org.wildfly.swarm.spi.api.ClassLoading Maven / Gradle / Ivy
/**
* Copyright 2015-2017 Red Hat, Inc, and individual contributors.
*
* 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 org.wildfly.swarm.spi.api;
import java.util.concurrent.Callable;
/**
* Utility to execute code within a context using a particular {@code ClassLoader} as the
* thread-context-classloader.
*
* @apiNote Internal usage
*/
public interface ClassLoading {
/** With a given {@code ClassLoader}, execute an action with that classloader as the TCCL.
*
* This method will safely reset the TCCL for the duration of the action, while
* returning it to it's original value when the action completes, either successfully
* or exceptionally.
*
* @param loader The classloader.
* @param action The action to execute.
* @param The return type from the action.
* @return
*/
static T withTCCL(ClassLoader loader, Callable action) {
ClassLoader oldTCCL = Thread.currentThread().getContextClassLoader();
try {
Thread.currentThread().setContextClassLoader(loader);
return action.call();
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
Thread.currentThread().setContextClassLoader(oldTCCL);
}
}
}