edu.emory.cci.aiw.neo4jetl.Neo4jHome.java Source code

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Here is the source code for edu.emory.cci.aiw.neo4jetl.Neo4jHome.java

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package edu.emory.cci.aiw.neo4jetl;

/*
 * #%L
 * AIW Neo4j ETL
 * %%
 * Copyright (C) 2015 Emory University
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import org.apache.commons.exec.CommandLine;
import org.apache.commons.exec.DefaultExecuteResultHandler;
import org.apache.commons.exec.DefaultExecutor;
import org.apache.commons.exec.ExecuteException;
import org.apache.commons.exec.ExecuteWatchdog;
import org.apache.commons.exec.Executor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 * @author Andrew Post
 */
class Neo4jHome {
    private static final Logger LOGGER = LoggerFactory.getLogger(Neo4jHome.class);
    private static final String SERVER_PROPERTIES = new File("conf", "neo4j-server.properties").getPath();
    private static final String SERVER_CONTROL_COMMAND = new File("bin", "neo4j").getPath();
    private final String home;
    private final File dbPath;

    Neo4jHome(String home) throws IOException {
        assert home != null : "home cannot be null";
        this.home = home;
        Properties serverProperties = new Properties();
        try (FileReader bf = new FileReader(new File(home, SERVER_PROPERTIES))) {
            serverProperties.load(bf);
        }
        this.dbPath = new File(home, serverProperties.getProperty("org.neo4j.server.database.location"));
    }

    File getDbPath() {
        return this.dbPath;
    }

    void startServer() throws IOException, InterruptedException, CommandFailedException {
        controlServer("start");
    }

    void stopServer() throws IOException, InterruptedException, CommandFailedException {
        controlServer("stop");
    }

    private void controlServer(String command) throws IOException, InterruptedException, CommandFailedException {
        LOGGER.debug("Executing neo4j command {}...", command);
        CommandLine serverControlCommand = new CommandLine(new File(this.home, SERVER_CONTROL_COMMAND));
        serverControlCommand.addArgument("${command}");
        Map<String, String> map = new HashMap<>();
        map.put("command", command);
        serverControlCommand.setSubstitutionMap(map);

        DefaultExecuteResultHandler resultHandler = new DefaultExecuteResultHandler();

        ExecuteWatchdog watchdog = new ExecuteWatchdog(60 * 1000);
        Executor executor = new DefaultExecutor();
        executor.setExitValue(1);
        executor.setWatchdog(watchdog);
        executor.execute(serverControlCommand, resultHandler);
        LOGGER.debug("Neo4j command {} is completed, checking exit value...", command);
        resultHandler.waitFor();
        int exitValue = resultHandler.getExitValue();
        if (exitValue != 0) {
            ExecuteException exception = resultHandler.getException();
            throw new CommandFailedException(exitValue, "Neo4j command '" + command + "' failed", exception);
        }
        LOGGER.debug("Neo4j command {} was successful", command);
    }

}