com.aspectran.daemon.command.Command Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2019 The Aspectran Project
*
* 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 com.aspectran.daemon.command;
import com.aspectran.daemon.command.polling.CommandParameters;
/**
* The Command interface is there to allow Commander to delegate tasks.
*/
public interface Command {
/**
* Returns whether it is a command that must be guaranteed not to be executed
* at the same time as another command.
*
* @return true if the command should ensure that it is not executed at the same
* time as another command; false otherwise
*/
boolean isIsolated();
/**
* This method will be called as the starting point to execute the logic
* for the action mapped to this command.
*
* @param parameters the command parameters
* @return the message output to the console as a result of an executed command
*/
CommandResult execute(CommandParameters parameters);
/**
* This method returns an instance of Command.Descriptor.
* The descriptor is meta information about the command.
*
* @return a Descriptor that is meta information about the command
*/
Command.Descriptor getDescriptor();
/**
* An interface that can be used to describe the the functionality of the
* command implementation. This is a very important concept in a text-driven
* environment such as a command-line user interface.
*/
interface Descriptor {
/**
* The purpose of the namespace is to provide an identifier to group
* commands without relying on class name or other convoluted approaches
* to group commands.
*
* @return the command's namespace
*/
String getNamespace();
/**
* Implementation of this method should return a simple string (with no spaces)
* that identifies the action mapped to this command.
*
* @return the name of the action mapped to this command.
*/
String getName();
/**
* This method should return a descriptive text about the command
* it is attached to.
*
* @return a descriptive text about the command
*/
String getDescription();
}
}