package pnews.servlet;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.UnsupportedEncodingException;
+import java.io.Writer;
+import java.net.URLDecoder;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import com.rometools.rome.io.FeedException;
+
+import pnews.Article;
+import pnews.Category;
+import pnews.HTML;
public class Pnews extends HttpServlet {
+ private static final Logger LOG = Logger.getLogger(Pnews.class.getName());
+ private static final long serialVersionUID = 1L;
+ private static final ArticleProvider provider = ArticleProvider.singleton;
+
+ private static String getQueryParameter(HttpServletRequest rq, String key)
+ throws UnsupportedEncodingException {
+ String[] params;
+ int idx;
+ String q;
+
+ q = rq.getQueryString();
+
+ if (q == null)
+ return null;
+
+ params = URLDecoder.decode(q, "UTF-8").split("&");
+
+ for (String p: params) {
+ idx = p.indexOf('=');
+
+ if (idx > 1 && p.substring(0, idx).equals(key))
+ return p.substring(idx + 1);
+ }
+
+ return null;
+ }
+
+ private static void redirect(HttpServletRequest rq, HttpServletResponse rp) {
+ String redirectURL;
+
+ LOG.entering(Pnews.class.getName(), "redirect");
+
+ try {
+ redirectURL = getQueryParameter(rq, "url");
+
+ LOG.info("Request redirection to " + redirectURL);
+
+ if (redirectURL != null) {
+ rp.setHeader("Location", redirectURL);
+ rp.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
+ } else {
+ LOG.severe("No redirection URL");
+ rp.setStatus(HttpServletResponse.SC_NOT_FOUND);
+ }
+
+ } catch (UnsupportedEncodingException e) {
+ e.printStackTrace();
+ LOG.log(Level.SEVERE, "redirect failure", e);
+ rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+ }
+
+ LOG.exiting(Pnews.class.getName(), "redirect");
+ }
+
+ private void writeArticles(Category cat, HttpServletResponse rp) {
+ String html;
+ List<Article> articles;
+
+ try {
+ articles = provider.getArticles(cat);
+ if (articles != null) {
+ html = HTML.toHTML(articles, cat);
+ rp.setContentType("text/html");
+ rp.getWriter().write(html);
+ } else {
+ LOG.severe("writeArticles cannot retrieve any articles");
+ html = HTML.toHTML(new ArrayList<Article>(), cat);
+ rp.setContentType("text/html");
+ rp.getWriter().write(html);
+ }
+ } catch (IOException | IllegalArgumentException | FeedException e) {
+ LOG.log(Level.SEVERE, "writeArticles failure", e);
+ rp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+ }
+ }
+
+ private void copy(InputStream in, Writer writer) throws IOException {
+ Reader r;
+ char[] buf;
+ int n;
+
+ buf = new char[1024];
+ r = new InputStreamReader(in);
+ while ( (n = r.read(buf, 0, buf.length)) != -1)
+ writer.write(buf, 0, n);
+ }
+
+ @Override
+ protected void doGet(HttpServletRequest req, HttpServletResponse resp) {
+ String path;
+ InputStream in;
+
+ LOG.info("doGet " + req.getRequestURI());
+ path = req.getPathInfo();
+
+ if (path.equals("/redirect")) {
+ redirect(req, resp);
+ return ;
+ }
+
+ if (path.equals("/style.css")) {
+ try {
+ in = HTML.class.getClassLoader().getResourceAsStream("style.css");
+ copy(in, resp.getWriter());
+ resp.setContentType("text/css");
+
+ return ;
+ } catch (IOException e) {
+ LOG.log(Level.SEVERE, "doGet failure", e);
+ resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+
+ return ;
+ }
+ }
+
+ if (path.equals("/")) {
+ writeArticles(Category.TOP, resp);
+ return ;
+ }
+
+ for (Category cat: Category.values()) {
+ if (path.equals('/' + cat.getId())) {
+ writeArticles(cat, resp);
+ return ;
+ }
+ }
+
+ try {
+ resp.getWriter().write("Not found " + req.getPathInfo());
+ resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
+ } catch (IOException e) {
+ LOG.log(Level.SEVERE, "doGet failure", e);
+ resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+ }
+ }
+
+ @Override
+ public void init(ServletConfig config) throws ServletException {
+ LOG.info("Pnews servlet init " + config.getServletContext().getContextPath());
+
+ }
}