scriptella.core.DriverFactory Maven / Gradle / Ivy
/*
* Copyright 2006-2012 The Scriptella Project Team.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package scriptella.core;
import scriptella.jdbc.GenericDriver;
import scriptella.spi.ScriptellaDriver;
import java.sql.Driver;
/**
* Factory for Scriptella Service Providers and JDBC drivers.
*
* @author Fyodor Kupolov
* @version 1.0
*/
public final class DriverFactory {
//singleton
private DriverFactory() {
}
/**
* Loads a driver specified by a full or a short name.
* This method tries to lookup a driver class specified by a name.
* The looking up procedure is the following:
*
* - Class with name
driverName is looked up.
* - If class not found, a class with the following name is checked:
* scriptella.driver.<driverName>.Driver
*
- If no classes found - an exception is raised.
*
*
* @param driverName driver class short or full name.
* @param loader class loader to use when loading driver classes.
* @return found driver class.
* @throws ClassNotFoundException if no drivers satisfy specified name.
*/
public static ScriptellaDriver getDriver(String driverName, ClassLoader loader) throws ClassNotFoundException {
//try direct match
try {
return getDriver(Class.forName(driverName, true, loader));
} catch (ClassNotFoundException e) {
//if not found try to produce a full name from a short one
String fullName = "scriptella.driver."+driverName+".Driver";
try {
return getDriver(Class.forName(fullName, true, loader));
} catch (ClassNotFoundException ignoredException) {
throw e;//it's not a typo - return the first exception
}
}
}
/**
* Creates a Scriptella Driver using specified class.
*
If class is a {@link Driver} {@link GenericDriver JDBC Bridge} is used.
*
To be successfully instantiated the driver class must implement {@link ScriptellaDriver} class
* and has no-arg public constructor.
*
* @param drvClass driver class.
* @return Scriptella Driver
*/
@SuppressWarnings("unchecked")
public static ScriptellaDriver getDriver(Class drvClass) {
if (Driver.class.isAssignableFrom(drvClass)) {
//We must load JDBC driver using the same classloader as drvClass
try {
ClassLoader drvClassLoader = drvClass.getClassLoader();
if (drvClassLoader==null) { //if boot classloader is used,
// load scriptella driver using the class loader for this class.
drvClassLoader=DriverFactory.class.getClassLoader();
}
Class cl = Class.forName("scriptella.jdbc.GenericDriver", true, drvClassLoader);
return (ScriptellaDriver)cl.newInstance();
} catch (Exception e) {
throw new IllegalStateException("Unable to instantiate JDBC driver for " + drvClass, e);
}
} else if (ScriptellaDriver.class.isAssignableFrom(drvClass)) {
try {
return (ScriptellaDriver) drvClass.newInstance();
} catch (Exception e) {
throw new IllegalStateException("Unable to instantiate driver for " + drvClass, e);
}
} else {
throw new IllegalArgumentException("Class " + drvClass + " is not a scriptella compatible driver.");
}
}
}