/*
* JBoss, Home of Professional Open Source.
* Copyright 2015, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.wildfly.extension.batch.jberet.deployment;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Collection;
import java.util.Deque;
/**
* Allows a handle to setup any thread local context needed.
*
* @author <a href="mailto:jperkins@redhat.com">James R. Perkins</a>
*/
interface ContextHandle {
/**
* Sets up any thread local context.
*
* @return a handle to tear down the thread local context when the invocation has finished
*/
Handle setup();
/**
* Handles tearing down the thread local context.
*/
interface Handle {
/**
* Tears down the thread local context.
*/
void tearDown();
}
/**
* A handle that processes {@link ContextHandle context handles} in the order in which they are added. The {@link
* ContextHandle.Handle#tearDown()} is processed in the reverse order that the {@link
* ContextHandle context handles} are processed.
* <p/>
* If a {@link ContextHandle context handle} throws an exception the {@link ContextHandle.Handle#tearDown()
* tear downs} will be processed.
* <p/>
* If an exception is thrown during the {@link ContextHandle.Handle#tearDown() tear
* down} the remaining tear downs will be processed and only the initial exception will be re-thrown.
*/
class ChainedContextHandle implements ContextHandle {
private final Collection<ContextHandle> contextHandles;
public ChainedContextHandle(final ContextHandle... contextHandles) {
this.contextHandles = Arrays.asList(contextHandles);
}
@Override
public Handle setup() {
final Deque<Handle> handles = new ArrayDeque<>();
try {
for (ContextHandle contextHandle : contextHandles) {
// reverse order
handles.addFirst(contextHandle.setup());
}
return new Handle() {
@Override
public void tearDown() {
Exception rethrow = null;
for (Handle handle : handles) {
try {
handle.tearDown();
} catch (Exception e) {
if (rethrow == null) rethrow = e;
}
}
if (rethrow != null) {
throw new RuntimeException(rethrow);
}
}
};
} catch (Exception e) {
for (Handle handle : handles) {
try {
handle.tearDown();
} catch (Exception ignore) {
}
}
throw e;
}
}
}
}