org.springframework.integration.leader.Context.java Source code

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Here is the source code for org.springframework.integration.leader.Context.java

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/*
 * 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.
 * <p>
 * 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;
    }

}