org.age.console.Console.java Source code

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Here is the source code for org.age.console.Console.java

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/*
 * Copyright (C) 2014 Intelligent Information Systems Group.
 *
 * This file is part of AgE.
 *
 * AgE 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.
 *
 * AgE 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 AgE.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.age.console;

import static java.util.Objects.isNull;

import org.age.console.command.Command;
import org.age.console.command.MainCommand;

import com.beust.jcommander.JCommander;
import com.beust.jcommander.ParameterException;
import com.google.common.collect.Iterables;

import jline.console.ConsoleReader;

import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Collection;
import java.util.regex.Pattern;

import javax.annotation.PostConstruct;
import javax.inject.Inject;

/**
 * Console is the shell-like interface for managing the cluster and AgE nodes.
 *
 * A command is a class that implements the {@link org.age.console.command.Command} interface
 * and is annotated using the {@link com.beust.jcommander.Parameters} and {@link javax.inject.Named} annotations.
 * Such commands are automatically recognized and available for the user.
 */
public final class Console {

    private static final Pattern WHITESPACE = Pattern.compile("\\s");

    private static final Logger log = LoggerFactory.getLogger(Console.class);

    private final ConsoleReader reader = new ConsoleReader();

    private final @MonotonicNonNull PrintWriter printWriter;

    @Inject
    private @MonotonicNonNull ApplicationContext applicationContext;

    @Inject
    private @MonotonicNonNull CommandCompleter commandCompleter;

    public Console() throws IOException {
        reader.setPrompt("AgE> ");

        printWriter = new PrintWriter(reader.getOutput());
    }

    @PostConstruct
    private void construct() {
        reader.addCompleter(commandCompleter);
    }

    public void mainLoop() throws IOException {
        String line;
        while ((line = reader.readLine()) != null) {
            log.debug("Read command: {}.", line);
            try {
                // We need to allocate new instances every time
                final MainCommand mainCommand = new MainCommand();
                final JCommander mainCommander = new JCommander(mainCommand);
                final Collection<Command> commands = applicationContext.getBeansOfType(Command.class).values();
                commands.forEach(mainCommander::addCommand);

                mainCommander.parse(WHITESPACE.split(line));
                final String parsedCommand = mainCommander.getParsedCommand();

                final Command command;
                final JCommander commander;
                if (isNull(parsedCommand)) {
                    commander = mainCommander;
                    command = mainCommand;
                } else {
                    commander = mainCommander.getCommands().get(parsedCommand);
                    command = (Command) Iterables.getOnlyElement(commander.getObjects());
                }
                if (!command.execute(commander, reader, printWriter)) {
                    break;
                }
            } catch (final ParameterException e) {
                log.error("Incorrect command.", e);
                printWriter.println("Incorrect command." + e.getMessage());
            }
        }
    }
}