From 1565d0be33cb4d83ee6fa63081bf09ae0a68693d Mon Sep 17 00:00:00 2001
From: "David A. Madore" <david+git@madore.org>
Date: Wed, 31 Aug 2011 17:23:45 +0200
Subject: RSS feed generator.
---
org/madore/damlengine/DamlEngine.java | 4 +
.../damlengine/WeblogDatabaseConnection.java | 1 +
org/madore/damlengine/WeblogRSS.java | 152 +++++++++++++++++++++
3 files changed, 157 insertions(+)
create mode 100644 org/madore/damlengine/WeblogRSS.java
diff --git a/org/madore/damlengine/DamlEngine.java b/org/madore/damlengine/DamlEngine.java
index 070cbab..e54ee86 100644
--- a/org/madore/damlengine/DamlEngine.java
+++ b/org/madore/damlengine/DamlEngine.java
@@ -19,6 +19,10 @@ public final class DamlEngine {
public static final String XML_NS = XMLConstants.XML_NS_URI;
public static final String XHTML_NS = "http://www.w3.org/1999/xhtml";
public static final String DAML_NS = "http://www.madore.org/~david/NS/daml/";
+ public static final String RDF_NS = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
+ public static final String RSS10_NS = "http://purl.org/rss/1.0/";
+ public static final String DUBLINCORE_NS = "http://purl.org/dc/elements/1.1/";
+ public static final String SYNDICATION_NS = "http://purl.org/rss/1.0/modules/syndication/";
public static final class DamlNSMapping implements NamespaceContext {
// This is used for XPath resolution (_not_ for parsing the document).
diff --git a/org/madore/damlengine/WeblogDatabaseConnection.java b/org/madore/damlengine/WeblogDatabaseConnection.java
index a1dfc1f..c88f5a8 100644
--- a/org/madore/damlengine/WeblogDatabaseConnection.java
+++ b/org/madore/damlengine/WeblogDatabaseConnection.java
@@ -23,6 +23,7 @@ public final class WeblogDatabaseConnection {
dbProps.setProperty("ssl", "true");
dbProps.setProperty("sslfactory", "org.postgresql.ssl.NonValidatingFactory");
conn = (new Driver()).connect(dbUrl, dbProps);
+ conn.createStatement().execute("SET TIME ZONE 0");
}
return conn;
}
diff --git a/org/madore/damlengine/WeblogRSS.java b/org/madore/damlengine/WeblogRSS.java
new file mode 100644
index 0000000..c08991c
--- /dev/null
+++ b/org/madore/damlengine/WeblogRSS.java
@@ -0,0 +1,152 @@
+package org.madore.damlengine;
+
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import javax.xml.parsers.DocumentBuilder;
+import org.w3c.dom.*;
+import org.w3c.dom.ls.DOMImplementationLS;
+import org.w3c.dom.ls.LSParser;
+import org.w3c.dom.ls.LSSerializer;
+import org.w3c.dom.ls.LSInput;
+import org.w3c.dom.ls.LSOutput;
+
+public final class WeblogRSS {
+
+ private WeblogRSS() { // Forbid instantiation
+ throw new AssertionError("WeblogRSS cannot be instantiated");
+ }
+
+ public static void main(String[] args)
+ throws Exception {
+
+ final Connection conn = WeblogDatabaseConnection.getConnection();
+
+ final PreparedStatement selSt
+ = conn.prepareStatement("SELECT id , edate , to_char(cdate,'YYYY-MM-DD\"T\"HH24:MI:SS\"Z\"') , lang , title , content FROM entries ORDER BY id DESC LIMIT 15");
+
+ final ResultSet selRes = selSt.executeQuery();
+
+ final DocumentBuilder db = DamlEngine.GetDocumentBuilder.db;
+
+ final DOMImplementationLS domi
+ = (DOMImplementationLS)(db.getDOMImplementation());
+ LSSerializer ser = domi.createLSSerializer();
+ ser.getDomConfig().setParameter("xml-declaration", true);
+ LSParser par = domi.createLSParser(DOMImplementationLS.MODE_SYNCHRONOUS, null);
+
+ final LSOutput out = domi.createLSOutput();
+ out.setByteStream(System.out);
+ out.setEncoding("UTF-8");
+
+ Document rssDoc = db.newDocument();
+ Element rssRoot = rssDoc.createElementNS(DamlEngine.RDF_NS, "rdf:RDF");
+ rssDoc.appendChild(rssRoot);
+ // rssDoc.appendChild(rssDoc.createTextNode("\n"));
+
+ rssRoot.setAttributeNS(DamlEngine.XMLNS_NS, "xmlns:rdf", DamlEngine.RDF_NS);
+ rssRoot.setAttributeNS(DamlEngine.XMLNS_NS, "xmlns", DamlEngine.RSS10_NS);
+ rssRoot.setAttributeNS(DamlEngine.XMLNS_NS, "xmlns:dc", DamlEngine.DUBLINCORE_NS);
+ rssRoot.setAttributeNS(DamlEngine.XMLNS_NS, "xmlns:sy", DamlEngine.SYNDICATION_NS);
+ rssRoot.setAttributeNS(DamlEngine.XML_NS, "xml:lang", "en");
+ rssRoot.appendChild(rssDoc.createTextNode("\n"));
+
+ Element channel = rssDoc.createElementNS(DamlEngine.RSS10_NS, "channel");
+ rssRoot.appendChild(channel);
+ rssRoot.appendChild(rssDoc.createTextNode("\n"));
+ channel.setAttributeNS(DamlEngine.RDF_NS, "rdf:about", "http://www.madore.org/~david/weblog/");
+ channel.appendChild(rssDoc.createTextNode("\n"));
+
+ Element chanTitle = rssDoc.createElementNS(DamlEngine.RSS10_NS, "title");
+ channel.appendChild(chanTitle);
+ channel.appendChild(rssDoc.createTextNode("\n"));
+ chanTitle.appendChild(rssDoc.createTextNode("David Madore's WebLog"));
+ Element syUpdatePeriod = rssDoc.createElementNS(DamlEngine.SYNDICATION_NS, "sy:updatePeriod");
+ channel.appendChild(syUpdatePeriod);
+ channel.appendChild(rssDoc.createTextNode("\n"));
+ syUpdatePeriod.appendChild(rssDoc.createTextNode("hourly"));
+ Element syUpdateFrequency = rssDoc.createElementNS(DamlEngine.SYNDICATION_NS, "sy:updateFrequency");
+ channel.appendChild(syUpdateFrequency);
+ channel.appendChild(rssDoc.createTextNode("\n"));
+ syUpdateFrequency.appendChild(rssDoc.createTextNode("3"));
+ Element syUpdateBase = rssDoc.createElementNS(DamlEngine.SYNDICATION_NS, "sy:updateBase");
+ channel.appendChild(syUpdateBase);
+ channel.appendChild(rssDoc.createTextNode("\n"));
+ syUpdateBase.appendChild(rssDoc.createTextNode("2003-05-01T10:00:00Z"));
+ Element chanItems = rssDoc.createElementNS(DamlEngine.RSS10_NS, "items");
+ channel.appendChild(chanItems);
+ channel.appendChild(rssDoc.createTextNode("\n"));
+ chanItems.appendChild(rssDoc.createTextNode("\n"));
+ Element itemsSeq = rssDoc.createElementNS(DamlEngine.RDF_NS, "rdf:Seq");
+ chanItems.appendChild(itemsSeq);
+ chanItems.appendChild(rssDoc.createTextNode("\n"));
+ itemsSeq.appendChild(rssDoc.createTextNode("\n"));
+
+ while ( selRes.next() ) {
+ int id = selRes.getInt(1);
+ String date = selRes.getString(2);
+ String cdate = selRes.getString(3);
+ String lang = selRes.getString(4);
+ String title = selRes.getString(5);
+ String contentXml = selRes.getString(6);
+ Matcher matcher = Pattern.compile("^(\\d{4})-(\\d{2})-(\\d{2})$").matcher(date);
+ if ( ! matcher.matches() )
+ throw new IllegalArgumentException("entry "+id+" has badly formed date");
+ String yearStr = matcher.group(1);
+ String monthStr = matcher.group(2);
+ // String dayStr = matcher.group(3);
+ String numberStr = String.format("%04d",id);
+ String aboutUri = "http://www.madore.org/~david/weblog/"
+ + "#d." + date + "." + numberStr;
+ String linkUri = "http://www.madore.org/~david/weblog/"
+ + yearStr + "-" + monthStr + ".html"
+ + "#d." + date + "." + numberStr;
+ Element li = rssDoc.createElementNS(DamlEngine.RDF_NS, "rdf:li");
+ itemsSeq.appendChild(li);
+ itemsSeq.appendChild(rssDoc.createTextNode("\n"));
+ li.setAttributeNS(DamlEngine.RDF_NS, "rdf:resource",
+ aboutUri);
+ Element item = rssDoc.createElementNS(DamlEngine.RSS10_NS, "item");
+ rssRoot.appendChild(item);
+ rssRoot.appendChild(rssDoc.createTextNode("\n"));
+ item.setAttributeNS(DamlEngine.RDF_NS, "rdf:about",
+ aboutUri);
+ item.setAttributeNS(DamlEngine.XML_NS, "xml:lang", lang);
+ item.appendChild(rssDoc.createTextNode("\n"));
+ Element itemTitle = rssDoc.createElementNS(DamlEngine.RSS10_NS, "title");
+ item.appendChild(itemTitle);
+ item.appendChild(rssDoc.createTextNode("\n"));
+ itemTitle.appendChild(rssDoc.createTextNode(title));
+ Element itemLink = rssDoc.createElementNS(DamlEngine.RSS10_NS, "link");
+ item.appendChild(itemLink);
+ item.appendChild(rssDoc.createTextNode("\n"));
+ itemLink.appendChild(rssDoc.createTextNode(linkUri));
+ Element itemDate = rssDoc.createElementNS(DamlEngine.DUBLINCORE_NS, "dc:date");
+ item.appendChild(itemDate);
+ item.appendChild(rssDoc.createTextNode("\n"));
+ itemDate.appendChild(rssDoc.createTextNode(cdate));
+ LSInput input = domi.createLSInput();
+ input.setStringData(contentXml);
+ Document temp = par.parse(input);
+ String contentStr = temp.getDocumentElement().getTextContent();
+ int bound;
+ try {
+ bound = Character.offsetByCodePoints(contentStr, 0, 160);
+ } catch (IndexOutOfBoundsException e) {
+ bound = contentStr.length();
+ }
+ String descrStr = contentStr.substring(0, bound).replace("\n"," ");
+ Element itemDescr = rssDoc.createElementNS(DamlEngine.RSS10_NS, "description");
+ item.appendChild(itemDescr);
+ item.appendChild(rssDoc.createTextNode("\n"));
+ itemDescr.appendChild(rssDoc.createTextNode(descrStr));
+ }
+
+ ser.write(rssDoc, out);
+ out.getByteStream().write("\n".getBytes("UTF-8"));
+
+ }
+
+}
--
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