Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations. Builds an undo/redo manager and a set of  command classes.

Source Code

/**  * Declares an interface for executing an operation  * @role __Command  */ public interface Command {         /** this method is called by client to execute this command */         void executeCommand();}  /**  * Defines a binding betweeen a Receiver object and an action.   * Implements Command by invoking the corresponding operation(s) on Receiver  */ public class CommandA implements Command {         public CommandA() {                 // put command initialization code here         }          /** @see patterns.gof.command.Command#executeCommand()*/         public void executeCommand() {                 // provide implementation here         } }  /**  * Defines a binding betweeen a Receiver object and an action.   * Implements Command by invoking the corresponding operation(s) on Receiver  */ public class CommandB implements Command {         public CommandB() {                 // put command initialization code here         }          /** @see patterns.gof.command.Command#executeCommand()*/         public void executeCommand() {                 // provide implementation here         } }  /**  * Concrete Command that executes a sequence of Commands.  */ public class MacroCommand implements Command {         /** Commands to execute */         private Command[] commands;        /** @param commands Commands to execute */         public MacroCommand(Command[] commands) {                 this.commands = commands;        }          /** Executes sequence of Commands */         public void executeCommand() {                 if (commands != null) {                         for (int i = 0; i < commands.length; i++) {                                 commands[i].executeCommand();                        }                 }         }  }