从几英里远可以看到您没有在Class.forName

It's visible from a (few) mile(s) away you are not using the custom classloader beside Class.forName

由于已加载当前类MyProgram的类加载器尝试加载org.eclipse.swt.graphics.Point，所以发生了ClassNoDefFoundError.

The ClassNoDefFoundError occurs since the classloader that has loaded current class MyProgram attempts to load org.eclipse.swt.graphics.Point.

您需要通过Class.forName加载另一个类(称为启动器)，然后从那里开始-实现一些接口(甚至可以运行)并调用它.

You need to load another class (call it launcher) via Class.forName and then start from there - implement some interface (even runnable will do) and call it.

编辑

如何做，这是一个简单的场景.
1.创建另一个名为mp.loader.Launcher的类，该类实现了这样的Runnable.

How to do it, a simplistic scenario.
1. Create another class called mp.loader.Launcher that implements Runnable like that.

public class Launcher implements Runnable{
public void run(){
  org.eclipse.swt.graphics.Point pt = new org.eclipse.swt.graphics.Point(0, 0);
  //whatever, start from here.
}
}

2.将其放在另一个名为swt-loader.jar的jar中.

2. Place it in another jar called swt-loader.jar.

在MyProgram类中使用:

in MyProgram class use:

loader.addJarToClasspath("swt-loader.jar");
Runnable r = (Runnable) Class.forName("mp.loader.Launcher", true, loader);
r.run();//there you have