eagle-security/eagle-security-common/src/main/java/org/apache/eagle/security/util/JVMSingleQuartzScheduler.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.eagle.security.util;

import org.quartz.Scheduler;
import org.quartz.SchedulerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Quartz scheduler is created not thread safe, so a singleton has to be there if we want a JVM level single scheduler
 */
public class JVMSingleQuartzScheduler {
    private static final Logger LOG = LoggerFactory.getLogger(JVMSingleQuartzScheduler.class);

    private static JVMSingleQuartzScheduler instance = new JVMSingleQuartzScheduler();
    private Scheduler sched;

    public static JVMSingleQuartzScheduler getInstance() {
        return instance;
    }

    private JVMSingleQuartzScheduler() {
        try {
            SchedulerFactory schedFact = new org.quartz.impl.StdSchedulerFactory();
            sched = schedFact.getScheduler();
            sched.start();
        } catch (Exception ex) {
            LOG.error("Fail starting quartz scheduler", ex);
            throw new IllegalStateException(ex);
        }
    }

    public Scheduler getScheduler() {
        return sched;
    }
}