org.eclipse.gyrex.common.console.CommandUtil.java Source code

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Here is the source code for org.eclipse.gyrex.common.console.CommandUtil.java

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/*******************************************************************************
 * Copyright (c) 2011, 2012 AGETO Service GmbH and others.
 * All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 *
 * Contributors:
 *     Gunnar Wagenknecht - initial API and implementation
 *******************************************************************************/
package org.eclipse.gyrex.common.console;

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.eclipse.osgi.framework.console.CommandInterpreter;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.SystemUtils;
import org.apache.commons.lang.exception.ExceptionUtils;
import org.apache.commons.lang.text.StrBuilder;
import org.kohsuke.args4j.CmdLineException;
import org.kohsuke.args4j.CmdLineParser;

/**
 * Utility for working with commands
 */
class CommandUtil {

    static void appendCommandDescription(final StrBuilder help, final String name, final Command command,
            final String ident) {
        help.append(ident).append(name);
        final String description = command.getDescription();
        if (!StringUtils.contains(description, " - ")) {
            help.append(" - ");
        } else if (!StringUtils.startsWith(description, " ")) {
            help.append(' ');
        }
        help.appendln(description);
    }

    static void appendCommandInfo(final StrBuilder help, final String commandName,
            final Map<String, Class<? extends Command>> commands, String ident) {
        help.append(ident).append(commandName).appendln(" <cmd> [args]");
        ident += "\t";
        for (final String name : commands.keySet()) {
            try {
                final Command command = commands.get(name).newInstance();
                if (command instanceof SubCommand) {
                    appendCommandInfo(help, name, ((SubCommand) command).commands, ident);
                } else {
                    appendCommandDescription(help, name, command, ident);
                }
            } catch (final Exception e) {
                help.append(ident).append(name).append(" - ").appendln(ExceptionUtils.getRootCauseMessage(e));
            }
        }
    }

    static void executeCommand(final CommandInterpreter ci, final Class<? extends Command> cmdClass,
            final String command, final String parentCommandName, final boolean printErrorDetails) {
        Command cmd;
        try {
            cmd = cmdClass.newInstance();
        } catch (final Exception e) {
            ci.println("ERROR: " + ExceptionUtils.getRootCauseMessage(e));
            return;
        }

        // check for sub-command
        if (cmd instanceof SubCommand) {
            // sub-command usually don't have arguments, thus we don't consume the CI for them
            ((SubCommand) cmd).printErrorDetails = printErrorDetails;
            ((SubCommand) cmd).parentCommandName = parentCommandName;
        } else {
            // parse commands using ARG4J
            boolean printHelp = false;
            final List<String> args = new ArrayList<String>();
            for (String arg = ci.nextArgument(); arg != null; arg = ci.nextArgument()) {
                if (isHelpOption(arg)) {
                    printHelp = true;
                    break;
                }
                args.add(arg);
            }

            final CmdLineParser parser = new CmdLineParser(cmd);
            if (printHelp) {
                printCommandHelp(ci, parentCommandName, command, parser);
                return;
            }

            try {
                parser.parseArgument(args.toArray(new String[args.size()]));
            } catch (final CmdLineException e) {
                ci.println("ERROR: " + e.getMessage());
                printCommandHelp(ci, parentCommandName, command, parser);
                return;
            }
        }

        // execute command
        try {
            cmd.execute(ci);
        } catch (final Exception e) {
            ci.println("ERROR: " + ExceptionUtils.getRootCauseMessage(e));
            if (printErrorDetails) {
                ci.printStackTrace(e);
            }
        }
    }

    static boolean isHelpOption(final String arg) {
        return StringUtils.equals("-h", arg) || StringUtils.equals("--help", arg);
    }

    static void printCommandHelp(final CommandInterpreter ci, final String name, final String command,
            final CmdLineParser parser) {
        final StringWriter stringWriter = new StringWriter();
        stringWriter.append(String.format("%s %s", name, command));
        parser.printSingleLineUsage(stringWriter, null);
        stringWriter.append(SystemUtils.LINE_SEPARATOR);
        parser.printUsage(stringWriter, null);
        stringWriter.flush();
        ci.println(stringWriter.toString());
    }

    private CommandUtil() {
        // empty
    }
}