这个问题是如此受欢迎，但是我找不到避免“ java.lang.ClassnotFoundException”的方法。

我已经实现了一种动态加载某些外部类的方法（提取战争文件后得到）

private void OnLoaded(object sender,RoutedEventArgs e)
{
    var currentParent = Parent;

    while (currentParent != null && !(currentParent is Window))
    {
        currentParent = VisualTreeHelper.GetParent(currentParent);
    }

    if (currentParent is Window parentWindow)
    {
        parentWindow.ResizeMode = ResizeMode.NoResize;
    }
}

相同的异常仍然一次又一次地出现。这是堆栈跟踪：

  Class<?> classGetter() {
    URL url;
    Class<?>  cls = null;
    try {
        String classname=new Substringer(entireFilePath.getName(),5).output;
        String classpath=new 
        Substringer(entireFilePath.getabsolutePath(),5+classname.length()).output;
        File classDirPath = new File(classpath);
        url = classDirPath.toURI().toURL();
        URL[] urls = new URL[]{url};
        URLClassLoader cl = new URLClassLoader(urls); 
        cls = cl.loadClass(packageGetter()+"."+classname);
        cl.close();
    } catch (ClassnotFoundException | IOException e) {
        e.printStackTrace();
    }
    return cls;
}