1    package bookExamples.ch24Reflection; 
2     
3    import gui.In; 
4     
5    import java.util.StringTokenizer; 
6    import java.lang.reflect.Method; 
7    import java.lang.reflect.InvocationTargetException; 
8     
9    /** 
10    * DocJava, Inc. 
11    * http://www.docjava.com 
12    * Programmer: dlyon 
13    * Date: Oct 6, 2004 
14    * Time: 8:33:48 PM 
15    */ 
16   public class Ex3 { 
17       // prompt the user for a class name that has a main 
18       // method 
19       public static void main(String[] args) { 
20           try { 
21               executeMainCli(); 
22           } catch (ClassNotFoundException e) { 
23               e.printStackTrace(); 
24           } catch (NoSuchMethodException e) { 
25               e.printStackTrace(); 
26           } catch (IllegalAccessException e) { 
27               e.printStackTrace(); 
28           } catch (InvocationTargetException e) { 
29               e.printStackTrace(); 
30           } 
31       } 
32    
33       private static void executeMainCli() throws 
34               ClassNotFoundException, 
35               NoSuchMethodException, 
36               IllegalAccessException, 
37               InvocationTargetException { 
38           String className = In.getString("enter a class name that has a main"); 
39           String arguments = In.getString("enter the arguments for the main method"); 
40           String argsArray[] = getArray(arguments); 
41           Class c = Class.forName(className); 
42           Class parameterType = argsArray.getClass(); 
43           // this is the part you do for homework!; 
44           String name = "noArgs"; // alter this so it has args and uses main. 
45           Method main = c.getMethod(name, new Class[]{}); 
46           main.invoke(null,null); 
47    
48       } 
49       private static String [] getArray(String s) { 
50           StringTokenizer st = new StringTokenizer(s); 
51           int n = st.countTokens(); 
52           String sa[] = new String[n]; 
53           for (int i=0; i < n; i++) 
54               sa[i] = st.nextToken(); 
55           return sa; 
56       } 
57   } 
58