/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cocoon.generation;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.ResourceNotFoundException;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.Constants;
import org.apache.commons.lang.StringUtils;
import org.apache.regexp.RE;
import org.apache.regexp.RESyntaxException;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import java.io.IOException;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URLConnection;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;
/**
* @cocoon.sitemap.component.documentation
* Generates a list of links that are reachable from the src and their status.
*
* @cocoon.sitemap.component.name linkstatus
* @cocoon.sitemap.component.label content
* @cocoon.sitemap.component.logger sitemap.generator.linkstatus
*
* @author Michael Homeijer
* @author Nicola Ken Barozzi (nicolaken@apache.org)
* @author Bernhard Huber (huber@apache.org)
* @version $Id$
*/
public class LinkStatusGenerator extends ServiceableGenerator
implements Configurable {
/** The URI of the namespace of this generator. */
protected static final String URI =
"http://apache.org/cocoon/linkstatus/2.0";
/** The namespace prefix for this namespace. */
protected static final String PREFIX = "linkstatus";
/* Node and attribute names */
protected static final String TOP_NODE_NAME = "linkstatus";
protected static final String LINK_NODE_NAME = "link";
protected static final String HREF_ATTR_NAME = "href";
protected static final String REFERRER_ATTR_NAME = "referrer";
protected static final String CONTENT_ATTR_NAME = "content";
protected static final String STATUS_ATTR_NAME = "status";
protected static final String MESSAGE_ATTR_NAME = "message";
protected AttributesImpl attributes;
/**
* Config element name specifying expected link content-typ.
* <p>
* Its value is <code>link-content-type</code>.
* </p>
*
* @since
*/
public final static String LINK_CONTENT_TYPE_CONFIG = "link-content-type";
/**
* Default value of <code>link-content-type</code> configuration value.
* <p>
* Its value is <code>application/x-cocoon-links</code>.
* </p>
*
* @since
*/
public final String LINK_CONTENT_TYPE_DEFAULT = "application/x-cocoon-links";
/**
* Config element name specifying query-string appendend for requesting links
* of an URL.
* <p>
* Its value is <code>link-view-query</code>.
* </p>
*
* @since
*/
public final static String LINK_VIEW_QUERY_CONFIG = "link-view-query";
/**
* Default value of <code>link-view-query</code> configuration value.
* <p>
* Its value is <code>?cocoon-view=links</code>.
* </p>
*
* @since
*/
public final static String LINK_VIEW_QUERY_DEFAULT = "cocoon-view=links";
/**
* Config element name specifying excluding regular expression pattern.
* <p>
* Its value is <code>exclude</code>.
* </p>
*
* @since
*/
public final static String EXCLUDE_CONFIG = "exclude";
/**
* Config element name specifying including regular expression pattern.
* <p>
* Its value is <code>include</code>.
* </p>
*
* @since
*/
public final static String INCLUDE_CONFIG = "include";
/**
* Config element name specifying http header value for user-Agent.
* <p>
* Its value is <code>user-agent</code>.
* </p>
*
* @since
*/
public final static String USER_AGENT_CONFIG = "user-agent";
/**
* Default value of <code>user-agent</code> configuration value.
*
* @see org.apache.cocoon.Constants#COMPLETE_NAME
* @since
*/
public final static String USER_AGENT_DEFAULT = Constants.COMPLETE_NAME;
/**
* Config element name specifying http header value for accept.
* <p>
* Its value is <code>accept</code>.
* </p>
*
* @since
*/
public final static String ACCEPT_CONFIG = "accept";
/**
* Default value of <code>accept</code> configuration value.
* <p>
* Its value is <code>* / *</code>
* </p>
*
* @since
*/
public final static String ACCEPT_DEFAULT = "*/*";
private String linkViewQuery = LINK_VIEW_QUERY_DEFAULT;
private String linkContentType = LINK_CONTENT_TYPE_DEFAULT;
private HashSet excludeCrawlingURL;
private HashSet includeCrawlingURL;
// FIXME - The following two are never read, can we delete them?
//private String userAgent = USER_AGENT_DEFAULT;
//private String accept = ACCEPT_DEFAULT;
private HashSet crawled;
private HashSet linksToProcess;
/**
* Stores links to process and the referrer links
*/
private static class Link {
private URL url;
private String referrer;
public Link(URL url, String referrer) {
this.url = url;
this.referrer = referrer;
}
public URL getURL() {
return url;
}
public String getReferrer() {
return referrer;
}
public boolean equals(Link l) {
return url.equals(l.getURL());
}
}
/**
* Configure the crawler component.
* <p>
* Configure can specify which URI to include, and which URI to exclude
* from crawling. You specify the patterns as regular expressions.
* </p>
* <p>
* Morover you can configure
* the required content-type of crawling request, and the
* query-string appended to each crawling request.
* </p>
* <pre><tt>
* <include>.*\.html?</include> or <include>.*\.html?, .*\.xsp</include>
* <exclude>.*\.gif</exclude> or <exclude>.*\.gif, .*\.jpe?g</exclude>
* <link-content-type> application/x-cocoon-links </link-content-type>
* <link-view-query> ?cocoon-view=links </link-view-query>
* <user-agent> Cocoon </user-agent>
* <accept> text/xml </accept>
* </tt></pre>
*
* @param configuration XML configuration of this avalon component.
* @exception ConfigurationException is throwing if configuration is invalid.
* @since
*/
public void configure(Configuration configuration)
throws ConfigurationException {
Configuration[] children;
children = configuration.getChildren(INCLUDE_CONFIG);
if (children.length > 0) {
includeCrawlingURL = new HashSet();
for (int i = 0; i < children.length; i++) {
String pattern = children[i].getValue();
try {
String params[] = StringUtils.split(pattern, ", ");
for (int index = 0; index < params.length; index++) {
String tokenized_pattern = params[index];
this.includeCrawlingURL.add(new RE(tokenized_pattern));
}
} catch (RESyntaxException rese) {
getLogger().error("Cannot create including regular-expression for " +
pattern, rese);
}
}
}
children = configuration.getChildren(EXCLUDE_CONFIG);
if (children.length > 0) {
excludeCrawlingURL = new HashSet();
for (int i = 0; i < children.length; i++) {
String pattern = children[i].getValue();
try {
String params[] = StringUtils.split(pattern, ", ");
for (int index = 0; index < params.length; index++) {
String tokenized_pattern = params[index];
this.excludeCrawlingURL.add(new RE(tokenized_pattern));
}
} catch (RESyntaxException rese) {
getLogger().error("Cannot create excluding regular-expression for " +
pattern, rese);
}
}
} else {
excludeCrawlingURL = new HashSet();
setDefaultExcludeFromCrawling();
}
Configuration child;
String value;
child = configuration.getChild(LINK_CONTENT_TYPE_CONFIG, false);
if (child != null) {
value = child.getValue();
if (value != null && value.length() > 0) {
this.linkContentType = value.trim();
}
}
child = configuration.getChild(LINK_VIEW_QUERY_CONFIG, false);
if (child != null) {
value = child.getValue();
if (value != null && value.length() > 0) {
this.linkViewQuery = value.trim();
}
}
/* FIXME: Also delete this if you delete the fields above.
child = configuration.getChild(USER_AGENT_CONFIG, false);
if (child != null) {
value = child.getValue();
if (value != null && value.length() > 0) {
this.userAgent = value;
}
}
child = configuration.getChild(ACCEPT_CONFIG, false);
if (child != null) {
value = child.getValue();
if (value != null && value.length() > 0) {
this.accept = value;
}
}
*/
}
public void setup(SourceResolver resolver, Map objectModel, String src, Parameters par)
throws ProcessingException, SAXException, IOException {
super.setup(resolver, objectModel, src, par);
/* Create a reusable attributes for creating nodes */
this.attributes = new AttributesImpl();
// already done in configure...
//excludeCrawlingURL = new HashSet();
//this.setDefaultExcludeFromCrawling();
}
/**
* Generate XML data.
*
* @throws SAXException
* if an error occurs while outputting the document
* @throws ProcessingException
* if the requsted URI wasn't found
*/
public void generate()
throws SAXException, ProcessingException {
try {
crawled = new HashSet();
linksToProcess = new HashSet();
URL root = new URL(source);
linksToProcess.add(new Link(root, ""));
if (getLogger().isDebugEnabled()) {
getLogger().debug("crawl URL " + root);
}
this.contentHandler.startDocument();
this.contentHandler.startPrefixMapping(PREFIX, URI);
attributes.clear();
super.contentHandler.startElement(URI, TOP_NODE_NAME, PREFIX + ':' + TOP_NODE_NAME, attributes);
while (linksToProcess.size() > 0) {
Iterator i = linksToProcess.iterator();
if (i.hasNext()) {
// fetch a URL
Link link = (Link) i.next();
URL url = link.getURL();
// remove it from the to-do list
linksToProcess.remove(link);
String new_url_link = processURL(url, link.getReferrer());
// calc all links from this url
if (new_url_link != null) {
List url_links = getLinksFromConnection(new_url_link, url);
if (url_links != null) {
// add links of this url to the to-do list
linksToProcess.addAll(url_links);
}
}
}
}
super.contentHandler.endElement(URI, TOP_NODE_NAME, PREFIX + ':' + TOP_NODE_NAME);
this.contentHandler.endPrefixMapping(PREFIX);
this.contentHandler.endDocument();
} catch (IOException ioe) {
getLogger().warn("Could not read source ", ioe);
throw new ResourceNotFoundException("Could not read source ", ioe);
}
}
/**
* Default exclude patterns.
* <p>
* By default URLs matching following patterns are excluded:
* </p>
* <ul>
* <li>.*\\.gif(\\?.*)?$ - exclude gif images</li>
* <li>.*\\.png(\\?.*)?$ - exclude png images</li>
* <li>.*\\.jpe?g(\\?.*)?$ - exclude jpeg images</li>
* <li>.*\\.js(\\?.*)?$ - exclude javascript </li>
* <li>.*\\.css(\\?.*)?$ - exclude cascaded stylesheets</li>
* </ul>
*
* @since
*/
private void setDefaultExcludeFromCrawling() {
String[] EXCLUDE_FROM_CRAWLING_DEFAULT = {
".*\\.gif(\\?.*)?$",
".*\\.png(\\?.*)?$",
".*\\.jpe?g(\\?.*)?$",
".*\\.js(\\?.*)?$",
".*\\.css(\\?.*)?$"
};
for (int i = 0; i < EXCLUDE_FROM_CRAWLING_DEFAULT.length; i++) {
String pattern = EXCLUDE_FROM_CRAWLING_DEFAULT[i];
try {
excludeCrawlingURL.add(new RE(pattern));
} catch (RESyntaxException rese) {
getLogger().error("Cannot create excluding regular-expression for " +
pattern, rese);
}
}
}
/**
* Retrieve a list of links of a url
*
* @param url_link_string url for requesting links, it is assumed that
* url_link_string queries the cocoon view links, ie of the form
* <code>http://host/foo/bar?cocoon-view=links</code>
* @param url_of_referrer base url of which links are requested, ie of the form
* <code>http://host/foo/bar</code>
* @return List of links from url_of_referrer, as result of requesting url
* url_link_string
*/
protected List getLinksFromConnection(String url_link_string, URL url_of_referrer) {
List url_links = null;
BufferedReader br = null;
try {
URL url_link = new URL(url_link_string);
URLConnection conn = url_link.openConnection();
String content_type = conn.getContentType();
if (content_type == null) {
getLogger().warn("No content type available for " + String.valueOf(url_link_string));
// caller checks if null
return url_links;
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("Content-type: " + content_type);
}
if (content_type.equals(linkContentType) ||
content_type.startsWith(linkContentType + ";")) {
url_links = new ArrayList();
InputStream is = conn.getInputStream();
br = new BufferedReader(new InputStreamReader(is));
// content is supposed to be a list of links,
// relative to current URL
String line;
String referrer = url_of_referrer.toString();
while ((line = br.readLine()) != null) {
URL new_url = new URL(url_link, line);
boolean add_url = true;
// don't add new_url twice
if (add_url) {
add_url &= !url_links.contains(new_url);
}
// don't add new_url if it has been crawled already
if (add_url) {
add_url &= !crawled.contains(new_url.toString());
}
Link new_link = new Link(new_url, referrer);
if (add_url) {
add_url &= !linksToProcess.contains(new_link);
}
// don't add if is not matched by existing include definition
if (add_url) {
add_url &= isIncludedURL(new_url.toString());
}
if (add_url) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Add URL: " + new_url.toString());
}
url_links.add(new_link);
}
}
// now we have a list of URL which should be examined
}
} catch (IOException ioe) {
getLogger().warn("Problems get links of " + url_link_string, ioe);
} finally {
// explictly close the stream
if (br != null) {
try {
br.close();
br = null;
} catch (IOException ignored) {
}
}
}
return url_links;
}
/**
* Generate xml attributes of a url, calculate url for retrieving links
*
* @param url to process
* @param referrer of the url
* @return String url for retrieving links, or null if url is an excluded-url,
* and not an included-url.
*/
protected String processURL(URL url, String referrer) throws SAXException {
if (getLogger().isDebugEnabled()) {
getLogger().debug("getLinks URL " + url);
}
String result = null;
// don't try to investigate a url which has been crawled already
if (crawled.contains(url.toString())) {
return null;
}
// mark it as crawled
crawled.add(url.toString());
attributes.clear();
attributes.addAttribute("", HREF_ATTR_NAME,
HREF_ATTR_NAME, "CDATA", url.toString());
attributes.addAttribute("", REFERRER_ATTR_NAME,
REFERRER_ATTR_NAME, "CDATA", referrer);
// Output url, referrer, content-type, status, message for traversable url's
HttpURLConnection h = null;
try {
URLConnection links_url_connection = url.openConnection();
h = (HttpURLConnection) links_url_connection;
String content_type = links_url_connection.getContentType();
attributes.addAttribute("", CONTENT_ATTR_NAME,
CONTENT_ATTR_NAME, "CDATA",
content_type);
attributes.addAttribute("", MESSAGE_ATTR_NAME,
MESSAGE_ATTR_NAME, "CDATA",
h.getResponseMessage());
attributes.addAttribute("", STATUS_ATTR_NAME,
STATUS_ATTR_NAME, "CDATA",
String.valueOf(h.getResponseCode()));
} catch (IOException ioe) {
attributes.addAttribute("", MESSAGE_ATTR_NAME,
MESSAGE_ATTR_NAME, "CDATA",
ioe.getMessage());
} finally {
if (h != null) {
h.disconnect();
}
}
// don't try to get links of a url which is excluded from crawling
// try to get links of a url which is included for crawling
if (!isExcludedURL(url.toString()) && isIncludedURL(url.toString())) {
// add prefix and query to get data from the linkserializer.
result = url.toExternalForm()
+ ((url.toExternalForm().indexOf("?") == -1) ? "?" : "&")
+ linkViewQuery;
}
super.contentHandler.startElement(URI, LINK_NODE_NAME, PREFIX + ':' + LINK_NODE_NAME, attributes);
super.contentHandler.endElement(URI, LINK_NODE_NAME, PREFIX + ':' + LINK_NODE_NAME);
return result;
}
/**
* check if URL is a candidate for indexing
*
* @param url Description of Parameter
* @return The excludedURL value
* @since
*/
private boolean isExcludedURL(String url) {
// by default include URL for crawling
if (excludeCrawlingURL == null) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("exclude no URL " + url);
}
return false;
}
final String s = url;
Iterator i = excludeCrawlingURL.iterator();
while (i.hasNext()) {
RE pattern = (RE) i.next();
if (pattern.match(s)) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("exclude URL " + url);
}
return true;
}
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("exclude not URL " + url);
}
return false;
}
/**
* check if URL is a candidate for indexing
*
* @param url Description of Parameter
* @return The includedURL value
* @since
*/
private boolean isIncludedURL(String url) {
// by default include URL for crawling
if (includeCrawlingURL == null) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("include all URL " + url);
}
return true;
}
final String s = url;
Iterator i = includeCrawlingURL.iterator();
while (i.hasNext()) {
RE pattern = (RE) i.next();
if (pattern.match(s)) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("include URL " + url);
}
return true;
}
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("include not URL " + url);
}
return false;
}
public void recycle() {
super.recycle();
this.attributes = null;
}
}