|
Oracle® Application Server Syndication Services Developer’s and Administrator’s Guide
10g (9.0.4) Part No. B10667-01 |
|
|
Oracle® Application Server Syndication Services Developer’s and Administrator’s Guide
10g (9.0.4) Part No. B10667-01 |
|
This appendix provides a listing of the RSSCPAdaptor.java program in Section D.1.
A listing of the RSSCPAdaptor.java program follows:
import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;
import org.w3c.dom.*;
import javax.xml.parsers.*;
import oracle.xml.parser.v2.*;
import oracle.syndicate.message.pkg.*;
import oracle.syndicate.server.cp.*;
import oracle.syndicate.server.cp.message.*;
import oracle.syndicate.server.cp.impl.exmsgs.*;
import oracle.syndicate.util.date.*;
// For testing only.
import oracle.syndicate.util.io.*;
import oracle.syndicate.server.cp.impl.message.*;
/**
* Content provider adaptor (content connector) creates a
* CPOffer for each channel defined in a given RSS feed. CPOffers will be
* shown to Syndication Services administrators as resources, for which they can create offers.
* RSS (Really Simple Syndication) is a mechanism for enabling
* lightweight syndication of content.
* More details on RSS can be found at: http://backend.userland.com/rss.
* The adaptor exposes only one property:
* the url of the RSS feed for which the offer has to be created.
* Custom exception messages can be supplied by subclassing the CPException
* class.
* The adaptor code can be compiled as follows:
* javac -d demo/cp/rss/classes -classpath lib/syndserver.jar:../../xdk/lib/xmlparserv2.jar demo/cp/rss/src/RSSCPAdaptor.java
* Standalone unit tests can be run by:
* java -Dhttp.proxyHost=www-proxy.us.oracle.com -Dhttp.proxyPort=80 -classpath lib/syndserver.jar:../../xdk/lib/xmlparserv2.jar:lib/redist/jazn/jazn.jar:demo/cp/rss/classes/ RSSCPAdaptor http://static.userland.com/gems/backend/rssTwoExample2.xml "Scripting News" *
* To install:
* java -DORACLE_HOME=$OH -jar lib/syndserver.jar -installConnector -name "RSS Content Connector" -description "Allows to create offers based on RSS feeds" -className RSSCPAdaptor *
* @version $Header: RSSCPAdaptor.java 03-apr-2003.13:23:05 mcarrer Exp $
* @author mcarrer
* @since release specific (what release of product did this appear in)
*/
public class RSSCPAdaptor
implements CPAdaptor, OSSExceptionConstants
{
private static final String LAST_BUILD_DATE_FORMAT = "EEE, dd MMM yyyy H:mm:ss z";
private String _rssurl;
private CPContext _cpctx;
public RSSCPAdaptor()
{}
/**
* Returns the URL of the RSS feed.
*/
public String getRSSURL()
{
return _rssurl;
}
/**
* Sets the URL of the RSS feed.
*/
public void setRSSURL(String rssurl)
{
_rssurl = rssurl;
}
/**
* Receives and stores the CPContext from which
* you can access the CPMessageFactory object.
*/
public void init(CPContext cpctx)
throws CPException
{
_cpctx = cpctx;
}
public boolean ping()
throws CPException
{
// TODO
return true;
}
/**
* Returns only one offer corresponding to the RSS content feed.
*/
public Iterator buildCatalog()
throws CPException
{
Document docrss = parseRSS();
Element elrss = docrss.getDocumentElement();
NodeList nlchs = elrss.getElementsByTagName("channel");
// Loop over the channels defined in this RSS
// and for each one, create an offer.
CPMessageFactory cpmf = _cpctx.getCPMessageFactory();
ArrayList alOffs = new ArrayList();
for (int i=0; i<nlchs.getLength(); i++) {
// For each channel, you will create
// a CPOffer. CPOffers are shown to
// Syndication administrators as content
// provider resources from which you can build offers.
Element elCh = (Element) nlchs.item(i);
CPOffer cpoff = cpmf.createCPOffer();
// Each offer must have a unique ID for its content provider.
// Set the mandatory ID attribute and any other
// optional attributes.
String title = getChildElementValue(elCh, "title");
if ((title == null) || (title.trim().length() == 0)) {
title = "unknown";
}
// Set the offer properties.
cpoff.setCPOfferID(title);
cpoff.setName(title);
cpoff.setDescription(getChildElementValue(elCh, "description"));
cpoff.setRightsHolder(getChildElementValue(elCh, "copyright"));
cpoff.setProductName("OracleAS Syndication Services RSS Feed Import");
cpoff.setAtomicUse(false);
cpoff.setEditable(true);
cpoff.setShowCredit(false);
cpoff.setUsageRequired(false);
alOffs.add(cpoff);
}
return alOffs.iterator(); }
public CPPackage buildPackage(CPPackageRequest req,
CPRequestContext ctx)
throws CPException
{
// Parse the RSS document.
Document docrss = parseRSS();
Element elrss = docrss.getDocumentElement();
Element elCh = getChannelElement(elrss, req.getOfferID());
// Create a new content package and initialize
// its properties by using RSS feed values.
CPMessageFactory cpmf = _cpctx.getCPMessageFactory();
CPPackage pkg = cpmf.createCPPackage();
// Check if the RSS feed has been modified since the
// the last content package request.
String oldState = req.getState();
String newState = getChildElementValue(elCh, "lastBuildDate");
Date dNewState = getDate(newState);
Date dOldState = null;
if (!oldState.equals(INITIAL_STATE)) {
dOldState = getDate(oldState);
if ((dOldState != null) &&
(dNewState != null) &&
dOldState.equals(dNewState)) {
// The RSS feed has not been updated
// since the last visit. Throw an exception
// notifying that the content package sequence is
// up-to-date and no update needs to be reported.
throw new CPException(CPExceptionConstants.CP_PACKAGE_UP_TO_DATE);
}
// This is an incremental update over
// the previous update that was sent.
// Set the full update flag accordingly.
pkg.setFullUpdate(false);
}
else {
// This is a request for a full new update.
// Set the full update flag accordingly.
pkg.setFullUpdate(true);
}
pkg.setOldState(oldState);
pkg.setNewState(newState);
// Scan through the RSS items, building
// corresponding CPItem objects.
NodeList nlItems = elCh.getElementsByTagName("item");
for (int i=0; i<nlItems.getLength(); i++) {
Element elItem = (Element) nlItems.item(i);
CPItem cpi = cpmf.createCPItem();
// Sets item file name and content type.
// Each RSS news item will have a dummy file name
// and an XML code excerpt for the associated news.
String itemFilename = "item"+i+".xml";
cpi.setContentFilename(itemFilename);
cpi.setContentType("text/xml");
// Sets the item ID.
String guid = getChildElementValue(elItem, "guid");
if (guid != null) {
cpi.setID(guid);
}
// Sets the item name.
String title = getChildElementValue(elItem, "title");
if (title != null) {
cpi.setName(title);
}
else {
// Item name is mandatory,
// so you need to set it
// to a value.
cpi.setName(itemFilename);
}
// Sets the item activation date, if any.
String pubDate = getChildElementValue(elItem, "pubDate");
if (pubDate != null) {
Date dPubDate = getDate(pubDate);
cpi.setActivation( new ISODateTime(dPubDate));
}
// Set the item content to the RSS item XML element.
try {
StringWriter sw = new StringWriter();
((XMLElement) elItem).print( new PrintWriter(sw));
ContentAccessor ca = cpmf.createContentAccessor(sw.toString());
cpi.setContent(ca);
}
catch(Exception e) {
throw new CPException(CPExceptionConstants.CP_GENERIC_ERROR, e, e);
}
// Add the item to the content package.
pkg.addPackageItem(cpi);
}
return pkg;
}
public void closePackage(CPRequestContext ctx)
throws CPException
{
}
private Document parseRSS()
throws CPException
{
Document doc = null;
InputStream is = null;
try {
URL url = new URL(_rssurl);
URLConnection urlc = url.openConnection();
is = urlc.getInputStream();
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
javax.xml.parsers.DocumentBuilder db = dbf.newDocumentBuilder();
doc = db.parse(is);
}
catch (Exception e) {
throw new CPException(CPExceptionConstants.CP_GENERIC_ERROR, e, e);
}
finally {
if (is != null) {
try { is.close(); }
catch (Exception e) {
throw new CPException(CPExceptionConstants.CP_GENERIC_ERROR, e, e);
}
}
}
return doc;
}
private String getChildElementValue(Element el,
String tagName)
throws CPException
{
String value = null;
try {
NodeList nl = el.getElementsByTagName(tagName);
if (nl.getLength() > 0) {
Element elChild = (Element) nl.item(0);
NodeList nl1 = elChild.getChildNodes();
for(int i=0; i<nl1.getLength(); i++) {
Node nChild = nl1.item(i);
int iNodeType = nChild.getNodeType();
if (iNodeType == Node.TEXT_NODE) {
value = nChild.getNodeValue();
break;
}
}
}
}
catch (Exception e) {
throw new CPException(CPExceptionConstants.CP_GENERIC_ERROR, e, e);
}
return value;
}
private Element getChannelElement(Element el,
String chName)
throws CPException
{
Element elch = null;
try {
NodeList nl = el.getElementsByTagName("channel");
for (int i=0; i<nl.getLength(); i++) {
Element elTemp = (Element) nl.item(i);
String chTitle = getChildElementValue(elTemp, "title");
if (chTitle.equals(chName)) {
elch = el;
break;
}
}
}
catch (Exception e) {
throw new CPException(CPExceptionConstants.CP_GENERIC_ERROR, e, e);
}
return elch;
}
private Date getDate(String sd)
throws CPException
{
Date d = null;
try {
if ((sd != null) && (sd.trim().length() != 0)) {
SimpleDateFormat sdf = new SimpleDateFormat(LAST_BUILD_DATE_FORMAT);
d = sdf.parse(sd);
}
}
catch (Exception e) {
throw new CPException(CPExceptionConstants.CP_GENERIC_ERROR, e, e);
}
return d; }
public static void main(String argv[]) throws Exception
{
String rssurl = argv[0];
String offid = argv[1];
RSSCPAdaptor rsscp = new RSSCPAdaptor();
rsscp.init( new oracle.syndicate.server.cp.impl.CPContextImpl());
rsscp.setRSSURL(rssurl);
Iterator itOffs = rsscp.buildCatalog();
while (itOffs.hasNext()) {
CPOffer cpoff = (CPOffer) itOffs.next();
System.out.println("id: "+cpoff.getCPOfferID());
System.out.println("name: "+cpoff.getName());
System.out.println("desc: "+cpoff.getDescription());
System.out.println("rh: "+cpoff.getRightsHolder());
System.out.println("pn: "+cpoff.getProductName());
}
CPPackage pkg = rsscp.buildPackage( new CPPackageRequestImpl(null, null,
offid, null,
null),
null);
Iterator itItems = pkg.getPackageItems();
while (itItems.hasNext()) {
CPItem cpi = (CPItem) itItems.next();
System.out.println("id: "+cpi.getID());
System.out.println("title: "+cpi.getName());
System.out.println("actv: "+cpi.getActivation());
ContentAccessor ca = cpi.getContent();
InputStream cais = ca.openStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
IOUtils.pipe(cais, baos);
System.out.println(baos.toString());
System.out.println("");
}
}
}
|
 Copyright © 2001, 2003 Oracle Corporation All rights reserved |
|