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

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Here is the source code for org.eclipse.gyrex.common.console.SubCommand.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.util.Map;
import java.util.TreeMap;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.exception.ExceptionUtils;
import org.apache.commons.lang.text.StrBuilder;

/**
 * Base class for commands which contain other commands.
 */
public abstract class SubCommand extends Command {

    String parentCommandName;
    boolean printErrorDetails;

    final Map<String, Class<? extends Command>> commands = new TreeMap<String, Class<? extends Command>>();

    private final String name;

    /**
     * Creates a new instance.
     * 
     * @param name
     *            the command name, i.e. the name under which the sub command is
     *            registered with the provider/parent command and shall be
     *            invoked from the console
     */
    public SubCommand(final String name) {
        super("<cmd> [args]");
        this.name = name;
        if (StringUtils.isBlank(name)) {
            throw new IllegalArgumentException("command name must not be null");
        }
    }

    @Override
    protected final void doExecute() throws Exception {
        final String command = ci.nextArgument();
        if (StringUtils.isBlank(command)) {
            ci.println("ERROR: Missing command name!");
            ci.println(getHelp());
            return;
        } else if (CommandUtil.isHelpOption(command)) {
            ci.println(getHelp());
            return;
        }

        final Class<? extends Command> cmdClass = commands.get(command);
        if (cmdClass == null) {
            ci.println("ERROR: Command not found!");
            ci.println(getHelp());
            return;
        }

        CommandUtil.executeCommand(ci, cmdClass, command,
                null != parentCommandName ? String.format("%s %s", parentCommandName, getCommandName())
                        : getCommandName(),
                printErrorDetails);
    }

    /**
     * @return the command name
     */
    protected final String getCommandName() {
        return name;
    }

    /**
     * Answer a string (may be as many lines as you like) with help texts that
     * explain the command.
     * <p>
     * The default implementation returns a list of registered commands
     * including their descriptions).
     * </p>
     * 
     * @see org.eclipse.osgi.framework.console.CommandProvider#getHelp()
     */
    public String getHelp() {
        final StrBuilder help = new StrBuilder(512);
        if (null == parentCommandName) {
            help.append("---").append(getClass().getSimpleName()).appendln("---");
            help.append("\t").append(getCommandName()).appendln(" <cmd> [args]");
        } else {
            help.append("\t").append(parentCommandName).append(' ').append(getCommandName())
                    .appendln(" <cmd> [args]");
        }
        for (final String name : commands.keySet()) {
            try {
                help.append("\t\t").append(name);
                final Command command = commands.get(name).newInstance();
                //            final CmdLineParser parser = new CmdLineParser(command);
                final String description = command.getDescription();
                if (!StringUtils.contains(description, " - ")) {
                    help.append(" - ");
                } else if (!StringUtils.startsWith(description, " ")) {
                    help.append(' ');
                }
                help.appendln(description);
                //            help.append("\t\t\t");
                //            parser.printSingleLineUsage(help.asWriter(), null);
                //            help.appendNewLine();
            } catch (final Exception e) {
                help.append("\t\t").append(name).append(" - ").appendln(ExceptionUtils.getRootCauseMessage(e));
            }
        }
        return help.toString();
    }

    /**
     * Registers a sub-command
     * 
     * @param commandClass
     *            the command implementation class
     */
    protected final void registerCommand(final Class<? extends SubCommand> commandClass) {
        try {
            commands.put(commandClass.newInstance().getCommandName(), commandClass);
        } catch (final Exception e) {
            throw new IllegalStateException(String.format("Unable to register command class '%s'. %s",
                    commandClass.getSimpleName(), e.getMessage()), e);
        }
    }

    /**
     * Registers a sub command
     * 
     * @param name
     *            the command name
     * @param commandClass
     *            the command implementation class
     */
    protected final void registerCommand(final String name, final Class<? extends Command> commandClass) {
        commands.put(name, commandClass);
    }

    /**
     * Unregisters a sub command
     * 
     * @param name
     */
    protected final void unregisterCommand(final String name) {
        commands.remove(name);
    }

}