如何从另一个Java类加载一个？

Question

SEE THIS link for the solution to the problem

I am doing a project where I have a drop down list, which when an option is selected on the list, it loads an applet with custom settings. The name of the main class of the applet is SteadyStateFusionDemo. I don't why I'm having so much trouble with this because I know that I have to use a ClassLoader, but quite frankly I don't know how to do this.

Here is the code for my dropdown list. I want to link from the option on the list to the other class.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.ClassLoader;
import ssfd.SteadyStateFusionDemo;

//**Creates Drop down Menu where choices show up in the box next to it//
//After one of these is selected, it loads the SteadyStateFusionDemo class//
//It also transmits a variable to the VariableStorage class, so that those//
//values can be used in operating the Tokamak.**//
public class ComboBox{
   JComboBox combo;
   JTextField txt;
   public static void main(String[] args) {
      ComboBox b = new ComboBox();
   }

   public ComboBox(){
        String course[] = {"NSTX","LTX","ITER"};
        JFrame frame = new JFrame("Creating a JComboBox Component");
        JPanel panel = new JPanel();
        combo = new JComboBox(course);
        combo.setBackground(Color.gray);
        combo.setForeground(Color.red);
        txt = new JTextField(10);
        panel.add(combo);
        panel.add(txt);
        frame.add(panel);
        combo.addItemListener(new ItemListener(){
        public void itemStateChanged(ItemEvent ie){
          String str = (String)combo.getSelectedItem();

     //Where the ItemListener interprets the choice, and then loads the SteadyStateFusionDemo class.

              if (str == "NSTX") {
                txt.setText("A");
          //loads SteadyStateFusionDemo, NSTX version

      }
              if (str == "ITER") {
              txt.setText("B");
             //loadsSteadyStateFusionDemo, ITER version




      }
              if (str == "LTX") {
              txt.setText("C");
              //loads SteadyStateFusionDemo, LTX version

      }

There is more after this but it isn't relevant to the question.

Can someone help me figure out how to link the two classes? The second class is in a different package and it doesn't use a static method. I have practically looked all over the Internet to find the solution, but alas no luck. :(

Answer 1

You can dynamically load classes by using Class.forName as in the following example, would this solve your problem?

Class<?> clazz = Class.forName("ssfd.SteadyStateFusionDemo");
SteadyStateFusionDemo ssfd = clazz.newInstance();