("Cannot find the article " + redirectURL);
  77
  78                                 rp.setHeader("Location", redirectURL);
  79                                 rp.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
  80                         } else {
  81                                 LOG.severe("No redirection URL");
  82                                 rp.setStatus(HttpServletResponse.SC_NOT_FOUND);
  83                         }
  84
  85                 } catch (UnsupportedEncodingException e) {
  86                         e.printStackTrace();
  87                         LOG.log(Level.SEVERE, "redirect failure", e);
  88                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
  89                 }
  90
  91                 LOG.exiting(Pnews.class.getName(), "redirect");
  92         }
  93
  94         private void writeStats(HttpServletResponse rp) throws IOException {
  95                 rp.setContentType("application/json;charset=utf-8");
  96                 rp.setCharacterEncoding("utf-8");
  97
  98                 rp.getWriter().write(JSON.getStats(config.getCategories()));
  99         }
 100
 101
 102         private void writeArticles(Category cat, HttpServletResponse rp) {
 103                 String html;
 104                 List<Article> articles;
 105
 106                 try {
 107                         articles = provider.getArticles(cat);
 108                         if (articles != null) {
 109                                 html = HTML.toHTML(articles, cat, config.getCategories());
 110                                 rp.setContentType("text/html;charset=utf-8");
 111                                 rp.getWriter().write(html);
 112                                 rp.setCharacterEncoding("utf-8");
 113                         } else {
 114                                 LOG.severe("writeArticles cannot retrieve any articles");
 115                                 html = HTML.toHTML(new ArrayList<Article>(), cat, config.getCategories());
 116                                 rp.setContentType("text/html");
 117                                 rp.getWriter().write(html);
 118                         }
 119                 } catch (IOException | IllegalArgumentException | FeedException e) {
 120                         LOG.log(Level.SEVERE, "writeArticles failure", e);
 121                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 122                 }
 123         }
 124
 125         private void copy(InputStream in, Writer writer) throws IOException {
 126                 Reader r;
 127                 char[] buf;
 128                 int n;
 129
 130                 buf = new char[1024];
 131                 r = new InputStreamReader(in);
 132                 while ( (n = r.read(buf, 0, buf.length)) != -1)
 133                         writer.write(buf, 0, n);
 134         }
 135
 136         @Override
 137         protected void doGet(HttpServletRequest req, HttpServletResponse resp) {
 138                 final String METHOD_NAME = "doGet";
 139                 String path;
 140                 InputStream in;
 141
 142                 RequesterLog.singleton.writeRequest(req);
 143
 144                 LOG.info("doGet " + req.getRemoteAddr().toString() + " " + req.getRequestURI() + " " + req.getQueryString());
 145
 146                 LOG.info(METHOD_NAME + " queryString=" + req.getQueryString());
 147
 148                 path = req.getPathInfo();
 149
 150                 if (path.equals("/redirect")) {
 151                         redirect(req, resp);
 152                         return ;
 153                 }
 154
 155                 if (path.equals("/style.css")) {
 156                         try {
 157                                 in = HTML.class.getClassLoader().getResourceAsStream("style.css");
 158                                 copy(in, resp.getWriter());
 159                                 resp.setContentType("text/css");
 160
 161                                 return ;
 162                         } catch (IOException e) {
 163                                 LOG.log(Level.SEVERE, "doGet failure", e);
 164                                 resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 165
 166                                 return ;
 167                         }
 168                 }
 169
 170                 if (path.equals("/")) {
 171                         writeArticles(config.getDefaultCategory(), resp);
 172                         return ;
 173                 }
 174
 175                 try {
 176
 177                         if (path.equals("/stats")) {
 178                                 writeStats(resp);
 179                                 return ;
 180                         }
 181
 182                         for (Category cat: config.getCategories()) {
 183                                 if (path.equals(cat.getURL())) {
 184                                         writeArticles(cat, resp);
 185                                         return ;
 186                                 }
 187                         }
 188
 189                         resp.getWriter().write("Not found " + req.getPathInfo());
 190                         resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
 191                 } catch (IOException e) {
 192                         LOG.log(Level.SEVERE, "doGet failure", e);
 193                         resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 194                 }
 195         }
 196
 197         @Override
 198         public void init(ServletConfig cfg) throws ServletException {
 199                 LOG.info("Pnews servlet init " + cfg.getServletContext().getContextPath());
 200
 201                 config = new Config();
 202                 try {
 203                         config.loadConfig();
 204                 } catch (UnsupportedEncodingException e) {
 205                         throw new ServletException(e);
 206                 }
 207
 208                 provider = new ArticleProvider(config);
 209         }
 210 }