Why BPM contains only ABSTRACT messgae interfaces

Hi Forum,
Can u please help me in finding why BPM can only support ABSTRACT Message Interfaces.....
thanks
Edited by: sudeep dhar on Jan 16, 2008 9:28 AM

Sudeep,
Refer to http://help.sap.com/saphelp_nw04/helpdata/en/4b/d26b3d32390968e10000000a114084/frameset.htm for a description of the Communication Parameters
Alternatively, from the SDN SAP on DB2 for Linux, UNIX, and Windows you can pull up the SAP documentation for SAP XI 3.0 and enter the search term 'Abstract message'
Hope this helps,
Mike

Similar Messages

Unable to view Abstract Message Interface(Sync) in Container Step of BPM

Dear Friends,
This is IDOC---SOAP Sync Communication Interface
I have created the External Def by exporting & importing the Standard Idoc
and Imported the WSDL File which has the Request & response Structure
I have created the Outbound Sync message Interface for Idoc side
and Abstract Sync message Interface for the same to use in BPM
and also created Inbound Sync Message Interface for Webservice side
and Abstract Sync Message Interface for the same to use in BPM
Problem is::::
While creating the Container varible inside the Integration Process, i have to select the Abstract Message Interface which i created for Idoc.
But it is not at all visible in the list.
What might be the problem
REgards
Seshagiri

Hi,
I have created
For Idoc side
1) Create O/b Sync by having request of Idoc and response structure of Idoc
2) Create ABS Sync by having the request of Idoc and response structure of Idoc
3) Create ABS Async by having the Request of Idoc Only
For Webservice side
1) Create I/b Sync by having the request of webservice and response of that
2) Create ABS Sync by having the request of webservice and response of that
3) Create ABS Async by having the Response of Webservice only
I created the Steps inside the Integration Process as showed in the screens.
1)Integration Process graph
http://img145.imageshack.us/img145/4848/ipviewwv1.jpg
2)Receive Step
http://img293.imageshack.us/img293/1756/receivepropng8.jpg
3)Send step1
http://img179.imageshack.us/img179/2200/send1bd0.jpg
4)Send Step2
http://img182.imageshack.us/img182/8468/send2wl1.jpg
When i check the F7, it is throwing the error like
http://img247.imageshack.us/img247/4356/errortx3.jpg
Regards
Seshagiri

BPM Container for an abstract interface

Hello all,
I have created few abstract interfaces. But when I create a BPM container of type abstract interface and click on input help, abstract interfaces are not displayed. What might be the problem ?
Shankar.

hi,
try saving and activating the abstract interfaces
first
it might be a problem with the cache
but try activating the interfaces first
Regards,
michal
<a href="/people/michal.krawczyk2/blog/2005/06/28/xipi-faq-frequently-asked-questions">XI / PI FAQ - Frequently Asked Questions</a>

Container definition for Abstract Synchronus Interface

I am trying the simple scenario where the bpm process consumes soap request message (opens S/A bridge). After it queries another web services and sends back synchronously soap response, closing S/A bridge.
I've walked through different weblogs and forum posts but still not getting how the interface variables should be created in this case.
All my abstract interfaces are synchronous, and container definition for category "Abstract type" is only for Asynchronous interfaces.
Should I create two additional asynchronous interfaces with the same request/response message names to be able create interface variables?
And if message names are different in both soap calls should I create 4?
Thanks,
Evgeni
scenario is similar to the one described in the weblog https://www.sdn.sap.com/irj/sdn/weblogs?blog=/pub/wlg/1403 [original link is broken] [original link is broken] [original link is broken] [original link is broken] [original link is broken] [original link is broken] [original link is broken]
but without call to the legacy system and instead of JDBC it is another webservice.

Hi, thanks for replay,
>So this Abstract interface is used in the Receive step of the BPM(opening of the Sync/Async Bridge).
I've created Abs Sync interface and used it in the Receive step. My problem is I can not assign value to the Message Name in the step Properties.
To assign value I need first create container. To create container I need provide Type, which can be selected from the list of the "Message interfaces". But the list displays only Async Abs interfaces not Sync. How I should create container for Sync Request message?
Looking on the help link you provided. How I should create following:
Container
   Request
     BpmPatternBridgeRequest
   Response
     BpmPatternBridgeResponse
Kind regards,
Evgeni.

Usage of Abstract Message Interface for non-BPM

Hi,
I have a message that I am using as both as an inbound and an outbound for 2 different mapping. I am not using BPM. Is it better to create 2 message interfacesone for outbound and one for inboundor should I just create 1 abstract message interface that can be used in both mappings? What are the advantages and disadvantages of using 2 message interfaces (1 inbound and 1 outbound) against 1 abstract message interface? Would using abstract cause a lot of problems or performance problems in the future?
Thanks in advance.
Regards,
Elbert

hi,
abstract messages are only used for BPMs
so I suggest creating 2 instead if you don's use a BPM
http://help.sap.com/saphelp_nw2004s/helpdata/en/e3/3355d5617d0a4cb0fe8e042c752caa/content.htm
Regards,
michal
<a href="/people/michal.krawczyk2/blog/2005/06/28/xipi-faq-frequently-asked-questions">XI / PI FAQ - Frequently Asked Questions</a>

Abstract Class & Interfaces

Can anyone please tell me as to why we need both an abstract class & an interface? I was asked in an interview as to why we need 2 separate concepts when we can get the similar functionality of an interface by using an abstract class. I had just sited their differences like:
1) An abstract class can have both abstract & normal methods & that we can specify different access specifiers for its class members.
2) ABAP does not support Multiple inheritance but that we could simulate the same using interfaces concept in ABAP.
But he wasnt satisfied with the answer. I guess he was expecting something from a practical point of view. I did try searching the old threads but there wasnt anything similar to this. Anyone please explain by citing a scenario as to why we would need 2 separate concepts & not just one .
Thanks in advance

Hi
Abstract classes
Abstract classes are normally used as an incomplete blueprint for concrete (that is, non-abstract) subclasses, for example to define a uniform interface.
Classes with at least one abstract method are themselves abstract.
Static methods and constructors cannot be abstract.
You can specify the class of the instance to be created explicitly: CREATE OBJECT <RefToAbstractClass> TYPE <NonAbstractSubclassName>.
Abstarct classes themselves cant be instantiated ( althrough their subclasses can)
Reference to abstract classes can refer to instance of subclass
Abstract (instance) methods are difined in the class , but not implemented
They must be redefined in subclasses
CLASS LC1 DEFINAITION ABSTARCT
PUBLIC SECTION
METHODS ESTIMATE ABSTARCT IMPORTING
ENDCLASS.
Interfaces
Interfaces only describe the external point of contact of a class (protocols), they do not contain any implementation.
Interfaces are usually defined by a user. The user describes in the interface which services (technical and semantic) it needs in order to carry out a task.
The user never actually knows the providers of these services, but communicates with them through the interface.
In this way the user is protected from actual implementations and can work in the same way with different classes/objects, as long as they provide the services required. This is known as polymorphism with interfaces.

Abstract Class & Interface

Hi ,
I have a fundamental doubt regarding Abstract Class & Interface!!!
What is their real benefit...whether we implement an interface or extend an Abstract class we have to write the code for the abstract method in the concrete class.Then where the benefit remained....
And it is said that Abstract class provide default behaviour...what is the actual meaning of that?
Thanks & Regards
Santosh

In this section we will redesign our OneRowNim game to fit within a hierarchy of classes of two-player games. There are many games that characteristically involve two players: checkers, chess, tic-tac-toe, guessing games, and so forth. However, there are also many games that involve just one player: blackjack, solitaire, and others. There are also games that involve two or more players, such as many card games. Thus, our redesign of OneRowNim as part of a two-player game hierarchy will not be our last effort to design a hierarchy of game-playing classes. We will certainly redesign things as we learn new Java language constructs and as we try to extend our game library to other kinds of games.
This case study will illustrate how we can apply inheritance and polymorphism, as well as other object-oriented design principles. The justification for revising OneRowNim at this point is to make it easier to design and develop other two-player games. As we have seen, one characteristic of class hierarchies is that more general attributes and methods are defined in top-level classes. As one proceeds down the hierarchy, the methods and attributes become more specialized. Creating a subclass is a matter of specializing a given class.
8.6.1. Design Goals
One of our design goals is to revise the OneRowNim game so that it fits into a hierarchy of two-player games. One way to do this is to generalize the OneRowNim game by creating a superclass that contains those attributes and methods that are common to all two-player games. The superclass will define the most general and generic elements of two-player games. All two-player games, including OneRowNim, will be defined as subclasses of this top-level superclass and will inherit and possibly override its public and protected variables and methods. Also, our top-level class will contain certain abstract methods, whose implementations will be given in OneRowNim and other subclasses.
Generic superclass
A second goal is to design a class hierarchy that makes it possible for computers to play the game, as well as human users. Thus, for a given two-player game, it should be possible for two humans to play each other, or for two computers to play each other, or for a human to play against a computer. This design goal will require that our design exhibit a certain amount of flexibility. As we shall see, this is a situation in which Java interfaces will come in handy.
[Page 376]
Another important goal is to design a two-player game hierarchy that can easily be used with a variety of different user interfaces, including command-line interfaces and GUIs. To handle this feature, we will develop Java interfaces to serve as interfaces between our two-player games and various user interfaces.
8.6.2. Designing the TwoPlayerGame Class
To begin revising the design of the OneRowNim game, we first need to design a top-level class, which we will call the TwoPlayerGame class. What variables and methods belong in this class? One way to answer this question is to generalize our current version of OneRowNim by moving any variables and methods that apply to all two-player games up to the TwoPlayerGame class. All subclasses of TwoPlayerGamewhich includes the OneRowNim classwould inherit these elements. Figure 8.18 shows the current design of OneRowNim.
Figure 8.18. The current OneRowNim class.
What variables and methods should we move up to the TwoPlayerGame class? Clearly, the class constants, PLAYER_ONE and PLAYER_TWO, apply to all two-player games. These should be moved up. On the other hand, the MAX_PICKUP and MAX_STICKS constants apply just to the OneRowNim game. They should remain in the OneRowNim class.
The nSticks instance variable is a variable that only applies to the OneRowNim game but not to other two-player games. It should stay in the OneRowNim class. On the other hand, the onePlaysNext variable applies to all two-player games, so we will move it up to the TwoPlayerGame class.
Because constructors are not inherited, all of the constructor methods will remain in the OneRowNim class. The instance methods, takeSticks() and getSticks(), are specific to OneRowNim, so they should remain there. However, the other methods, getPlayer(), gameOver(), getWinner(), and reportGameState(), are methods that would be useful to all two-player games. Therefore these methods should be moved up to the superclass. Of course, while these methods can be defined in the superclass, some of them can only be implemented in subclasses. For example, the reportGameState() method reports the current state of the game, so it has to be implemented in OneRowNim. Similarly, the getWinner() method defines how the winner of the game is determined, a definition that can only occur in the subclass. Every two-player game needs methods such as these. Therefore, we will define these methods as abstract methods in the superclass. The intention is that TwoPlayerGame subclasses will provide game-specific implementations for these methods.
[Page 377]
Constructors are not inherited
Given these considerations, we come up with the design shown in Figure 8.19. The design shown in this figure is much more complex than the designs used in earlier chapters. However, the complexity comes from combining ideas already discussed in previous sections of this chapter, so don't be put off by it.
Figure 8.19. TwoPlayerGame is the superclass for OneRowNim and other two-player games.
To begin with, note that we have introduced two Java interfaces into our design in addition to the TwoPlayerGame superclass. As we will show, these interfaces lead to a more flexible design and one that can easily be extended to incorporate new two-player games. Let's take each element of this design separately.
[Page 378]
8.6.3. The TwoPlayerGame Superclass
As we have stated, the purpose of the TwoPlayerGame class is to serve as the superclass for all two-player games. Therefore, it should define the variables and methods shared by two-player games.
The PLAYER_ONE, PLAYER_TWO, and onePlaysNext variables and the getPlayer(), setPlayer(), and changePlayer() methods have been moved up from the OneRowNim class. Clearly, these variables and methods apply to all two-player games. Note that we have also added three new variables, nComputers, computer1, computer2, and their corresponding methods, getNComputers() and addComputerPlayer(). We will use these elements to give our games the capability to be played by computer programs. Because we want all of our two-player games to have this capability, we define these variables and methods in the superclass rather than in OneRowNim and subclasses of TwoPlayerGame.
Note that the computer1 and computer2 variables are declared to be of type IPlayer. IPlayer is an interface containing a single method declaration, the makeAMove() method:
public interface IPlayer {
public String makeAMove(String prompt);
Why do we use an interface here rather than some type of game-playing object? This is a good design question. Using an interface here makes our design more flexible and extensible because it frees us from having to know the names of the classes that implement the makeAMove() method. The variables computer1 and computer2 will be assigned objects that implement IPlayer via the addComputerPlayer() method.
Game-dependent algorithms
The algorithms used in the various implementations of makeAMove() are game-dependentthey depend on the particular game being played. It would be impossible to define a game playing object that would suffice for all two-player games. Instead, if we want an object that plays OneRowNim, we would define a OneRowNimPlayer and have it implement the IPlayer interface. Similarly, if we want an object that plays checkers, we would define a CheckersPlayer and have it implement the IPlayer interface. By using an interface here, our TwoPlayerGame hierarchy can deal with a wide range of differently named objects that play games, as long as they implement the IPlayer interface. Using the IPlayer interface adds flexibility to our game hierarchy and makes it easier to extend it to new, yet undefined, classes. We will discuss the details of how to design a game player in Section 8.6.7.
The IPlayer interface
Turning now to the methods defined in TwoPlayerGame, we have already seen implementations of getPlayer(), setPlayer(), and changePlayer() in the OneRowNim class. We will just move those implementations up to the superclass. The getNComputers() method is the assessor method for the nComputers variable, and its implementation is routine. The addComputerPlayer() method adds a computer player to the game. Its implementation is as follows:
[Page 379]
public void addComputerPlayer(IPlayer player) {
if (nComputers == 0)
computer2 = player;
else if (nComputers == 1)
computer1 = player;
else
return; // No more than 2 players
++nComputers;
As we noted earlier, the classes that play the various TwoPlayerGames must implement the IPlayer interface. The parameter for this method is of type IPlayer. The algorithm we use checks the current value of nComputers. If it is 0, which means that this is the first IPlayer added to the game, the player is assigned to computer2. This allows the human user to be associated with PLAYERONE if this is a game between a computer and a human user.
If nComputers equals 1, which means that we are adding a second IPlayer to the game, we assign that player to computer1. In either of these cases, we increment nComputers. Note what happens if nComputers is neither 1 nor 2. In that case, we simply return without adding the IPlayer to the game and without incrementing nComputers. This, in effect, limits the number of IPlayers to two. (A more sophisticated design would throw an exception to report an error. but we will leave that for a subsequent chapter.)
The addComputerPlayer() method is used to initialize a game after it is first created. If this method is not called, the default assumption is that nComputers equals zero and that computer1 and computer2 are both null. Here's an example of how it could be used:
OneRowNim nim = new OneRowNim(11); // 11 sticks
nim.add(new NimPlayer(nim)); // 2 computer players
nim.add(new NimPlayerBad(nim));
Note that the NimPlayer() constructor takes a reference to the game as its argument. Clearly, our design should not assume that the names of the IPlayer objects would be known to the TwoPlayerGame superclass. This method allows the objects to be passed in at runtime. We will discuss the details of NimPlayerBad in Section 8.6.7.
The getrules() method is a new method whose purpose is to return a string that describes the rules of the particular game. This method is implemented in the TwoPlayerGame class with the intention that it will be overridden in the various subclasses. For example, its implementation in TwoPlayerGame is:
public String getRules() {
return "The rules of this game are: ";
Overriding a method
[Page 380]
and its redefinition in OneRowNim is:
public String getRules() {
return "\n*** The Rules of One Row Nim ***\n" +
"(1) A number of sticks between 7 and " + MAX_STICKS +
" is chosen.\n" +
"(2) Two players alternate making moves.\n" +
"(3) A move consists of subtracting between 1 and\n\t" +
MAX_PICKUP +
" sticks from the current number of sticks.\n" +
"(4) A player who cannot leave a positive\n\t" +
" number of sticks for the other player loses.\n";
The idea is that each TwoPlayerGame subclass will take responsibility for specifying its own set of rules in a form that can be displayed to the user.
You might recognize that defining geTRules() in the superclass and allowing it to be overridden in the subclasses is a form of polymorphism. It follows the design of the toString() method, which we discussed earlier. This design will allow us to use code that takes the following form:
TwoPlayerGame game = new OneRowNim();
System.out.println(game.getRules());
Polymorphism
In this example the call to getrules() is polymorphic. The dynamic-binding mechanism is used to invoke the getrules() method defined in the OneRowNim class.
The remaining methods in TwoPlayerGame are defined abstractly. The gameOver() and getWinner() methods are both game-dependent methods. That is, the details of their implementations depend on the particular TwoPlayerGame subclass in which they are implemented.
This is good example of how abstract methods should be used in designing a class hierarchy. We give abstract definitions in the superclass and leave the detailed implementations up to the individual subclasses. This allows the different subclasses to tailor the implementations to their particular needs, while allowing all subclasses to share a common signature for these tasks. This enables us to use polymorphism to create flexible, extensible class hierarchies.
Figure 8.20 shows the complete implementation of the abstract TwoPlayerGame class. We have already discussed the most important details of its implementation.
Figure 8.20. The TwoPlayerGame class
(This item is displayed on page 381 in the print version)
public abstract class TwoPlayerGame {
public static final int PLAYER_ONE = 1;
public static final int PLAYER_TWO = 2;
protected boolean onePlaysNext = true;
protected int nComputers = 0; // How many computers
// Computers are IPlayers
protected IPlayer computer1, computer2;
public void setPlayer(int starter) {
if (starter == PLAYER_TWO)
onePlaysNext = false;
else onePlaysNext = true;
} // setPlayer()
public int getPlayer() {
if (onePlaysNext)
return PLAYER_ONE;
else return PLAYER_TWO;
} // getPlayer()
public void changePlayer() {
onePlaysNext = !onePlaysNext;
} // changePlayer()
public int getNComputers() {
return nComputers;
} // getNComputers()
public String getRules() {
return "The rules of this game are: ";
} // getRules()
public void addComputerPlayer(IPlayer player) {
if (nComputers == 0)
computer2 = player;
else if (nComputers == 1)
computer1 = player;
else
return; // No more than 2 players
++nComputers;
} // addComputerPlayer()
public abstract boolean gameOver(); // Abstract Methods
public abstract String getWinner();
} // TwoPlayerGame class
Effective Design: Abstract Methods
Abstract methods allow you to give general definitions in the superclass and leave the implementation details to the different subclasses.
[Page 381]
8.6.4. The CLUIPlayableGame Interface
We turn now to the two interfaces shown in Figure 8.19. Taken together, the purpose of these interfaces is to create a connection between any two-player game and a command-line user interface (CLUI). The interfaces provide method signatures for the methods that will implement the details of the interaction between a TwoPlayerGame and a UserInterface. Because the details of this interaction vary from game to game, it is best to leave the implementation of these methods to the games themselves.
Note that CLUIPlayableGame extends the IGame interface. The IGame interface contains two methods that are used to define a standard form of communication between the CLUI and the game. The getGamePrompt() method defines the prompt used to signal the user for a move of some kindfor example, "How many sticks do you take (1, 2, or 3)?" And the reportGameState() method defines how the game will report its current statefor example, "There are 11 sticks remaining." CLUIPlayableGame adds the play() method to these two methods. As we will see shortly, the play() method contains the code that will control the playing of the game.
[Page 382]
Extending an interface
The source code for these interfaces is very simple:
public interface CLUIPlayableGame extends IGame {
public abstract void play(UserInterface ui);
public interface IGame {
public String getGamePrompt();
public String reportGameState();
} // IGame
Note that the CLUIPlayableGame interface extends the IGame interface. A CLUIPlayableGame is a game that can be played through a CLUI. The purpose of its play() method is to contain the game-dependent control loop that determines how the game is played via a user interface (UI). In pseudocode, a typical control loop for a game would look something like the following:
Initialize the game.
While the game is not over
Report the current state of the game via the UI.
Prompt the user (or the computer) to make a move via the UI.
Get the user's move via the UI.
Make the move.
Change to the other player.
The play loop sets up an interaction between the game and the UI. The UserInterface parameter allows the game to connect directly to a particular UI. To allow us to play our games through a variety of UIs, we define UserInterface as the following Java interface:
public interface UserInterface {
public String getUserInput();
public void report(String s);
public void prompt(String s);
Any object that implements these three methods can serve as a UI for one of our TwoPlayerGames. This is another example of the flexibility of using interfaces in object-oriented design.
To illustrate how we use UserInterface, let's attach it to our KeyboardReader class, thereby letting a KeyboardReader serve as a CLUI for TwoPlayerGames. We do this simply by implementing this interface in the KeyboardReader class, as follows:
public class KeyboardReader implements UserInterface
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As it turns out, the three methods listed in UserInterface match three of the methods in the current version of KeyboardReader. This is no accident. The design of UserInterface was arrived at by identifying the minimal number of methods in KeyboardReader that were needed to interact with a TwoPlayerGame.
Effective Design: Flexibility of Java Interfaces
A Java interface provides a means of associating useful methods with a variety of different types of objects, leading to a more flexible object-oriented design.
The benefit of defining the parameter more generally as a UserInterface instead of as a KeyboardReader is that we will eventually want to allow our games to be played via other kinds of command-line interfaces. For example, we might later define an Internet-based CLUI that could be used to play OneRowNim among users on the Internet. This kind of extensibilitythe ability to create new kinds of UIs and use them with TwoPlayerGamesis another important design feature of Java interfaces.
Generality principle
Effective Design: Extensibility and Java Interfaces
Using interfaces to define useful method signatures increases the extensibility of a class hierarchy.
As Figure 8.19 shows, OneRowNim implements the CLUIPlayableGame interface, which means it must supply implementations of all three abstract methods: play(), getGamePrompt(), and reportGameState().
8.6.5. Object-Oriented Design: Interfaces or Abstract Classes?
Why are these methods defined in interfaces? Couldn't we just as easily define them in the TwoPlayerGame class and use inheritance to extend them to the various game subclasses? After all, isn't the net result the same, namely, that OneRowNim must implement all three methods.
These are very good design questions, exactly the kinds of questions one should ask when designing a class hierarchy of any sort. As we pointed out in the Animal example earlier in the chapter, you can get the same functionality from an abstract interface and an abstract superclass method. When should we put the abstract method in the superclass, and when does it belong in an interface? A very good discussion of these and related object-oriented design issues is available in Java Design, 2nd Edition, by Peter Coad and Mark Mayfield (Yourdan Press, 1999). Our discussion of these issues follows many of the guidelines suggested by Coad and Mayfield.
Interfaces vs. abstract methods
We have already seen that using Java interfaces increases the flexibility and extensibility of a design. Methods defined in an interface exist independently of a particular class hierarchy. By their very nature, interfaces can be attached to any class, and this makes them very flexible to use.
Flexibility of interfaces
Another useful guideline for answering this question is that the superclass should contain the basic common attributes and methods that define a certain type of object. It should not necessarily contain methods that define certain roles that the object plays. For example, the gameOver() and getWinner() methods are fundamental parts of the definition of a TwoPlayerGame. One cannot define a game without defining these methods. By contrast, methods such as play(), getGamePrompt(), and reportGameState() are important for playing the game but they do not contribute in the same way to the game's definition. Thus these methods are best put into an interface. Therefore, one important design guideline is:
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Effective Design: Abstract Methods
Methods defined abstractly in a superclass should contribute in a fundamental way to the basic definition of that type of object, not merely to one of its roles or its functionality.
8.6.6. The Revised OneRowNim Class
Figure 8.21 provides a listing of the revised OneRowNim class, one that fits into the TwoPlayerGame class hierarchy. Our discussion in this section will focus on the features of the game that are new or revised.
Figure 8.21. The revised OneRowNim class, Part I.
(This item is displayed on page 385 in the print version)
public class OneRowNim extends TwoPlayerGame implements CLUIPlayableGame {
public static final int MAX_PICKUP = 3;
public static final int MAX_STICKS = 11;
private int nSticks = MAX_STICKS;
public OneRowNim() { } // Constructors
public OneRowNim(int sticks) {
nSticks = sticks;
} // OneRowNim()
public OneRowNim(int sticks, int starter) {
nSticks = sticks;
setPlayer(starter);
} // OneRowNim()
public boolean takeSticks(int num) {
if (num < 1 || num > MAX_PICKUP || num > nSticks)
return false; // Error
else // Valid move
{ nSticks = nSticks - num;
return true;
} // else
} // takeSticks()
public int getSticks() {
return nSticks;
} // getSticks()
public String getRules() {
return "\n*** The Rules of One Row Nim ***\n" +
"(1) A number of sticks between 7 and " + MAX_STICKS +
" is chosen.\n" +
"(2) Two players alternate making moves.\n" +
"(3) A move consists of subtracting between 1 and\n\t" +
MAX_PICKUP + " sticks from the current number of sticks.\n" +
"(4) A player who cannot leave a positive\n\t" +
" number of sticks for the other player loses.\n";
} // getRules()
public boolean gameOver() { /*** From TwoPlayerGame */
return (nSticks <= 0);
} // gameOver()
public String getWinner() { /*** From TwoPlayerGame */
if (gameOver()) //{
return "" + getPlayer() + " Nice game.";
return "The game is not over yet."; // Game is not over
} // getWinner()
The gameOver() and getWinner() methods, which are nowinherited from the TwoPlayerGame superclass, are virtually the same as in the previous version. One small change is that getWinner() now returns a String instead of an int. This makes the method more generally useful as a way of identifying the winner for all TwoPlayerGames.
Similarly, the getGamePrompt() and reportGameState() methods merely encapsulate functionality that was present in the earlier version of the game. In our earlier version the prompts to the user were generated directly by the main program. By encapsulating this information in an inherited method, we make it more generally useful to all TwoPlayerGames.
Inheritance and generality
The major change to OneRowNim comes in the play() method, which controls the playing of OneRowNim (Fig. 8.22). Because this version of the game incorporates computer players, the play loop is a bit more complex than in earlier versions of the game. The basic idea is still the same: The method loops until the game is over. On each iteration of the loop, one or the other of the two players, PLAYER_ONE or PLAYER_TWO, takes a turn making a movethat is, deciding how many sticks to pick up. If the move is a legal move, then it becomes the other player's turn.
Figure 8.22. The revised OneRowNim class, Part II.
(This item is displayed on page 386 in the print version)
/** From CLUIPlayableGame */
public String getGamePrompt() {
return "\nYou can pick up between 1 and " +
Math.min(MAX_PICKUP,nSticks) + " : ";
} // getGamePrompt()
public String reportGameState() {
if (!gameOver())
return ("\nSticks left: " + getSticks() +
" Who's turn: Player " + getPlayer());
else
return ("\nSticks left: " + getSticks() +
" Game over! Winner is Player " + getWinner() +"\n");
} // reportGameState()
public void play(UserInterface ui) { // From CLUIPlayableGame interface
int sticks = 0;
ui.report(getRules());
if (computer1 != null)
ui.report("\nPlayer 1 is a " + computer1.toString());
if (computer2 != null)
ui.report("\nPlayer 2 is a " + computer2.toString());
while(!gameOver()) {
IPlayer computer = null; // Assume no computers
ui.report(reportGameState());
switch(getPlayer()) {
case PLAYER_ONE: // Player 1's turn
computer = computer1;
break;
case PLAYER_TWO: // Player 2's turn
computer = computer2;
break;
} // cases
if (computer != null) { // If computer's turn
sticks = Integer.parseInt(computer.makeAMove(""));
ui.report(computer.toString() + " takes " + sticks + " sticks.\n");
} else { // otherwise, user's turn
ui.prompt(getGamePrompt());
sticks =
Integer.parseInt(ui.getUserInput()); // Get user's move
if (takeSticks(sticks)) // If a legal move
changePlayer();
} // while
ui.report(reportGameState()); // The game is now over
} // play()
} // OneRowNim class
Let's look now at how the code decides whether it is a computer's turn to move or a human player's turn. Note that at the beginning of the while loop, it sets the computer variable to null. It then assigns computer a value of either computer1 or computer2, depending on whose turn it is. But recall that one or both of these variables may be null, depending on how many computers are playing the game. If there are no computers playing the game, then both variables will be null. If only one computer is playing, then computer1 will be null. This is determined during initialization of the game, when the addComputerPlayer() is called. (See above.)
In the code following the switch statement, if computer is not null, then we call computer.makeAMove(). As we know, the makeAMove() method is part of the IPlayer interface. The makeAMove() method takes a String parameter that is meant to serve as a prompt, and returns a String that is meant to represent the IPlayer's move:
public interface IPlayer {
public String makeAMove(String prompt);
[Page 385]
In OneRowNim the "move" is an integer, representing the number of sticks the player picks. Therefore, in play() OneRowNim has to convert the String into an int, which represents the number of sticks the IPlayer picks up.
On the other hand, if computer is null, this means that it is a human user's turn to play. In this case, play() calls ui.getUserInput(), employing the user interface to input a value from the keyboard. The user's input must also be converted from String to int. Once the value of sticks is set, either from the user or from the IPlayer, the play() method calls takeSticks(). If the move is legal, then it changes whose turn it is, and the loop repeats.
[Page 386]
There are a couple of important points about the design of the play() method. First, the play() method has to know what to do with the input it receives from the user or the IPlayer. This is game-dependent knowledge. The user is inputting the number of sticks to take in OneRowNim. For a tic-tac-toe game, the "move" might represent a square on the tic-tac-toe board. This suggests that play() is a method that should be implemented in OneRowNim, as it is here, because OneRowNim encapsulates the knowledge of how to play the One-Row Nim game.
Encapsulation of game-dependent knowledge
[Page

How to Access a BPM container variable in XI graphical message mapping

Hello XI BPM and Mapping experts,
is it possible to access a BPM container variable from an graphical mapping?
If yes, how ?
We need this for the following scenario:
IDOC to BPM.
BPM transforms and sends transformed IDOC to fileadapter
If both steps are successful a STATUS.SYSTAT01 IDOC should be send back to SAP-ISU with status 06.
If one of these steps fails the status in the SYSTAT01 should be set to 05. (Exception branch of block)
We want to avoid to write 2 mapping programs for mapping the SYSTAT01.
Instead we would like to use a BPM Container Variable which contains the status.
In the mapping for the SYSTAT01 we want to use this Container Variable.
Is this possible?
Thanks for soon answers.
Regards Marlies

Hi Marlies,
Is not possible to acces a BPM container variable from graphical mapping. For other hand, you can to use runtime variables for this purpose.
You could create an abstract interface with a message type having a single node with the required value and using this message in other mapping.
Best regards
Ivá

SOAP XI scenario, ambiguity in Abstract Message Interface

Hi Forum,
I have a SOAP client(synchronous)--->XI scenario,
let me describe the scenario,
Step1. SOAP client sends a SOAP request to the BPM in XI, using a synchronous receive step (Abstract synchronous MI),
Step 2. in BPM, it does some transformation
Step 3. the response of the step 2, is then sent as the response for the SOAP client request, using a Synchronous send (sync async bridge maintained),
Step 4. i use the abstract Synchronous MI (for the SOAP client to send request), to create a WSDL, and use it in ALTOVA to create SOAP request automatically,
now the problem is, In integration builder, Design,.........
when i make the abstract Synchronous MI (for the SOAP client to send request), i use 2 message types RequestMessage (output message) and ResponseMessage (input message), ******sounds bit oppsosite ..but it is like that only......but the source of ambiguity
but when i create the WSDL using the web service creation tool, in integration builder, Configuration, ....... the WSDL is bit unexpected, it shows input as ResponeMessage and output as RequestMessage....hmm.....as such i cant use that WSDL in any tool like altova to create the SOAP request automatically....
****the source of all ambiguity is....in the screen for creating the Message interface (as Synchronous abstract/outboud), we give OUTPUT MESSAGE as the input message type and vice versa...
do u agree.......
am i wrong?
in that case how can i make a correct WSDL

Let us discuss point by point.
You are doing a scenario SOAP to XI with no end point on the other side. Means you are using XI as the end point for simulating. This is my assumption.
Step1. SOAP client sends a SOAP request to the BPM in XI, using a synchronous receive step (Abstract synchronous MI),
Ok.
Step 2. in BPM, it does some transformation
Ok
Step 3. the response of the step 2, is then sent as the response for the SOAP client request, using a Synchronous send (sync async bridge maintained),
You should not use a synchronous send step here. You should be using an Async send here. The sync asyn bridge must start in the first receive step and end here.
Step 4. i use the abstract Synchronous MI (for the SOAP client to send request), to create a WSDL, and use it in ALTOVA to create SOAP request automatically,
You shuld create the WSDL for the Outbound Synchronous message interface which should have been created to supply the message to Abstract Synchronous interface. Then only you will be able to test the message.
So.. you need totally
1. OB Syn MI
2. Abstrac Syn MI (Receive in BPM)
3. Abstract Async MI (to send response to SOAP caller)
VJ

Requirement of a abstract message interface

Hello,
I wonder when to use abstract message interfaces?
The documentations says:
An abstract message interface has no implementation in an application system. You cannot generate a proxy for this interface type. You use abstract interfaces in business processes, for example, to receive or send messages from application systems. You can use the same abstract interface to receive or to send.
What does IMPLEMENTATION mean in this context? Can anybody discribe a concrete need for abstract message interfaces?
Thank You

Hi Mario,
you only use those interfaces inside a BPM:
send step, receive step, transformations etc
(no other use)
- you cannot create proxies from it
- you must have an normal (not abstract) interface
to send data to XI or to receive data
(so once you create everything inside your integration process - with the use of abstract interfaces)
inside ID you still have to use standard interfaces
(outbound or inbound)
Regards,
michal
Message was edited by: Michal Krawczyk

Why ABC's are more powerful 'interfaces' than interfaces

A simple answer as to what the value of Abstract Base Classes are is that
(1) They act like Interfaces, allowing for polymorphic abstraction of multiple implementations
(2) They allow for default implementations, but insist on derivation
For this question, please set aside any value that default implementations provide, and concentrate only on the 'interface'-like qualities of ABCs.
Why did sun decide to make ABCs more powerful as interfaces, than interfaces themselves.
Or... asked another way, in the following code snippet
public void doCoolStuff( ObjectOutputStream os, Fooable foo )
throws CloneNotSupportedException, IOException
    Fooable foo2 = (Fooable)foo.clone();
    foo2.changeMyselfSomehow();
    os.writeObject(foo2);
}If I said the Fooable 'thingy' has absolutely no implementation attached to it whatsoever, then, what kind of thingy is Fooable?

Functionally: A class can only extend one class,even
if the parent is an ABC, but it can inherit multiple
interfaces. public class Foo extends ABC1,ABC2
{} // won't compile
Yes that's the common logic. And yet Fooable
absolutely can not be an interface, but can be
an ABC.Interfaces can do X that ABCs can't do. ABCs can do Y that interfaces can't do. Which is more powerful?
This box is longer, but that box is wider. Which is bigger?

Container Object - type Abstrace Interface

Hi everyone,
When I try to create a container Object in BPM of category Abs. Interface, for the type, it gets the Async Abs Interfaces only from the IR but not Sync Abs Interfaces.
Is there any reason for this. It is on sync send step.
-Naveen.

Hi,
Yes, you will not get Sync Abs interface over there.
For this you need to create 2 message containers one with Req and Resp containers . So inorder to receive the Sync Interface message in the BPM, you need to use Sync/Async Bridge open.
http://help.sap.com/saphelp_nw2004s/helpdata/en/43/65d4dab39b0398e10000000a1553f6/content.htm
Regards,
Moorthy

Why I can only download 20 photos for last month from the photostream while I have more than 3GB photos kept in iCloud? Many thanks.

Why I can only download 20 photos for last month from the photostream while I have more than 3GB photos kept in iCloud? My iPhone was stolen and the photos in it are very precious to me. Many thanks.

On a new device you can only download what is currently stored in "My Photo Stream" in iCloud. iCloud keeps up to the last 1000 photos, but only the photos, that have been added during the last month. Older photos may be removed, when the time is up. On other devices you may be seeing older photos as well in "My Photo Stream", that will depend on the available storage on those devices, and when the Photo Stream has been enabled on those devices, see: My Photo Stream FAQ - Apple Support
If you are seeing other photos in the Photo Stream on other devices, that you want to save, mail them to you from the other devices.
Have you tried to restore your iPhone from the last iCloud backup of the old phone? The backup will contain the photos in the Camera Roll, but not the photos in Photo Stream. iOS: Back up and restore your iOS device with iCloud or iTunes

Accessing a BPM Container Variable Inside A Mapping

Hi
Is It possible to access a BPM container variable (Simple type say a String )in a Mapping (message mapping). This mapping is present in the same BPM itself. Is it possible to access the variable in the mapping.
My basic objective is i need to read and update values between My message mapping and Bpm container simple type variable. I read a value from BPM variable and then update this variable and again write it back to the BPM container variable and then again read it in a loop . Is it possible to do this exchange.

Hi,
The only way is to do with mapping. Totally you need to add your conatiner values into message and then thru mapping you can access.
Using Container Operation-Append
http://help.sap.com/saphelp_nw04/helpdata/en/59/e1283f2bbad036e10000000a114084/content.htm
Regards,
Moorthy

Abstract Classes & Interface Classes

Dear members of the Sun Community
My studies are progressing and just 1 period ago we started doing Object-Orinted Programming in Java and I must say I'm quite fond of it. It's become quite clear that OOP is an important aspect of Programming and just can't be missed. We've learned about Inheritance, Polymorfism, Mutators, Inspectors, Uses-Relationships and everything else however now I've come to the point where I got a problem:
Up until now we have been using normal classes to work with in which you could create objects and in your main program create objects from that class however. We've just learned about Abstract and Interface classes. As far as I'm concerned I'm quite confused with both of them.
If I am not mistaken (please correct me if I'm wrong) Abstract classes are classes from which you cannot create an object but is only used to make a subclass inherit everything from this superclass.
I am not quite sure what Interface classes are as they just plain confuse me. Would anyone be so kind to maybe explain what all of this is ?
Thanks a whole bunch
Herazio

Funny enough that already solved the question !
Thank you so much for the quick reply ^^
Herazio

Why BPM contains only ABSTRACT messgae interfaces

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