org.springframework.boot.availability.ApplicationAvailabilityBean Maven / Gradle / Ivy
/*
* Copyright 2012-2020 the original author or authors.
*
* 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
*
* https://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.springframework.boot.availability;
import java.util.HashMap;
import java.util.Map;
import org.springframework.context.ApplicationListener;
import org.springframework.util.Assert;
/**
* Bean that provides an {@link ApplicationAvailability} implementation by listening for
* {@link AvailabilityChangeEvent change events}.
*
* @author Brian Clozel
* @author Phillip Webb
* @since 2.3.0
* @see ApplicationAvailability
*/
public class ApplicationAvailabilityBean
implements ApplicationAvailability, ApplicationListener> {
private final Map, AvailabilityChangeEvent> events = new HashMap<>();
@Override
public S getState(Class stateType, S defaultState) {
Assert.notNull(stateType, "StateType must not be null");
Assert.notNull(defaultState, "DefaultState must not be null");
S state = getState(stateType);
return (state != null) ? state : defaultState;
}
@Override
public S getState(Class stateType) {
AvailabilityChangeEvent event = getLastChangeEvent(stateType);
return (event != null) ? event.getState() : null;
}
@Override
@SuppressWarnings("unchecked")
public AvailabilityChangeEvent getLastChangeEvent(Class stateType) {
return (AvailabilityChangeEvent) this.events.get(stateType);
}
@Override
public void onApplicationEvent(AvailabilityChangeEvent event) {
Class stateType = getStateType(event.getState());
this.events.put(stateType, event);
}
@SuppressWarnings("unchecked")
private Class getStateType(AvailabilityState state) {
if (state instanceof Enum) {
return (Class) ((Enum) state).getDeclaringClass();
}
return state.getClass();
}
}