Use context classLoader to load driver, if present. Fixes (swaldman#105)

src/java/com/mchange/v2/c3p0/DriverManagerDataSource.java

@@ -140,7 +140,16 @@ private synchronized void ensureDriverLoaded() throws SQLException
  if (! isDriverClassLoaded())
  {
  if (driverClass != null)
- Class.forName( driverClass );
+ {
+ Class driverCls = loadDriver(driverClass);
+ if(!driverCls.getClassLoader().equals(this.getClass().getClassLoader()))
+ {
+ logger.warning( "Driver '" + driverClass + "' was loaded with a classloader different than C3P0's. Forcing lookup by name sonce the DriverManager won't fin it from C3P0's classloader." );
+ logger.finest("Driver '" + driverClass + "' classloader: " + driverCls.getClassLoader().toString());
+ logger.finest("C3P0 classloader: " + this.getClass().getClassLoader().toString());
+ setForceUseNamedDriverClass(true);
+ }
+ }
  setDriverClassLoaded( true );
  }
  }
@@ -151,6 +160,25 @@ private synchronized void ensureDriverLoaded() throws SQLException
  }
  }
 
+ private Class loadDriver(String driverClass) throws ClassNotFoundException
+ {
+ try
+ {
+ return Class.forName(driverClass);
+ }
+ catch (ClassNotFoundException e)
+ {
+ if (Thread.currentThread().getContextClassLoader() != null)
+ {
+ return Class.forName(driverClass, true, Thread.currentThread().getContextClassLoader());
+ }
+ else
+ {
+ throw e;
+ }
+ }
+ }
+
  // should NOT be sync'ed -- driver() is sync'ed and that's enough
  // sync'ing the method creates the danger that one freeze on connect
  // blocks access to the entire DataSource
@@ -273,9 +301,9 @@ private synchronized Driver driver() throws SQLException
  logger.finer( "Circumventing DriverManager and instantiating driver class '" + driverClass + 
  "' directly. (forceUseNamedDriverClass = " + forceUseNamedDriverClass + ")" );
 
- try 
- { 
- driver = (Driver) Class.forName( driverClass ).newInstance();
+ try
+ {
+ driver = (Driver) loadDriver(driverClass).newInstance();
  this.setDriverClassLoaded( true );
  }
  catch (Exception e)