From f67735a77e41ba52ddcc79d48c9435152e46b1e1 Mon Sep 17 00:00:00 2001
From: Rodro <rodrigo.merino@mulesoft.com>
Date: Thu, 5 Apr 2018 15:33:18 -0300
Subject: [PATCH] Use context classLoader to load driver, if present. Fixes
 (#105)

---
 .../v2/c3p0/DriverManagerDataSource.java      | 36 ++++++++++++++++---
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/src/java/com/mchange/v2/c3p0/DriverManagerDataSource.java b/src/java/com/mchange/v2/c3p0/DriverManagerDataSource.java
index 6274d6f6..efded774 100644
--- a/src/java/com/mchange/v2/c3p0/DriverManagerDataSource.java
+++ b/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)