/* ServiceWrapperChain.java
*
* Copyright 2009-2012 Comcast Interactive Media, LLC.
*
* 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.fishwife.jrugged;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
public class ServiceWrapperChain implements ServiceWrapper {
private final List<ServiceWrapper> wrappers;
public ServiceWrapperChain(final Collection<ServiceWrapper> wrappers) {
final ArrayList<ServiceWrapper> rev = new ArrayList<>();
for (final ServiceWrapper wrapper : wrappers) {
rev.add(0, wrapper);
}
this.wrappers = rev;
}
private <T> Callable<T> wrap(final Callable<T> c, final ServiceWrapper wrapper) {
return new Callable<T>() {
@Override
public T call() throws Exception {
return wrapper.invoke(c);
}
};
}
private Runnable wrap(final Runnable r, final ServiceWrapper wrapper) {
return new Runnable() {
@Override
public void run() {
try {
wrapper.invoke(r);
} catch (final Exception e) {
throw new RuntimeException(e);
}
}
};
}
@Override
public <T> T invoke(final Callable<T> c) throws Exception {
Callable<T> c2 = c;
for (final ServiceWrapper wrapper : wrappers) {
c2 = wrap(c2, wrapper);
}
return c2.call();
}
@Override
public void invoke(final Runnable r) throws Exception {
Runnable r2 = r;
for (final ServiceWrapper wrapper : wrappers) {
r2 = wrap(r2, wrapper);
}
r2.run();
}
@Override
public <T> T invoke(final Runnable r, final T result) throws Exception {
invoke(r);
return result;
}
}