Welcome to the jungle, where the animals are not only wild but also quite aggressive! Let’s see how to code a poker betting game in pure Java. It doesn’t get much simpler than this: we will be creating a Java application where users will place bets on the outcome of a poker game. The application will take in account all of the relevant rules and regulations in order to properly execute the transactions made by users. Let’s get to work.
The Low Hanging Fruit
Before we start coding, let’s take a quick detour to discuss the requirements of this particular project. This application will be based on certain design principles which will make it more organized and easier to maintain. One of the most important things to keep in mind is that we need to follow established practices whenever possible. Another principle worth considering is to always opt for the simplest solution; in this case, if we take a step back, we will realize that our requirements are quite simple and can be completely satisfied by leveraging off-the-shelf java library classes. With that said, let’s dive into the coding.
The Poker Game
As stated above, this application will allow users to place bets on the outcome of a poker game. For the sake of this example, let’s assume that we are dealing with Texas Hold’em poker. The rules and regulations of this particular game model are fairly simple, and are as follows:
- Each player is dealt two cards face down
- Each player is allowed to look at their cards, but not show them to anyone else
- Players must place their bets before the commencement of the first round of betting
- The dealer’s card is revealed at the end of the hand
- The player with the highest card wins
- Players can change their bets as often as they want during the game
- There is a continuous betting round, where players can adjust their bets as often as they want
- Players are not allowed to make duplicate bets
- Players must declare their intentions to the dealer at the beginning of each round; this is to ensure that nobody rigs the game in favour of another player
- A player’s hand is determined by the two cards dealt to them and the sum of their bets
- The dealer’s function is to take in account all of the bets placed and to randomly deal out cards to the players
- If two players’ hands are tied, the game results are a push
- Players are required to follow all relevant betting rounds and to keep track of their own bets
Since we already have the rules of the game laid down, we can start creating the application. With that said, let’s write some Java code to model the game:
As we mentioned above, this application will allow users to place bets on the outcome of a poker game. In order to keep things organized, let’s create a separate class to model the game. This class will serve as the foundation of our application and will encapsulate all of the logic required by the poker game rules. As such, this class will contain only minimal constructors which will be used to initialize the class with the necessary values. In the next section, let’s discuss how to create this class.
Game Rules And Initialization
This class will adhere to certain software design conventions that will make it easier for other programmers to follow along and understand its logic. One of the most important things to keep in mind is that this class will be used as the basis for our application, and as such, it will not directly interact with the users. For that reason, all of the members of this class will be private, except for the main constructor:
- Sets up private variables that will be used throughout the class
- Implements the necessary operations required by the rules of the poker game
- Creates a private instance variable to store the dealer’s card
- Creates private instances for each player to store their two cards
- Declares a private constructor to avoid instantiating this class
- Implements the necessary checks to ensure that the class follows the rules of Texas Hold’em Poker
Once we have a class for modeling the game, let’s move on to the next step.
The Database Persistance
If our application is going to be an interactive one where users are going to be making frequent transactions, then we need to find a way to save the state of the application between sessions. For this reason, let’s create a separate class to handle the database persistence of this application. This class will keep track of all of the transactions that are made by the users and will ensure that the states of the application are persisted in a reliable manner. Let’s call this class the TransactionManager:
In this class, we will encapsulate all of the logic required by the database persistence of the application. This class will have two main responsibilities:
- Track the states of our application, and ensure that these states are saved coherently
- Allow users to make transactions, and keep track of the actions taken by the users
As you can see, this class will have a single instance variable which will be of type HashMap. The reason for this is simple: we do not want to directly access the database from this class. For this reason, we are using a Map to store the data as a concierge of sorts; the database access will be handled by a separate class, the DBConfiguration.
The HashMap will save all of the states of our application as keys and values. These keys will be Strings which will denote the state of the application at a given moment (e.g., “NEW_GAME”,”USER_LOGGED_IN”,”BETTING_ONGOING”,”FINAL_ROLL” ).
As a result of these keys, this map will contain a wealth of information about the current status of the application. This map will have several getters and setters, and these will be used to read and write to the database. For example, the getUserLoggedIn() method will return true if the user is currently logged in, and false otherwise.
The class will also have a single method which will be used to persist the states of our application. This method will take in a HashMap
The reason we need to handle the persistence of the application is simple: if a user is not logged in, then they will not have a means to interact with the application. For this reason, let’s ensure that the application will remain functional even if the user is not logged in. When the user logs in, we will need to ensure that their details are stored in the database and that all of the relevant states are restored when they log out.
The Presentation Layer
Since this is a GUI application, we need to create a separate class to handle the user interface. For the sake of convenience, let’s call this class the UI Manager:
The role of the UI Manager will be to take care of all of the interactions which can be made by the users with the application. This class will have two responsibilities:
- Present the information to be displayed to the user
- Take in account the states of our application, and present the user with relevant feedback
As we mentioned above, this application will allow users to place bets on the outcome of a poker game. For the sake of this example, let’s assume that we are dealing with a standard deck of cards, where each card is valued at its face value. For this reason, we will not need to worry about dealing with currency issues in this application. Let’s also assume that all of the players are using real money, and that they are ready to place their bets. As a result, this application is now in a position to start accepting bets from the users.
Since we have a class to take care of the database persistence of our application, let’s move on to the next step.