Thread: No such method, help

Hello, I am newer here.

I am have error in my java code.

Class aClass = new URLClassLoader(new URL[] { urlJarFile }).loadClass( classInJar );
Constructor constructor = aClass.getConstructor(new Class[] { JFrame.class, File.class, Proxy.class, PasswordAuthentication.class, java.lang.String.class,Integer.class });

external Jar

public class Launcher
{ 
 
...
 
public Launcher(JFrame frame, File workingDirectory, Proxy proxy, PasswordAuthentication proxyAuth, String[] args, Integer bootstrapVersion) {
  /*
     CODE
  */
}
 
 
}

I got this error

Unable to start: java.lang.NoSuchMethodException

can help me?

Gretings