org.apache.tomcat.jdbc.pool.ClassLoaderUtil Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tomcat.jdbc.pool;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
public class ClassLoaderUtil {
private static final Log log = LogFactory.getLog(ClassLoaderUtil.class);
private static final boolean onlyAttemptFirstLoader =
Boolean.getBoolean("org.apache.tomcat.jdbc.pool.onlyAttemptCurrentClassLoader");
public static Class loadClass(String className, ClassLoader... classLoaders) throws ClassNotFoundException {
ClassNotFoundException last = null;
StringBuilder errorMsg = null;
for (ClassLoader cl : classLoaders) {
try {
if (cl!=null) {
if (log.isDebugEnabled()) {
log.debug("Attempting to load class["+className+"] from "+cl);
}
return Class.forName(className, true, cl);
} else {
throw new ClassNotFoundException("Classloader is null");
}
} catch (ClassNotFoundException x) {
last = x;
if (errorMsg==null) {
errorMsg = new StringBuilder();
} else {
errorMsg.append(';');
}
errorMsg.append("ClassLoader:");
errorMsg.append(cl);
}
if (onlyAttemptFirstLoader) {
break;
}
}
throw new ClassNotFoundException("Unable to load class: "+className+" from "+errorMsg, last);
}
}