com.prototype.utils.IndexChangeMonitorUtil.java Source code

Introduction

Here is the source code for com.prototype.utils.IndexChangeMonitorUtil.java

Source

package com.prototype.utils;

import java.io.File;

import org.apache.commons.io.monitor.FileAlterationMonitor;
import org.apache.commons.io.monitor.FileAlterationObserver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.prototype.client.StompMessageClient;
import com.prototype.utils.AppConstants;

/*
 * Copyright 2014 the original author or authors.
 *
 * 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.
 */

/**
 * 
 * @author mweigel
 *
 *         The IndexChangeMonitorUtil is a utility class for Monitor FileA
 *         lterations
 */
public class IndexChangeMonitorUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(IndexChangeMonitorUtil.class);

    /**
     * The indexing monitoring thread
     * 
     * @param client
     *            StompMessageClient used for routing messages to a subscribed
     *            endpoint
     * 
     * @throws Exception
     */
    public static FileAlterationMonitor monitorSolr(StompMessageClient client) throws Exception {
        File directory = new File(AppConstants.INDEX_FOLDER);

        // Create an instance of a FileAlterationObserver that is given a
        // SolrIndexFileFilter.
        FileAlterationObserver observer = new FileAlterationObserver(directory, new SolrIndexFileFilter());

        // Add a IndexChangeListenerImpl that has a reference to an instance of
        // a StompMessageClient. The listener is invoked when an index change event happens, 
        // and uses StompMessageClient to send a message to a Websocket topic endpoint.
        observer.addListener(new IndexChangeListenerImpl(client));

        FileAlterationMonitor monitor = new FileAlterationMonitor(AppConstants.POLL_INTERVAL);

        // The FileAlterationObserver will observe file alterations and then
        // invoke the IndexChangeListenerImpl
        monitor.addObserver(observer);

        // Start the FileAlterationMonitor thread
        monitor.start();

        LOGGER.info("monitorSolr() The FileAlterationMonitor thread was started");

        return monitor;
    }
}