/*
* Copyright 2016 Red Hat, Inc.
*
* 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.jboss.as.security.elytron;
import static org.wildfly.common.Assert.checkNotNullParam;
import org.jboss.msc.service.Service;
import org.jboss.msc.service.StartContext;
import org.jboss.msc.service.StartException;
import org.jboss.msc.service.StopContext;
/**
* A simple {@link Service} that relies on a {@link ValueSupplier} implementation to create an instance of the type that
* this service provides.
*
* @param <T> the type of value that this service provides; may be {@link Void}.
* @author <a href="mailto:sguilhen@redhat.com">Stefan Guilhen</a>
*/
class BasicService<T> implements Service<T> {
private ValueSupplier<T> valueSupplier;
private volatile T value;
BasicService() {
}
BasicService(ValueSupplier<T> valueSupplier) {
this.valueSupplier = checkNotNullParam("valueSupplier", valueSupplier);
}
void setValueSupplier(ValueSupplier<T> valueSupplier) {
this.valueSupplier = checkNotNullParam("valueSupplier", valueSupplier);
}
@Override
public void start(StartContext context) throws StartException {
value = checkNotNullParam("valueSupplier", valueSupplier).get();
}
@Override
public void stop(StopContext context) {
valueSupplier.dispose();
value = null;
}
@Override
public T getValue() throws IllegalStateException, IllegalArgumentException {
return value;
}
/**
* A supplier for the value returned by this service, the {@link #get()} methods allows for a {@link StartException} to be
* thrown so can be used with failed mandatory service injection.
*/
@FunctionalInterface
interface ValueSupplier<T> {
T get() throws StartException;
default void dispose() {}
}
}