/**
* Performs a parse by iterating through a List of preferred {@link Parser}s until a successful
* parse is performed and a {@link Parse} object is returned. If the parse is unsuccessful, a
* message is logged to the <code>WARNING</code> level, and an empty parse is returned.
*
* @throws ParserNotFound If there is no suitable parser found.
* @throws ParseException If there is an error parsing.
*/
public Parse parse(String url, WebPage page) throws ParserNotFound, ParseException {
Parser[] parsers = null;
String contentType = TableUtil.toString(page.getContentType());
parsers = this.parserFactory.getParsers(contentType, url);
for (int i = 0; i < parsers.length; i++) {
if (LOG.isDebugEnabled()) {
LOG.debug("Parsing [" + url + "] with [" + parsers[i] + "]");
}
Parse parse = null;
if (maxParseTime != -1) parse = runParser(parsers[i], url, page);
else parse = parsers[i].getParse(url, page);
if (parse != null && ParseStatusUtils.isSuccess(parse.getParseStatus())) {
return parse;
}
}
LOG.warn("Unable to successfully parse content " + url + " of type " + contentType);
return ParseStatusUtils.getEmptyParse(
new ParseException("Unable to successfully parse content"), null);
}
/**
* Parses given web page and stores parsed content within page. Puts a meta-redirect to outlinks.
*
* @param key
* @param page
*/
public void process(String key, WebPage page) {
String url = TableUtil.unreverseUrl(key);
byte status = page.getStatus().byteValue();
if (status != CrawlStatus.STATUS_FETCHED) {
if (LOG.isDebugEnabled()) {
LOG.debug("Skipping " + url + " as status is: " + CrawlStatus.getName(status));
}
return;
}
Parse parse;
try {
parse = parse(url, page);
} catch (ParserNotFound e) {
// do not print stacktrace for the fact that some types are not mapped.
LOG.warn("No suitable parser found: " + e.getMessage());
return;
} catch (final Exception e) {
LOG.warn("Error parsing: " + url + ": " + StringUtils.stringifyException(e));
return;
}
if (parse == null) {
return;
}
org.apache.nutch.storage.ParseStatus pstatus = parse.getParseStatus();
page.setParseStatus(pstatus);
if (ParseStatusUtils.isSuccess(pstatus)) {
if (pstatus.getMinorCode() == ParseStatusCodes.SUCCESS_REDIRECT) {
String newUrl = ParseStatusUtils.getMessage(pstatus);
int refreshTime = Integer.parseInt(ParseStatusUtils.getArg(pstatus, 1));
try {
newUrl = normalizers.normalize(newUrl, URLNormalizers.SCOPE_FETCHER);
if (newUrl == null) {
LOG.warn("redirect normalized to null " + url);
return;
}
try {
newUrl = filters.filter(newUrl);
} catch (URLFilterException e) {
return;
}
if (newUrl == null) {
LOG.warn("redirect filtered to null " + url);
return;
}
} catch (MalformedURLException e) {
LOG.warn("malformed url exception parsing redirect " + url);
return;
}
page.getOutlinks().put(new Utf8(newUrl), new Utf8());
page.getMetadata().put(FetcherJob.REDIRECT_DISCOVERED, TableUtil.YES_VAL);
if (newUrl == null || newUrl.equals(url)) {
String reprUrl =
URLUtil.chooseRepr(url, newUrl, refreshTime < FetcherJob.PERM_REFRESH_TIME);
if (reprUrl == null) {
LOG.warn("reprUrl==null for " + url);
return;
} else {
page.setReprUrl(new Utf8(reprUrl));
}
}
} else {
page.setText(new Utf8(parse.getText()));
page.setTitle(new Utf8(parse.getTitle()));
ByteBuffer prevSig = page.getSignature();
if (prevSig != null) {
page.setPrevSignature(prevSig);
}
final byte[] signature = sig.calculate(page);
page.setSignature(ByteBuffer.wrap(signature));
if (page.getOutlinks() != null) {
page.getOutlinks().clear();
}
final Outlink[] outlinks = parse.getOutlinks();
int outlinksToStore = Math.min(maxOutlinks, outlinks.length);
String fromHost;
if (ignoreExternalLinks) {
try {
fromHost = new URL(url).getHost().toLowerCase();
} catch (final MalformedURLException e) {
fromHost = null;
}
} else {
fromHost = null;
}
int validCount = 0;
for (int i = 0; validCount < outlinksToStore && i < outlinks.length; i++) {
String toUrl = outlinks[i].getToUrl();
try {
toUrl = normalizers.normalize(toUrl, URLNormalizers.SCOPE_OUTLINK);
toUrl = filters.filter(toUrl);
} catch (MalformedURLException e2) {
continue;
} catch (URLFilterException e) {
continue;
}
if (toUrl == null) {
continue;
}
Utf8 utf8ToUrl = new Utf8(toUrl);
if (page.getOutlinks().get(utf8ToUrl) != null) {
// skip duplicate outlinks
continue;
}
String toHost;
if (ignoreExternalLinks) {
try {
toHost = new URL(toUrl).getHost().toLowerCase();
} catch (final MalformedURLException e) {
toHost = null;
}
if (toHost == null || !toHost.equals(fromHost)) { // external links
continue; // skip it
}
}
validCount++;
page.getOutlinks().put(utf8ToUrl, new Utf8(outlinks[i].getAnchor()));
}
Utf8 fetchMark = Mark.FETCH_MARK.checkMark(page);
if (fetchMark != null) {
Mark.PARSE_MARK.putMark(page, fetchMark);
}
}
}
}