PatternSyntaxException when trying to access Website with HtmlUnit

Question

I'm currently trying to acces a Webpage in Javacode using HtmlUnit. The Page has a Button, which opens a new Page when clicked. But when I try to click it, the compiler throws this exception which can be found in the attached image. As far as I understand, it has something to do with illegal escape sequences in the page's Html code.

Here is my code so far:

try(WebClient client = new WebClient(BrowserVersion.CHROME)){

    client.getOptions().setCssEnabled(false);
    WebRequest webRequest = new WebRequest(url);
    webRequest.setCharset("utf-8");
    HtmlPage entrypage = client.getPage(webRequest);
    HtmlInput dwnld = (HtmlInput) entrypage.getElementById("btn_download");

    long millis =  System.currentTimeMillis();

    while (System.currentTimeMillis() <= millis+11000) {
        //Do nothing, just wait 11 seconds
    }

    if (dwnld != null) {
        System.out.println("Found btn_download");
        dwnld.click();
    }


} catch (FailingHttpStatusCodeException | IOException e ) {
    // TODO Auto-generated catch block

    e.printStackTrace();
}

Ideas anyone?

Here's the exception:

java.util.regex.PatternSyntaxException: Illegal octal escape sequence near index 2
\0+$
  ^
    at java.util.regex.Pattern.error(Pattern.java:1955)
    at java.util.regex.Pattern.o(Pattern.java:3192)
    at java.util.regex.Pattern.escape(Pattern.java:2300)
    at java.util.regex.Pattern.atom(Pattern.java:2198)
    at java.util.regex.Pattern.sequence(Pattern.java:2079)
    at java.util.regex.Pattern.expr(Pattern.java:1996)
    at java.util.regex.Pattern.compile(Pattern.java:1696)
    at java.util.regex.Pattern.<init>(Pattern.java:1351)
    at java.util.regex.Pattern.compile(Pattern.java:1054)
    at com.gargoylesoftware.htmlunit.javascript.regexp.HtmlUnitRegExpProxy.doAction(HtmlUnitRegExpProxy.java:102)
    at com.gargoylesoftware.htmlunit.javascript.regexp.HtmlUnitRegExpProxy.action(HtmlUnitRegExpProxy.java:74)
    at net.sourceforge.htmlunit.corejs.javascript.NativeString.execIdCall(NativeString.java:455)
    at net.sourceforge.htmlunit.corejs.javascript.IdFunctionObject.call(IdFunctionObject.java:89)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpretLoop(Interpreter.java:1531)
    at net.sourceforge.htmlunit.corejs.javascript.Interpreter.interpret(Interpreter.java:798)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.call(InterpretedFunction.java:105)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.doTopCall(ContextFactory.java:411)
    at com.gargoylesoftware.htmlunit.javascript.HtmlUnitContextFactory.doTopCall(HtmlUnitContextFactory.java:309)
    at net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3057)
    at net.sourceforge.htmlunit.corejs.javascript.InterpretedFunction.exec(InterpretedFunction.java:115)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$3.doRun(JavaScriptEngine.java:724)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine$HtmlUnitContextAction.run(JavaScriptEngine.java:832)
    at net.sourceforge.htmlunit.corejs.javascript.Context.call(Context.java:620)
    at net.sourceforge.htmlunit.corejs.javascript.ContextFactory.call(ContextFactory.java:513)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:733)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.execute(JavaScriptEngine.java:708)
    at com.gargoylesoftware.htmlunit.html.HtmlPage.executeJavaScriptIfPossible(HtmlPage.java:982)
    at com.gargoylesoftware.htmlunit.html.HtmlScript.executeInlineScriptIfNeeded(HtmlScript.java:351)
    at com.gargoylesoftware.htmlunit.html.HtmlScript.executeScriptIfNeeded(HtmlScript.java:411)
    at com.gargoylesoftware.htmlunit.html.HtmlScript$3.execute(HtmlScript.java:276)
    at com.gargoylesoftware.htmlunit.html.HtmlScript.onAllChildrenAddedToPage(HtmlScript.java:290)
    at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.endElement(HTMLParser.java:793)
    at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
    at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.endElement(HTMLParser.java:751)
    at org.cyberneko.html.HTMLTagBalancer.callEndElement(HTMLTagBalancer.java:1170)
    at org.cyberneko.html.HTMLTagBalancer.endElement(HTMLTagBalancer.java:1072)
    at org.cyberneko.html.filters.DefaultFilter.endElement(DefaultFilter.java:206)
    at org.cyberneko.html.filters.NamespaceBinder.endElement(NamespaceBinder.java:330)
    at org.cyberneko.html.HTMLScanner$ContentScanner.scanEndElement(HTMLScanner.java:3126)
    at org.cyberneko.html.HTMLScanner$ContentScanner.scan(HTMLScanner.java:2093)
    at org.cyberneko.html.HTMLScanner.scanDocument(HTMLScanner.java:920)
    at org.cyberneko.html.HTMLConfiguration.parse(HTMLConfiguration.java:499)
    at org.cyberneko.html.HTMLConfiguration.parse(HTMLConfiguration.java:452)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.parse(HTMLParser.java:1017)
    at com.gargoylesoftware.htmlunit.html.HTMLParser.parse(HTMLParser.java:248)
    at com.gargoylesoftware.htmlunit.html.HTMLParser.parseHtml(HTMLParser.java:194)
    at com.gargoylesoftware.htmlunit.DefaultPageCreator.createHtmlPage(DefaultPageCreator.java:268)
    at com.gargoylesoftware.htmlunit.DefaultPageCreator.createPage(DefaultPageCreator.java:156)
    at com.gargoylesoftware.htmlunit.WebClient.loadWebResponseInto(WebClient.java:471)
    at com.gargoylesoftware.htmlunit.WebClient.loadDownloadedResponses(WebClient.java:2110)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.doProcessPostponedActions(JavaScriptEngine.java:875)
    at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.processPostponedActions(JavaScriptEngine.java:962)
    at com.gargoylesoftware.htmlunit.html.HtmlElement.click(HtmlElement.java:1327)
    at com.gargoylesoftware.htmlunit.html.HtmlElement.click(HtmlElement.java:1270)
    at com.gargoylesoftware.htmlunit.html.HtmlElement.click(HtmlElement.java:1218)
    at src.Hosts$1.exctractFileLinkFrom(Hosts.java:44)
    at src.TestMain.main(TestMain.java:10)

Hey there. First, there's no attached image. Second, don't put error messages in images. Copy/Paste the exact error message, removing sensible information if necessary. Thanks, and good luck! — Félix Adriyel Gagnon-Grenier, May 14 '15 at 12:47
What is the exception? Rather than linking to a picture, add it as text. Also, please provide the relevant input that causes the exception. — Magnilex, May 14 '15 at 12:48
Can you post the website URL to compare the regular expression with real browsers? — Ahmed Ashour, May 14 '15 at 17:41
http://streamcloud.eu/bny4w1ji3lhj/_HorribleSubs__Death_Parade_-_01__720p_.mkv.html — PooBucket, May 15 '15 at 07:04
See my answer below. I solved this myself already. But still thank you :) — PooBucket, May 15 '15 at 15:50

score 0 · Answer 1 · answered May 15 '15 at 07:13

Possible solution?!

It is possible that the Error here does not lie in the frameworks Htmlparsing. My sugggestion is, that not the HtmlUnit framework itself is unable to parse illegal escape sequences but it's logger might be.

I didn't intended to solve the problem this way, but when I changed the loggers level to SEVERE to clean up my console output, there is no such exception being thrown.

Logger.getLogger("com.gargoylesoftware.htmlunit").setLevel(java.util.logging.Level.SEVERE);
Logger.getLogger("org.apache.http").setLevel(java.util.logging.Level.SEVERE);

Is my suggestion here correct or is this just coincidence?

PatternSyntaxException when trying to access Website with HtmlUnit

1 Answers1

Possible solution?!