# YammerMetricsAssembler.java

    /*
     * Copyright (c) 2012, Niclas Hedhman. All Rights Reserved.
     *
     * 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
     *     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.qi4j.metrics.yammer;

    import com.yammer.metrics.Metrics;
    import com.yammer.metrics.reporting.AbstractPollingReporter;
    import com.yammer.metrics.reporting.ConsoleReporter;
    import com.yammer.metrics.reporting.CsvReporter;
    import java.io.File;
    import java.io.PrintStream;
    import java.util.concurrent.TimeUnit;
    import org.qi4j.api.common.Visibility;
    import org.qi4j.bootstrap.Assembler;
    import org.qi4j.bootstrap.AssemblyException;
    import org.qi4j.bootstrap.ModuleAssembly;

    public class YammerMetricsAssembler
        implements Assembler
    {

        private AbstractPollingReporter reporter;

        /**
         * Default constructor only creates a Yammer JMXReporter
         */
        public YammerMetricsAssembler()
        {
        }

        /**
         * Creates a ConsoleReporter and sends the output to the given PrintStream.
         *
         * @param out      The PrintStream to receive the output.
         * @param period   The reporting interval.
         * @param timeunit The TimeUnit for the reporting interval.
         */
        public YammerMetricsAssembler( PrintStream out, long period, TimeUnit timeunit )
        {
            reporter = new ConsoleReporter( out );
            try
            {
                reporter.start( period, timeunit );
            }
            catch( RuntimeException e )
            {
                e.printStackTrace();
                throw e;
            }
        }

        /**
         * Creates a CSV reporter and writes the result to the given directory
         *
         * @param outDirectory The directory to write the result to.
         * @param period       The reporting interval.
         * @param timeunit     The TimeUnit for the reporting interval.
         */
        public YammerMetricsAssembler( File outDirectory, long period, TimeUnit timeunit )
        {
            reporter = new CsvReporter( Metrics.defaultRegistry(), outDirectory );
            reporter.start( period, timeunit );
        }

        @Override
        public void assemble( ModuleAssembly module )
            throws AssemblyException
        {
            module.services( YammerMetricsProvider.class )
                .instantiateOnStartup()
                .visibleIn( Visibility.application );
        }

        /**
         * Closing any Reporter that has been started.
         */
        public void shutdown()
        {
            reporter.shutdown();
        }
    }