001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.rest.server.health;
018
019import static java.util.EnumSet.*;
020
021import java.util.*;
022
023/**
024 * Functional SPI for reporting health of one component.
025 *
026 * @since 10.0.0
027 */
028@FunctionalInterface
029public interface HealthIndicator {
030
031   /**
032    * Performs the health check.
033    *
034    * @return Health result. Never <jk>null</jk>.
035    */
036   Health check();
037
038   /**
039    * Probe categories where this indicator should run.
040    *
041    * <p>
042    * Default is liveness + readiness.
043    *
044    * @return Probe categories. Never <jk>null</jk>.
045    */
046   default EnumSet<HealthProbe> probes() {
047      return of(HealthProbe.LIVE, HealthProbe.READY);
048   }
049}