Source:
http://oldsunweb.ireland/~ab23780/mustang/282/j2se/webrev/src/share/classes/sun/instrument/InstrumentationImpl.java.html
<your code>
166         try {
167             m = javaAgentClass.getMethod( methodname,
168                                           new Class[] { 
169                                               String.class,
170                                               java.lang.instrument.Instrumentation.class
171                                           }
172                                         );
173             twoArgAgent = true;
174         } catch (NoSuchMethodException x) {
175             // remember the NoSuchMethodException 
176             firstExc = x;
177         }
178 
179         // check for the 1-arg method
180         if (m == null) {
181             try {
182                 m = javaAgentClass.getMethod(methodname, new Class[] { String.class });
183             } catch (NoSuchMethodException x) {
184                 // Neither method exists so we throw the first NoSuchMethodException
185                 // as per 5.0
186                 throw firstExc;
187             }
188         }
189 
190         // invoke the 1 or 2-arg method 
191         if (twoArgAgent) {
192             m.invoke(null, new Object[] { optionsString, this });
193         } else {
194             m.invoke(null, new Object[] { optionsString });
195         }
<your code>
  xxxxx@xxxxx   2005-06-22  customer :12:48 GMT

<moved problem description here from comment note #1>

This code can cause a small issue.
if my agentclass has a super class or interfaces that has a two parameter method, then we will pick up a wrong path.
Some thing like this.
public class X {
   public static void premain/agentmain() // two parameter method.
}
public class Y extends X {
   public static void    premain/agentMain() // single parameter method.
}
if my manifest has
    Agent-Class: Y
then
Y.class.getMethod("premain",new Class[] {String.class, String.class}) --> X.premain(String, String);
Y.class.getDeclaredMethod("premain",new Class[] {String.class, String.class}) --> null;

We will start agent running from X, instead of Y, because we will get two parameter method from X first.
  xxxxx@xxxxx   2005-06-22  customer :12:48 GMT
Posted Date : 2008-02-16 02:43:21.0

The code is a little bit different in Dolphin-B24, but
the bug is still there.
Posted Date : 2008-02-16 01:24:38.0

The following two new tests will fail without this fix in
a promoted JDK:

    java/lang/instrument/PremainClass/InheritAgent1001.java
    java/lang/instrument/PremainClass/InheritAgent1101.java
Posted Date : 2008-02-21 06:08:16.0

N/A

The submitter is correct and goes back to the original JPLIS implementation. Unlikely to occur in practice but should be fixed.
  xxxxx@xxxxx   2005-06-22 03:20:45 GMT
The submitter is mostly right. We need to check:

    1) declared with a signature of (String, Instrumentation)
    2) declared with a signature of (String)
    3) inherited with a signature of (String, Instrumentation)
    4) inherited with a signature of (String)

The more important part of this bug is that we need some
tests for the various premain() combinations.
Posted Date : 2008-02-16 03:18:51.0