samza-rest/src/main/java/org/apache/samza/monitor/MonitorLoader.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.samza.monitor;

import org.apache.samza.metrics.MetricsRegistry;
import org.apache.samza.util.ReflectionUtil;


/**
 * Helper class that instantiates the Monitor.
 */
public class MonitorLoader {

  public static Monitor instantiateMonitor(String monitorName, MonitorConfig monitorConfig,
      MetricsRegistry metricsRegistry) throws InstantiationException {
    String factoryClass = monitorConfig.getMonitorFactoryClass();
    try {
      MonitorFactory monitorFactory = ReflectionUtil.getObj(factoryClass, MonitorFactory.class);
      return monitorFactory.getMonitorInstance(monitorName, monitorConfig, metricsRegistry);
    } catch (Exception e) {
      throw (InstantiationException)
          new InstantiationException("Unable to instantiate monitor with factory class " + factoryClass).initCause(e);
    }
  }
}