driverClassName = "com.mysql.jdbc.Driver" try { Class.forName(driverClassName) } catch (ClassNotFoundException e) { println("not found by Class.forName") try { Thread.currentThread().getContextClassLoader().loadClass(driverClassName); } catch (ClassNotFoundException e2) { println("not found by context class loader") // now lets try the classloader which loaded us try { groovy.sql.Sql.class.getClassLoader().loadClass(driverClassName); } catch (ClassNotFoundException e3) { println("not found by Sql.class.getClassLoader") } } } println("current thread context classloader: " + Thread.currentThread().getContextClassLoader()) loader = project.class.getClassLoader() println("project classloader : " + loader) loader = this.class.getClassLoader() while(loader != null) { try { c = loader.findClass("com.mysql.jdbc.Driver") println("found by " + loader.toString()) } catch(Throwable t) {println("not found by " + loader.toString())} loader = loader.getParent() }