Fix typo in reference manual

Author: sbrannen

src/docs/asciidoc/languages/dynamic-languages.adoc

@@ -480,9 +480,9 @@ Finally, the following small application exercises the preceding configuration:
 
 	public class Main {
 
-		public static void Main(String[] args) {
+		public static void main(String[] args) {
 			ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
-			Calculator calc = (Calculator) ctx.getBean("calculator");
+			Calculator calc = ctx.getBean("calculator", Calculator.class);
 			System.out.println(calc.add(2, 8));
 		}
 	}