li.strolch.runtime.main.MainStarter.java Source code

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Here is the source code for li.strolch.runtime.main.MainStarter.java

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/*
 * Copyright 2013 Robert von Burg <eitch@eitchnet.ch>
 * 
 * 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 li.strolch.runtime.main;

import java.io.File;
import java.io.InputStream;
import java.text.MessageFormat;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import li.strolch.agent.api.StrolchAgent;
import li.strolch.agent.api.StrolchBootstrapper;
import li.strolch.agent.api.StrolchVersion;
import li.strolch.utils.dbc.DBC;
import li.strolch.utils.helper.StringHelper;

/**
 * @author Robert von Burg <eitch@eitchnet.ch>
 */
@SuppressWarnings("nls")
public class MainStarter {

    private static final Logger logger = LoggerFactory.getLogger(MainStarter.class);

    private static final String OPT_ROOT_PATH = "root-path";
    private static final String OPT_ENV = "env";

    private Options options;
    private String env;
    private File pathF;

    private StrolchAgent agent;

    private StrolchVersion appVersion;

    /**
     * @param appVersion
     *            See {@link StrolchBootstrapper#StrolchBootstrapper(StrolchVersion)}
     */
    public MainStarter(StrolchVersion appVersion) {
        DBC.PRE.assertNotNull("appVersion must be set!", appVersion);
        this.appVersion = appVersion;

        configureOptions();
    }

    /**
     * @param appClass
     *            See {@link StrolchBootstrapper#StrolchBootstrapper(Class)}
     */
    public MainStarter(Class<?> appClass) {
        DBC.PRE.assertNotNull("appClass must be set!", appClass);

        Properties env = new Properties();
        try (InputStream in = appClass.getResourceAsStream(StrolchBootstrapper.APP_VERSION_PROPERTIES)) {
            env.load(in);
        } catch (Exception e) {
            throw new IllegalArgumentException("Could not find resource "
                    + StrolchBootstrapper.APP_VERSION_PROPERTIES + " on ClassLoader of class " + appClass);
        }

        StrolchVersion appVersion = new StrolchVersion(env);
        this.appVersion = appVersion;

        configureOptions();
    }

    private void configureOptions() {

        Options op = new Options();
        Option rootPathOption = new Option("p", OPT_ROOT_PATH, true, "root path to strolch runtime");
        rootPathOption.setOptionalArg(false);
        rootPathOption.setRequired(true);
        op.addOption(rootPathOption);

        Option envOption = new Option("e", OPT_ENV, true, "environment to load from configuration file");
        envOption.setOptionalArg(false);
        envOption.setRequired(true);
        op.addOption(envOption);

        this.options = op;
    }

    public int start(String[] args) {
        int ret = parseArgs(args);
        if (ret != 0)
            return ret;

        setup();
        initialize();
        start();

        return keepAlive();
    }

    public int parseArgs(String[] args) {

        // create the parser
        CommandLineParser parser = new GnuParser();
        CommandLine line;
        try {
            // parse the command line arguments
            line = parser.parse(this.options, args);
        } catch (ParseException exp) {
            // oops, something went wrong
            logger.error("Parsing failed.  Reason: " + exp.getMessage());
            printUsage();
            return 1;
        }

        this.env = line.getOptionValue(OPT_ENV);
        if (StringHelper.isEmpty(this.env)) {
            logger.error("env argument is missing!");
            printUsage();
            return 1;
        }

        String pathS = line.getOptionValue(OPT_ROOT_PATH);
        this.pathF = new File(pathS);
        if (!this.pathF.exists()) {
            logger.error(MessageFormat.format("Path parameter does not exist at: {0}", pathS));
            printUsage();
            return 1;
        }

        return 0;
    }

    public void setup() {
        this.agent = new StrolchBootstrapper(this.appVersion).setupByRoot(this.env, this.pathF);
    }

    public void initialize() {
        getAgent().initialize();
    }

    public void start() {
        getAgent().start();
    }

    public void stop() {
        getAgent().stop();
    }

    public void destroy() {
        getAgent().destroy();
    }

    public int keepAlive() {

        final AtomicBoolean atomicBoolean = new AtomicBoolean();

        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                synchronized (MainStarter.class) {
                    System.out.println("VM Shutting down. Stopping Strolch...");
                    System.out.println("");
                    System.out.println("Strolch application " + MainStarter.this.getAgent().getApplicationName()
                            + " shutting down...");
                    MainStarter.this.getAgent().stop();
                    MainStarter.this.getAgent().destroy();
                    System.out.println("Strolch application " + MainStarter.this.getAgent().getApplicationName()
                            + " shut down. Exiting VM.");

                    atomicBoolean.set(true);
                    MainStarter.class.notify();
                }
            }
        });

        logger.info("");
        logger.info("Strolch application " + getAgent().getApplicationName() + " started ");
        while (!atomicBoolean.get()) {
            synchronized (MainStarter.class) {
                try {
                    MainStarter.class.wait();
                } catch (InterruptedException e) {
                    logger.error("Interrupted.");
                    return 1;
                }
            }
        }

        return 0;
    }

    private void printUsage() {
        HelpFormatter formatter = new HelpFormatter();
        formatter.printHelp("java -classpath lib/ -jar <jar.containing.main.class>.jar <options>", this.options);
    }

    public StrolchAgent getAgent() {
        return this.agent;
    }
}