org.springframework.integration.leader.Context Maven / Gradle / Ivy
/*
* Copyright 2014-2019 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.integration.leader;
import org.springframework.lang.Nullable;
/**
* Interface that defines the context for candidate leadership.
* Instances of this object are passed to {@link Candidate candidates}
* upon granting and revoking of leadership.
*
* The {@link Context} is {@link FunctionalInterface}
* with no-op implementation for the {@link #yield()}.
*
* @author Patrick Peralta
* @author Janne Valkealahti
* @author Artem Bilan
* @author Gary Russell
*
*/
@FunctionalInterface
public interface Context {
/**
* Checks if the {@link Candidate} this context was
* passed to is the leader.
* @return true if the {@link Candidate} this context was
* passed to is the leader
*/
boolean isLeader();
/**
* Causes the {@link Candidate} this context was passed to
* to relinquish leadership. This method has no effect
* if the candidate is not currently the leader.
*/
default void yield() {
// no-op
}
/**
* Get the role for the {@link Candidate}.
* @return the role.
* @since 5.0.6
*/
@Nullable
default String getRole() {
return null;
}
}