java.lang.NoClassDefFoundError: org/eclipse/jetty/websocket/api/Session

My code is very simple:

public class HtmlUnitDriverTest {
    public static void main(String[] args) {
        final WebClient webClient = new WebClient();
    }
}

When use htmlunit-driver 2.20, it’s ok. But when i update to 2.23, i meet the following error:

Exception in thread “main” java.lang.NoClassDefFoundError: org/eclipse/jetty/websocket/api/Session at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2625) at java.lang.Class.getDeclaredMethods(Class.java:1868) at com.gargoylesoftware.htmlunit.javascript.configuration.AbstractJavaScriptConfiguration.process(AbstractJavaScriptConfiguration.java:197) at com.gargoylesoftware.htmlunit.javascript.configuration.AbstractJavaScriptConfiguration.getClassConfiguration(AbstractJavaScriptConfiguration.java:172) at com.gargoylesoftware.htmlunit.javascript.configuration.AbstractJavaScriptConfiguration.buildUsageMap(AbstractJavaScriptConfiguration.java:79) at com.gargoylesoftware.htmlunit.javascript.configuration.AbstractJavaScriptConfiguration.<init>(AbstractJavaScriptConfiguration.java:59) at com.gargoylesoftware.htmlunit.javascript.configuration.JavaScriptConfiguration.<init>(JavaScriptConfiguration.java:597) at com.gargoylesoftware.htmlunit.javascript.configuration.JavaScriptConfiguration.getInstance(JavaScriptConfiguration.java:613) at com.gargoylesoftware.htmlunit.javascript.JavaScriptEngine.<init>(JavaScriptEngine.java:133) at com.gargoylesoftware.htmlunit.WebClient.init(WebClient.java:239) at com.gargoylesoftware.htmlunit.WebClient.<init>(WebClient.java:213) at com.gargoylesoftware.htmlunit.WebClient.<init>(WebClient.java:204) at HtmlUnitDriverTest.main(HtmlUnitDriverTest.java:11) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) Caused by: java.lang.ClassNotFoundException: org.eclipse.jetty.websocket.api.Session at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) … 19 more

I compare my pom.xml file of 2.20 and 2.23, my 2.20 pom:

<dependency>
    <groupId>net.sourceforge.htmlunit</groupId>
    <artifactId>htmlunit</artifactId>
    <version>2.20</version>
</dependency>

the 2.23 pom:

<dependency>
    <groupId>net.sourceforge.htmlunit</groupId>
    <artifactId>htmlunit</artifactId>
    <version>2.23</version>
    <exclusions>
        <exclusion>
            <groupId>org.eclipse.jetty.websocket</groupId>
            <artifactId>websocket-client</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Do I need to manually add the dependency for jetty? Please help me, thanks a lot.

[ThrawnCA]

I think I’ve found it!

You haven’t specified the BrowserVersion that your WebClient will emulate, so it defaults to the best-supported version - which is currently Chrome. And when your WebClient initialises its JavaScript support, the configuration class (com.gargoylesoftware.htmlunit.javascript.configuration.AbstractJavaScriptConfiguration, if you’re wondering) will trawl the annotations on all known JavaScript objects (the list is in com.gargoylesoftware.htmlunit.javascript.configuration.JavaScriptConfiguration) to check whether they support the selected BrowserVersion. And WebSocket uses the JsxClass annotation with default values - which support Chrome. So, by default, it will attempt to load WebSocket support.

So yes, you probably should add the websocket-client dependency. I assume that it was dropped so that clients using a different browser version don’t have to include it - although since the default is to rely on it, I’d call that a poor choice. If someone really doesn’t want that JAR, they can specifically exclude it themselves.

[snicoll]

Can you just add the dependency manually, when HtmlUnitDriver is referenced?

No, I don’t use htmlunit but Spring Boot provides auto-configuration for the WebClient. If a user of Spring Boot adds htmlunit on the classpath, we auto-configure the WebClient and it will throw this exception unless websocket-client is manually added. We won’t upgrade until this issue is fixed as we cannot shield our users from this (they add the dependency themselves).

A bug fix release in the coming couple of weeks would be very appreciated.