Groovy example source code file (RegisterCommand.groovy)

This example Groovy source code file (RegisterCommand.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

can, class, command, command, commandsupport, created, object, object, registercommand, registercommand, shell, string, todo, todo

The Groovy RegisterCommand.groovy source code

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.codehaus.groovy.tools.shell.commands

import org.codehaus.groovy.tools.shell.CommandSupport
import org.codehaus.groovy.tools.shell.Shell
import org.codehaus.groovy.tools.shell.Command

/**
 * The 'register' command.
 *
 * @version $Id: RegisterCommand.groovy 12257 2008-05-04 08:51:41Z user57 $
 * @author <a href="mailto:chris@wensel.net">Chris K Wensel
 */
class RegisterCommand
    extends CommandSupport
{
    RegisterCommand(final Shell shell) {
        super(shell, "register", "\\rc")
    }

    public Object execute(List args) {
        assert args != null

        if (args.size() < 1) {
            fail("Command 'register' requires at least 1 arguments") // TODO: i18n
        }

        String classname = args.get(0)

        Class type = getClassLoader().loadClass(classname)

        Command command = null;

        if (args.size() == 1) {                   // use default name
            command = type.newInstance(shell)
        }
        else if (args.size() == 2) {              // pass name to ctor
            command = type.newInstance(shell, args.get(1), null)
        }
        else if (args.size() == 3) {              // pass name, alias to ctor
            command = type.newInstance(shell, args.get(1), args.get(2))
        }

        def oldcommand = registry[command.name]   // let's prevent collisions

        if (oldcommand) {
            fail("Can not rebind command: ${command.name}") // TODO: i18n
        }

        if (log.debugEnabled) {
            log.debug("Created command '${command.name}': $command")
        }

        command = shell << command

        if (shell.runner) {
            shell.runner.completor << command
        }
    }
}