storm-server/src/main/java/org/apache/storm/utils/StormCommonInstaller.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.storm.utils;

import org.apache.storm.daemon.StormCommon;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/*
 * Just for testing purpose. After the migration of testing.clj. This class could be removed.
 */
public class StormCommonInstaller implements AutoCloseable {
    private static final Logger LOG = LoggerFactory.getLogger(StormCommonInstaller.class);
    private StormCommon _oldInstance;
    private StormCommon _curInstance;

    public StormCommonInstaller(StormCommon instance) {
        _oldInstance = StormCommon.setInstance(instance);
        _curInstance = instance;
    }

    @Override
    public void close() throws Exception {
        if (StormCommon.setInstance(_oldInstance) != _curInstance) {
            throw new IllegalStateException(
                "Instances of this resource must be closed in reverse order of opening.");
        }
    }
}