DynamicRouteDeployer.java

/**
 * Copyright (c) Codice Foundation
 * <p/>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p/>
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package org.codice.ddf.broker.route.manager;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.camel.CamelContext;
import org.apache.camel.model.RouteDefinition;
import org.apache.felix.fileinstall.ArtifactInstaller;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Bundle that monitors for camel routes defined in xml files placed in <DDF_HOME>/etc/routes and
 * then loads them into the camelContext
 */
public class DynamicRouteDeployer implements ArtifactInstaller {
    private static final Logger LOGGER = LoggerFactory.getLogger(DynamicRouteDeployer.class);

    private final CamelContext camelContext;

    private Map<File, List<RouteDefinition>> processedFiles = new HashMap<>();

    public DynamicRouteDeployer(CamelContext camelContext) {
        this.camelContext = camelContext;
    }

    public void init() {

    }

    public void destroy() throws Exception {
        camelContext.stop();
    }

    @Override
    public void install(File file) throws Exception {
        try (InputStream is = new FileInputStream(file)) {
            List<RouteDefinition> routeDefinitions;

            LOGGER.info("Loading route path: {}", file.getName());

            routeDefinitions = camelContext.loadRoutesDefinition(is)
                    .getRoutes();

            camelContext.addRouteDefinitions(routeDefinitions);
            processedFiles.put(file, routeDefinitions);
            camelContext.startAllRoutes();

        } catch (Exception e) {
            LOGGER.warn("Failed to read route definition. See debug log for stack trace.");
            LOGGER.debug(e.getMessage(), e);
        }
    }

    @Override
    public void update(File file) throws Exception {
        uninstall(file);
        install(file);
    }

    @Override
    public void uninstall(File file) throws Exception {
        LOGGER.info("Removing route path: {}", file.getName());
        try {
            camelContext.removeRouteDefinitions(processedFiles.get(file));
        } catch (Exception e) {
            LOGGER.warn("Failed to remove routes definition. See debug log for stack trace.");
            LOGGER.debug(e.getMessage(), e);
        }
        processedFiles.remove(file);
    }

    @Override
    public boolean canHandle(File file) {
        return file.getName()
                .endsWith(".xml");
    }

}