/*
* FeedRepresentation.java
*
* Created on March 27, 2007, 11:55 PM
*
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
*/
package org.atomojo.app;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URLDecoder;
import java.sql.SQLException;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
import java.util.UUID;
import java.util.logging.Level;
import org.atomojo.app.client.XMLRepresentationParser;
import org.atomojo.app.db.Entry;
import org.atomojo.app.db.Feed;
import org.atomojo.app.db.Term;
import org.atomojo.app.db.TermInstance;
import org.atomojo.app.db.sparql.QueryContext;
import org.atomojo.app.db.sparql.QueryException;
import org.atomojo.sparql.ParseException;
import org.atomojo.sparql.Parser;
import org.atomojo.sparql.Query;
import org.infoset.xml.Document;
import org.infoset.xml.DocumentLoader;
import org.infoset.xml.Element;
import org.infoset.xml.InfosetFactory;
import org.infoset.xml.ItemConstructor;
import org.infoset.xml.ItemDestination;
import org.infoset.xml.Name;
import org.infoset.xml.XMLException;
import org.infoset.xml.filter.RemoveDocumentFilter;
import org.infoset.xml.sax.SAXDocumentLoader;
import org.infoset.xml.util.WriterItemDestination;
import org.restlet.data.CharacterSet;
import org.restlet.data.MediaType;
import org.restlet.data.Reference;
import org.restlet.data.Status;
import org.restlet.representation.OutputRepresentation;
import org.restlet.representation.Representation;
import org.restlet.representation.StringRepresentation;
import org.restlet.resource.ServerResource;
/**
*
* @author alex
*/
public class TermListResource extends ServerResource {
static final URI CHILD_TERM = URI.create("http://www.atomojo.org/O/relations/child");
static final URI ANCESTOR_TERM = URI.create("http://www.atomojo.org/O/relations/ancestor");
Reference termBase;
Reference resourceBase;
App app;
class TermQuery {
Term dbTerm;
String value;
TermQuery(URI u,String value)
throws SQLException
{
this.value = value;
this.dbTerm = app.getDB().findTerm(u);
}
}
/** Creates a new instance of FeedRepresentation */
public TermListResource(Reference termBase,Reference resourceBase,App app) {
setNegotiated(false);
this.termBase = termBase;
this.resourceBase = resourceBase;
this.app = app;
}
public Representation get() {
return new OutputRepresentation(MediaType.APPLICATION_ATOM_XML) {
public void write(OutputStream os)
throws IOException
{
setCharacterSet(CharacterSet.UTF_8);
try {
generate(new WriterItemDestination(new OutputStreamWriter(os,"UTF-8"),"UTF-8"));
} catch (XMLException ex) {
getContext().getLogger().log(Level.SEVERE,"Cannot serialize metadata feed.",ex);
throw new IOException("Cannot serialize metadata feed: "+ex.getMessage());
}
}
};
}
public void generate(ItemDestination dest)
throws XMLException
{
Date now = new Date();
ItemConstructor constructor = InfosetFactory.getDefaultInfoset().createItemConstructor();
dest.send(constructor.createDocument());
dest.send(constructor.createElement(AtomResource.FEED_NAME));
link(constructor,dest,"self",getRequest().getResourceRef().toString());
text(constructor,dest,AtomResource.TITLE_NAME,"Terms");
text(constructor,dest,AtomResource.ID_NAME,getRequest().getResourceRef().toString());
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(now));
try {
Iterator<Term> terms = app.getDB().getTerms();
while (terms.hasNext()) {
Term t = terms.next();
dest.send(constructor.createElement(AtomResource.ENTRY_NAME));
String termRef = termBase.toString()+t.getURI();
text(constructor,dest,AtomResource.ID_NAME,termRef);
text(constructor,dest,AtomResource.PUBLISHED_NAME,AtomResource.toXSDDate(now));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(now));
text(constructor,dest,AtomResource.TITLE_NAME,"Term "+t.getURI());
term(constructor,dest,Categorization.TERM_TYPE_TERM,null);
term(constructor,dest,t.getURI(),null);
link(constructor,dest,"related",termRef);
dest.send(constructor.createElementEnd(AtomResource.ENTRY_NAME));
}
} catch (Exception ex) {
throw new XMLException("Exception while getting terms.",ex);
}
dest.send(constructor.createElementEnd(AtomResource.FEED_NAME));
dest.send(constructor.createDocumentEnd());
}
public Representation post(Representation entity) {
if (entity==null) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("Missing post body.");
}
MediaType postType = entity.getMediaType();
if (postType.getName().equals("application/sparql-query")) {
return handleSparqlPost(entity);
} else if (!postType.getName().equals(MediaType.APPLICATION_XML.getName())) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("Non-xml media type "+postType.getName());
}
String charset = postType.getParameters().getValues("charset");
if (charset==null) {
charset = "UTF-8";
}
Document doc = null;
DocumentLoader loader = new SAXDocumentLoader();
try {
Reader r = new InputStreamReader(entity.getStream(),charset);
doc = loader.load(r);
r.close();
} catch (IOException ex) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("I/O error while parsing document: "+ex.getMessage());
} catch (XMLException ex) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("XML error while parsing document: "+ex.getMessage());
}
Element top = doc.getDocumentElement();
if (!top.getName().equals(AtomResource.CATEGORIES_NAME)) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("Unexpected document element "+top.getName());
}
URI firstTerm = null;
final Map<URI,TermQuery> termSet = new TreeMap<URI,TermQuery>();
Iterator<Element> categories = top.getElementsByName(AtomResource.CATEGORY_NAME);
try {
while (categories.hasNext()) {
org.atomojo.app.client.Term term = org.atomojo.app.client.Term.derive(categories.next());
URI termURI = term.getURI();
String value = term.getFirstValue();
termSet.put(termURI, new TermQuery(termURI,value));
if (firstTerm==null) {
firstTerm = termURI;
}
}
} catch (SQLException ex) {
getLogger().log(Level.SEVERE,"Database error while getting term.",ex);
getResponse().setStatus(Status.SERVER_ERROR_INTERNAL);
return new StringRepresentation("Database error.");
}
if (firstTerm==null) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("Empty category set.");
}
final URI keyTerm = firstTerm;
getResponse().setStatus(Status.SUCCESS_OK);
return new OutputRepresentation(MediaType.APPLICATION_ATOM) {
public void write(OutputStream os)
throws IOException
{
setCharacterSet(CharacterSet.UTF_8);
try {
generate(new WriterItemDestination(new OutputStreamWriter(os,"UTF-8"),"UTF-8"),keyTerm,termSet);
} catch (XMLException ex) {
getContext().getLogger().log(Level.SEVERE,"Cannot serialize metadata feed.",ex);
throw new IOException("Cannot serialize metadata feed: "+ex.getMessage());
}
}
};
}
public Representation handleSparqlPost(Representation entity) {
MediaType postType = entity.getMediaType();
String charset = postType.getParameters().getValues("charset");
if (charset==null) {
charset = "UTF-8";
}
try {
Reader r = new InputStreamReader(entity.getStream(),charset);
Parser parser = new Parser(getLogger());
Query query = parser.parseQuery(r);
r.close();
getResponse().setStatus(Status.SUCCESS_OK);
final QueryContext context = new QueryContext(getLogger(),app.getDB(),query);
final XMLRepresentationParser xmlParser = new XMLRepresentationParser();
return new OutputRepresentation(MediaType.APPLICATION_ATOM) {
public void write(OutputStream os)
throws IOException
{
final ItemDestination dest = new WriterItemDestination(new OutputStreamWriter(os,"UTF-8"),"UTF-8");
final ItemConstructor constructor = InfosetFactory.getDefaultInfoset().createItemConstructor();
try {
context.execute(new QueryContext.ResultListener() {
DocumentLoader loader = new SAXDocumentLoader();
public void onStart() throws QueryException {
try {
dest.send(constructor.createDocument());
dest.send(constructor.createElement(AtomResource.FEED_NAME));
dest.send(constructor.createCharacters("\n"));
link(constructor,dest,"self",getRequest().getResourceRef().toString());
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.TITLE_NAME,"Term Query");
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.ID_NAME,UUID.randomUUID().toString());
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(new Date()));
} catch (XMLException ex) {
throw new QueryException("Exception during feed start.",ex);
}
}
public void onEnd() throws QueryException {
try {
dest.send(constructor.createCharacters("\n"));
dest.send(constructor.createElementEnd(AtomResource.FEED_NAME));
dest.send(constructor.createDocumentEnd());
} catch (XMLException ex) {
throw new QueryException("Exception during feed end.",ex);
}
}
public void onEntry(Entry entry) throws QueryException {
try {
Feed feed = entry.getFeed();
String feedPath = feed.getPath();
String feedBaseURI = resourceBase.toString()+feedPath;
dest.send(constructor.createCharacters("\n"));
// get the entry representation
Representation rep = app.getStorage().getEntry(feedBaseURI,feedPath,feed.getUUID(),entry.getUUID());
// avoid thread creation because reading an output representation requires a thread
StringWriter sw = new StringWriter();
rep.write(sw);
rep.release();
// TODO: optimize by giving item destination to storage
loader.generate(new StringReader(sw.toString()), new RemoveDocumentFilter(dest));
} catch (Exception ex) {
throw new QueryException("Exception during feed entry generation.",ex);
}
}
public void onFeed(Feed feed) throws QueryException {
try {
org.atomojo.app.client.Feed feedRep = new org.atomojo.app.client.Feed(xmlParser.load(app.getStorage().getFeedHead(feed.getPath(), feed.getUUID())));
dest.send(constructor.createCharacters("\n"));
dest.send(constructor.createElement(AtomResource.ENTRY_NAME));
text(constructor,dest,AtomResource.ID_NAME,feed.getUUID().toString());
text(constructor,dest,AtomResource.PUBLISHED_NAME,AtomResource.toXSDDate(feed.getCreated()));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(feed.getEdited()));
text(constructor,dest,AtomResource.TITLE_NAME,feedRep.getTitle());
String summary = feedRep.getSummary();
text(constructor,dest,AtomResource.SUMMARY_NAME,summary);
term(constructor,dest,Categorization.FEED_TYPE_TERM,null);
Iterator<TermInstance<Feed>> terms = feed.getTerms();
while (terms.hasNext()) {
TermInstance<Feed> fterm = terms.next();
term(constructor,dest,fterm.getTerm().getURI(),fterm.getValue());
}
link(constructor,dest,"related",resourceBase+feed.getPath());
dest.send(constructor.createElementEnd(AtomResource.ENTRY_NAME));
} catch (Exception ex) {
throw new QueryException("Exception during feed entry generation.",ex);
}
}
} );
} catch (QueryException ex) {
getContext().getLogger().log(Level.SEVERE,"Cannot execute query",ex);
throw new IOException("Cannot execute query: "+ex.getMessage());
}
}
};
} catch (ParseException ex) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("Error while parsing query: "+ex.getMessage());
} catch (QueryException ex) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("Error while processing query: "+ex.getMessage());
} catch (IOException ex) {
getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return new StringRepresentation("I/O exception while parsing query.");
}
}
public void generate(ItemDestination dest,URI keyTerm,Map<URI,TermQuery> termSet)
throws XMLException
{
TermQuery key = termSet.remove(keyTerm);
boolean found = key.dbTerm!=null;
for (URI u : termSet.keySet()) {
TermQuery t = termSet.get(u);
if (t.dbTerm==null) {
found = false;
break;
}
}
ItemConstructor constructor = InfosetFactory.getDefaultInfoset().createItemConstructor();
dest.send(constructor.createDocument());
dest.send(constructor.createElement(AtomResource.FEED_NAME));
dest.send(constructor.createCharacters("\n"));
link(constructor,dest,"self",getRequest().getResourceRef().toString());
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.TITLE_NAME,"Term Query");
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.ID_NAME,getRequest().getResourceRef().toString());
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(new Date()));
try {
if (found) {
Iterator<TermInstance<Feed>> feeds = app.getDB().getFeedsByTerm(key.dbTerm,key.value);
while (feeds.hasNext()) {
TermInstance<Feed> termValue = feeds.next();
Feed feed = termValue.getTarget();
boolean ok = true;
for (URI otherTerm : termSet.keySet()) {
TermQuery other = termSet.get(otherTerm);
ok = feed.hasTerm(other.dbTerm, other.value);
if (!ok) {
break;
}
}
if (ok) {
dest.send(constructor.createCharacters("\n"));
dest.send(constructor.createElement(AtomResource.ENTRY_NAME));
text(constructor,dest,AtomResource.ID_NAME,feed.getUUID().toString());
text(constructor,dest,AtomResource.PUBLISHED_NAME,AtomResource.toXSDDate(feed.getCreated()));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(feed.getEdited()));
text(constructor,dest,AtomResource.TITLE_NAME,app.getStorage().getFeedTitle(feed.getPath(),feed.getUUID()));
term(constructor,dest,Categorization.FEED_TYPE_TERM,null);
Iterator<TermInstance<Feed>> terms = feed.getTerms();
while (terms.hasNext()) {
TermInstance<Feed> fterm = terms.next();
term(constructor,dest,fterm.getTerm().getURI(),fterm.getValue());
}
link(constructor,dest,"related",resourceBase+feed.getPath());
dest.send(constructor.createElementEnd(AtomResource.ENTRY_NAME));
}
}
DocumentLoader loader = new SAXDocumentLoader();
Iterator<TermInstance<Entry>> entries = app.getDB().getEntriesByTerm(key.dbTerm,key.value);
while (entries.hasNext()) {
TermInstance<Entry> termValue = entries.next();
Entry entry = termValue.getTarget();
boolean ok = true;
for (URI otherTerm : termSet.keySet()) {
TermQuery other = termSet.get(otherTerm);
ok = entry.hasTerm(other.dbTerm, other.value);
if (!ok) {
break;
}
}
if (ok) {
Feed feed = entry.getFeed();
String feedPath = feed.getPath();
String feedBaseURI = resourceBase.toString()+feedPath;
dest.send(constructor.createCharacters("\n"));
// get the entry representation
Representation rep = app.getStorage().getEntry(feedBaseURI,feedPath,feed.getUUID(),entry.getUUID());
// avoid thread creation because reading an output representation requires a thread
StringWriter sw = new StringWriter();
rep.write(sw);
rep.release();
loader.generate(new StringReader(sw.toString()), new RemoveDocumentFilter(dest));
}
}
}
} catch (Exception ex) {
throw new XMLException("Exception while getting ancestors.",ex);
}
dest.send(constructor.createCharacters("\n"));
dest.send(constructor.createElementEnd(AtomResource.FEED_NAME));
dest.send(constructor.createDocumentEnd());
}
static void text(ItemConstructor constructor,ItemDestination dest,Name name,String text)
throws XMLException
{
dest.send(constructor.createElement(name));
dest.send(constructor.createCharacters(text));
dest.send(constructor.createElementEnd(name));
}
static void term(ItemConstructor constructor,ItemDestination dest,URI term,Object value)
throws XMLException
{
String [] parts = new String[2];
Term.split(term,parts);
try {
Element termE = constructor.createElement(AtomResource.CATEGORY_NAME);
if (!parts[0].equals("http://www.atomojo.org/O/keyword/")) {
termE.setAttributeValue("scheme",parts[0]);
}
termE.setAttributeValue("term",URLDecoder.decode(parts[1],"UTF-8"));
dest.send(termE);
if (value!=null) {
dest.send(constructor.createCharacters(value.toString()));
}
dest.send(constructor.createElementEnd(AtomResource.CATEGORY_NAME));
} catch (UnsupportedEncodingException ex) {
throw new XMLException("Cannot decode term "+parts[1],ex);
}
}
static void link(ItemConstructor constructor,ItemDestination dest,String rel,String href)
throws XMLException
{
Element linkE = constructor.createElement(AtomResource.LINK_NAME);
linkE.setAttributeValue("rel",rel);
linkE.setAttributeValue("href",href);
linkE.setAttributeValue("type","application/atom+xml");
dest.send(linkE);
dest.send(constructor.createElementEnd(AtomResource.LINK_NAME));
}
}