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.Locale;
  13 import java.util.logging.Level;
  14 import java.util.logging.Logger;
  15
  16 import javax.servlet.ServletConfig;
  17 import javax.servlet.ServletException;
  18 import javax.servlet.http.HttpServlet;
  19 import javax.servlet.http.HttpServletRequest;
  20 import javax.servlet.http.HttpServletResponse;
  21
  22 import com.rometools.rome.io.FeedException;
  23
  24 import pnews.Article;
  25 import pnews.Category;
  26 import pnews.HTML;
  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
  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                                 rp.setHeader("Location", redirectURL);
  68                                 rp.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
  69                         } else {
  70                                 LOG.severe("No redirection URL");
  71                                 rp.setStatus(HttpServletResponse.SC_NOT_FOUND);
  72                         }
  73
  74                 } catch (UnsupportedEncodingException e) {
  75                         e.printStackTrace();
  76                         LOG.log(Level.SEVERE, "redirect failure", e);
  77                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
  78                 }
  79
  80                 LOG.exiting(Pnews.class.getName(), "redirect");
  81         }
  82
  83         private void writeArticles(Category cat, HttpServletResponse rp) {
  84                 String html;
  85                 List<Article> articles;
  86
  87                 try {
  88                         articles = provider.getArticles(cat);
  89                         if (articles != null) {
  90                                 html = HTML.toHTML(articles, cat);
  91                                 rp.setContentType("text/html;charset=utf-8");
  92                                 rp.getWriter().write(html);
  93                                 rp.setCharacterEncoding("utf8-8");
  94                         } else {
  95                                 LOG.severe("writeArticles cannot retrieve any articles");
  96                                 html = HTML.toHTML(new ArrayList<Article>(), cat);
  97                                 rp.setContentType("text/html");
  98                                 rp.getWriter().write(html);
  99                         }
 100                 } catch (IOException | IllegalArgumentException | FeedException e) {
 101                         LOG.log(Level.SEVERE, "writeArticles failure", e);
 102                         rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 103                 }
 104         }
 105
 106         private void copy(InputStream in, Writer writer) throws IOException {
 107                 Reader r;
 108                 char[] buf;
 109                 int n;
 110
 111                 buf = new char[1024];
 112                 r = new InputStreamReader(in);
 113                 while ( (n = r.read(buf, 0, buf.length)) != -1)
 114                         writer.write(buf, 0, n);
 115         }
 116
 117         @Override
 118         protected void doGet(HttpServletRequest req, HttpServletResponse resp) {
 119                 String path;
 120                 InputStream in;
 121
 122                 RequesterLog.singleton.writeRequest(req);
 123
 124                 LOG.info("doGet " + req.getRemoteAddr().toString() + " " + req.getRequestURI() + " " + req.getQueryString());
 125
 126                 path = req.getPathInfo();
 127
 128                 if (path.equals("/redirect")) {
 129                         redirect(req, resp);
 130                         return ;
 131                 }
 132
 133                 if (path.equals("/style.css")) {
 134                         try {
 135                                 in = HTML.class.getClassLoader().getResourceAsStream("style.css");
 136                                 copy(in, resp.getWriter());
 137                                 resp.setContentType("text/css");
 138
 139                                 return ;
 140                         } catch (IOException e) {
 141                                 LOG.log(Level.SEVERE, "doGet failure", e);
 142                                 resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 143
 144                                 return ;
 145                         }
 146                 }
 147
 148                 if (path.equals("/")) {
 149                         writeArticles(Category.TOP, resp);
 150                         return ;
 151                 }
 152
 153                 for (Category cat: Category.values()) {
 154                         if (path.equals('/' + cat.getId())) {
 155                                 writeArticles(cat, resp);
 156                                 return ;
 157                         }
 158                 }
 159
 160                 try {
 161                         resp.getWriter().write("Not found " + req.getPathInfo());
 162                         resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
 163                 } catch (IOException e) {
 164                         LOG.log(Level.SEVERE, "doGet failure", e);
 165                         resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
 166                 }
 167         }
 168
 169         @Override
 170         public void init(ServletConfig config) throws ServletException {
 171                 LOG.info("Pnews servlet init " + config.getServletContext().getContextPath());
 172
 173         }
 174 }