The Graphics2D object was not present in Java 1.1 so if you *have* to make an applet or AWT program support Java 1.1 (i.e. not import any 1.2+ classes) but you still want to use advanced featured such as anti-aliasing when the user has a 1.2+ JRE then here is how to detect and enable those features using reflection:
public static void enableAntialiasing(Graphics g, boolean shapeAntiAlias, boolean textAntiAlias)
{
 try
 {
   String nameGraphics2D = "java.awt.Graphics2D";
   String nameRenderingHints = "java.awt.RenderingHints";
   String nameRenderingHintsKey = "java.awt.RenderingHints$Key";

   Class classGraphics2D = null;

   try
   {
     classGraphics2D = Class.forName(nameGraphics2D);
   }
   catch (ClassNotFoundException e)
   {
   }
   catch (NoClassDefFoundError e)
   {
   }

   if (classGraphics2D != null)
   {
     System.out.println(nameGraphics2D + " is available");

     Class classRenderingHints = null;

     try
     {
       classRenderingHints = Class.forName(nameRenderingHints);
     }
     catch (ClassNotFoundException e)
     {
     }
     catch (NoClassDefFoundError e)
     {
     }

     if (classRenderingHints != null)
     {
       System.out.println(nameRenderingHints + " is available");

       Class classRenderingHintsKey = null;

       try
       {
         classRenderingHintsKey = Class.forName(nameRenderingHintsKey);
       }
       catch (ClassNotFoundException e)
       {
       }
       catch (NoClassDefFoundError e)
       {
       }

       if (classRenderingHintsKey != null)
       {
         System.out.println(nameRenderingHintsKey + " is available");

         if (shapeAntiAlias)
         {
           Field rhKeyAntiAliasing = classRenderingHints.getField("KEY_ANTIALIASING");
           Field rhValueAntiAliasingOn = classRenderingHints.getField("VALUE_ANTIALIAS_ON");

           Method method = classGraphics2D.getMethod("setRenderingHint", new Class[] { classRenderingHintsKey, Object.class });
           method.invoke(g, new Object[] { rhKeyAntiAliasing.get(null), rhValueAntiAliasingOn.get(null) });
         }

         if (textAntiAlias)
         {
           Field rhKeyTextAntiAliasing = classRenderingHints.getField("KEY_TEXT_ANTIALIASING");
           Field rhValueTextAntiAliasingOn = classRenderingHints.getField("VALUE_TEXT_ANTIALIAS_ON");

           Method method = classGraphics2D.getMethod("setRenderingHint", new Class[] { classRenderingHintsKey, Object.class });
           method.invoke(g, new Object[] { rhKeyTextAntiAliasing.get(null), rhValueTextAntiAliasingOn.get(null) });
         }
       }
     }
   }
 }
 catch (Exception e)
 {
   System.out.println("Could not set antialiasing");
   e.printStackTrace();
 }
}