OkHttp NoClassDefFoundError: okhttp3/Authenticator

[Markus Jelsma]

Hello,

With a 1.18 checkout i am trying the okhttp plugin. I couldn't get it to
work on 1.15 due to another NoClassDefFoundError, and now with 1.18, it
still doesn't work and throws another NoClassDefFoundError.

java.lang.NoClassDefFoundError: okhttp3/Authenticator
        at java.base/java.lang.Class.getDeclaredConstructors0(Native Method)
        at
java.base/java.lang.Class.privateGetDeclaredConstructors(Class.java:3137)
        at java.base/java.lang.Class.getConstructor0(Class.java:3342)
        at java.base/java.lang.Class.getConstructor(Class.java:2151)
        at
org.apache.nutch.plugin.Extension.getExtensionInstance(Extension.java:164)
        at
org.apache.nutch.protocol.ProtocolFactory.getProtocolInstanceByExtension(ProtocolFactory.java:177)
        at
org.apache.nutch.protocol.ProtocolFactory.getProtocol(ProtocolFactory.java:146)
        at
org.apache.nutch.fetcher.FetcherThread.run(FetcherThread.java:308)
Caused by: java.lang.ClassNotFoundException: okhttp3.Authenticator
        at
java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
        at
org.apache.nutch.plugin.PluginClassLoader.loadClass(PluginClassLoader.java:104)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        ... 8 more

Any ideas what's going on?

Thanks,
Markus