lcsim/src/org/lcsim/job

diff -u -r1.15 -r1.16
--- JobControlManager.java	4 Feb 2009 00:20:33 -0000	1.15
+++ JobControlManager.java	11 Mar 2009 19:05:04 -0000	1.16
@@ -4,6 +4,7 @@

 import hep.physics.vec.Hep3Vector;
 
 import java.beans.BeanInfo;

+import java.beans.IntrospectionException;

 import java.beans.MethodDescriptor;
 import java.io.BufferedReader;
 import java.io.File;

@@ -771,27 +772,51 @@

 				type = availableDrivers.get(type);
 			}
 

+			//
+			// Get Class, BeanInfo, and Constructor, and setup the new Driver instance.
+			//
+			

 			// Class of the Driver.
 			Class driverClass;

-

+			try 
+			{
+				driverClass = loader.loadClass(type);
+			}
+			catch (ClassNotFoundException x)
+			{
+				throw new RuntimeException("The Driver class " + type + " could not be created."+  
+						" Check that the name and package is correct in your xml file.",x);
+			}
+			
+			if (printDriversDetailed)
+				logStream.println(driverClass.getCanonicalName());
+			

 			// BeanInfo for the Driver class.
 			BeanInfo beaninfo;

-

+			try 
+			{
+				beaninfo = java.beans.Introspector.getBeanInfo(driverClass);
+			}
+			catch (IntrospectionException x)
+			{
+				throw new RuntimeException("Problem loading a BeanInfo object for Driver class " + type + ".");
+			}
+			

 			// The Driver instance.
 			Driver newDriver;

-
-			// Get Class, BeanInfo, and Constructor, and setup the new Driver instance.
-			try

+			try 

 			{

-				driverClass = loader.loadClass(type);
-				if (printDriversDetailed)
-					logStream.println(driverClass.getCanonicalName());
-				beaninfo = java.beans.Introspector.getBeanInfo(driverClass);

 				newDriver = (Driver) driverClass.newInstance();

-			} 
-			catch (Exception x)

+			}
+			catch (InstantiationException x)

 			{

-				throw new RuntimeException(x);

+				throw new RuntimeException("Failed to create a Driver of class " + type + "." +
+						"This class might be missing a public constructor with no arguments.",x);
+			}
+			catch (IllegalAccessException x)
+			{
+				throw new RuntimeException("Cannot access Driver type " + type + "."+
+						"You may need to make this class or its constructor public.",x);

 			}
 
 			// Get a list of Driver parameters.