ca.nines.ise.cmd.Command.java Source code

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Here is the source code for ca.nines.ise.cmd.Command.java

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/*
 * Copyright (C) 2014 Michael Joyce <ubermichael@gmail.com>
 *
 * 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 version 2.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package ca.nines.ise.cmd;

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import org.apache.commons.cli.BasicParser;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.SuffixFileFilter;
import org.apache.commons.io.filefilter.TrueFileFilter;
import org.atteo.classindex.IndexSubclasses;

/**
 * Superclass for all executable commands.
 *
 * @author Michael Joyce <ubermichael@gmail.com>
 */
@IndexSubclasses
abstract public class Command {

    /**
     * List of commands, which are subclasses of Command. Subclass indexing is
     * provided by ClassIndex.
     *
     * @see org.atteo.classindex.IndexSubclasses
     */
    protected static final HashMap<String, Class<? extends Command>> commandList = new HashMap<>();

    /**
     * Return a description of the command.
     *
     * @return String
     */
    abstract public String description();

    /**
     * Execute a command.
     *
     * @param cmd
     * @throws Exception
     */
    abstract public void execute(CommandLine cmd) throws Exception;

    /**
     * Parse the command line args[] array and return the result.
     *
     * @param opts
     * @param args
     * @return CommandLine
     * @throws ParseException
     */
    public CommandLine getCommandLine(Options opts, String[] args) throws ParseException {
        CommandLine cmd;
        CommandLineParser parser = new BasicParser();
        cmd = parser.parse(opts, args);
        return cmd;
    }

    /**
     * Get a list of file paths from the command line arguments.
     *
     * @param cmd
     * @return File[]
     */
    public File[] getFilePaths(CommandLine cmd) {
        Collection<File> fileList = new ArrayList<>();

        List<?> argList = cmd.getArgList();
        argList = argList.subList(1, argList.size());
        String[] args = argList.toArray(new String[argList.size()]);

        if (argList.isEmpty()) {
            File dir = new File("input");
            SuffixFileFilter sfx = new SuffixFileFilter(".txt");
            fileList = FileUtils.listFiles(dir, sfx, TrueFileFilter.INSTANCE);
        } else {
            for (String name : args) {
                fileList.add(new File(name));
            }
        }

        File[] files = fileList.toArray(new File[fileList.size()]);
        Arrays.sort(files);
        return files;
    }

    /**
     * Get a list of arguments for the command.
     *
     * @param cmd
     * @return String[]
     */
    public String[] getArgList(CommandLine cmd) {
        List<?> argList = cmd.getArgList();
        argList = argList.subList(1, argList.size());
        String[] args = argList.toArray(new String[argList.size()]);
        return args;
    }

    /**
     * Turn the description and arguments list into nicely formatted help and
     * usage documentation.
     */
    public void help() {
        HelpFormatter formatter = new HelpFormatter();
        Options opts = getOptions();
        System.out.println(description());
        if (opts.getOptions().size() > 0) {
            formatter.printHelp(this.getClass().getSimpleName().toLowerCase() + " " + getUsage(), opts);
        } else {
            System.out.println(this.getClass().getSimpleName().toLowerCase() + " " + getUsage());
        }
    }

    /**
     * Generates the Options for the command.
     *
     * @return Options
     */
    public abstract Options getOptions();

    /**
     * Generate a brief usage of the command.
     *
     * @return String
     */
    public String getUsage() {
        return "[options] [files]";
    }
}