[jdjlist] Re: Command design pattern

[Madhav Vodnala]

Here is the example code snippet from Bruce Eckel's Thinking In Patterns.

// CommandPattern.java
import java.util.*;
import com.bruceeckel.test.*;

interface Command {
  void execute();
}

class Hello implements Command {
  public void execute() {
    System.out.print("Hello ");
  }
}

class World implements Command {
  public void execute() {
    System.out.print("World! ");
  }
}

class IAm implements Command {
  public void execute() {
    System.out.print("I'm the command pattern!");
  }
}

// An object that holds commands:
class Macro {
  private List commands = new ArrayList();
  public void add(Command c) { commands.add(c); }
  public void run() {
    Iterator it = commands.iterator();
    while(it.hasNext())
      ((Command)it.next()).execute();
  }
}

public class CommandPattern extends UnitTest {
  Macro macro = new Macro();
  public void test() {
    macro.add(new Hello());
    macro.add(new World());
    macro.add(new IAm());
    macro.run();
  }
  public static void main(String args[]) {
    new CommandPattern().test();
  }
} ///:~


----- Original Message -----
From: "jayaraman sureshkumar" <[EMAIL PROTECTED]>
To: "JDJList" <[EMAIL PROTECTED]>
Sent: Tuesday, June 18, 2002 4:03 PM
Subject: [jdjlist] Command design pattern


> Hello,
>
> I need to know a simple example explaining the subject design pattern in a
> nut shell.. please help..
>
> Thanks
>
> Suresh
>
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