用java写一个五子棋

好的，以下是一个简单的五子棋的 Java 实现。

import java.util.Scanner;

public class Gomoku {
    private static int ROWS = 15;
    private static int COLS = 15;
    private static char BLANK = '-';
    private static char BLACK = 'X';
    private static char WHITE = 'O';
    private static char[][] board = new char[ROWS][COLS];
    private static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        initBoard();
        printBoard();

        char player = BLACK;
        while (true) {
            System.out.println("Player " + player + "'s turn.");
            int row = getValidInput("Enter row: ");
            int col = getValidInput("Enter col: ");

            if (board[row][col] != BLANK) {
                System.out.println("This cell is occupied. Please select another cell.");
                continue;
            }

            board[row][col] = player;
            printBoard();

            if (checkWin(row, col)) {
                System.out.println("Player " + player + " wins!");
                break;
            }

            if (isBoardFull()) {
                System.out.println("The game is a draw!");
                break;
            }

            player = (player == BLACK) ? WHITE : BLACK;
        }
    }

    private static void initBoard() {
        for (int i = 0; i < ROWS; i++) {
            for (int j = 0; j < COLS; j++) {
                board[i][j] = BLANK;
            }
        }
    }

    private static void printBoard() {
        System.out.print("  ");
        for (int j = 0; j < COLS; j++) {
            System.out.print(j + " ");
        }
        System.out.println();

        for (int i = 0; i < ROWS; i++) {
            System.out.print(i + " ");
            for (int j = 0; j < COLS; j++) {
                System.out.print(board[i][j] + " ");
            }
            System.out.println();
        }
    }

    private static int getValidInput(String prompt) {
        int input;
        while (true) {
            System.out.print(prompt);
            try {
                input = sc.nextInt();
                if (input < 0 || input >= ROWS) {
                    System.out.println("Invalid input. Please enter a number between 0 and " + (ROWS - 1) + ".");
                    continue;
                }
                break;
            } catch (Exception e) {
                System.out.println("Invalid input. Please enter a number between 0 and " + (ROWS - 1) + ".");
                sc.nextLine();
            }
        }
        return input;
    }

    private static boolean checkWin(int row, int col) {
        char player = board[row][col];
        int count;

        // check horizontal
        count = 1;
        for (int j = col - 1; j >= 0 && board[row][j] == player; j--) {
            count++;
        }
        for (int j = col + 1; j < COLS && board[row][j] == player; j++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        // check vertical
        count = 1;
        for (int i = row - 1; i >= 0 && board[i][col] == player; i--) {
            count++;
        }
        for (int i = row + 1; i < ROWS && board[i][col] == player; i++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        // check diagonal (top-left to bottom-right)
        count = 1;
        for (int i = row - 1, j = col - 1; i >= 0 && j >= 0 && board[i][j] == player; i--, j--) {
            count++;
        }
        for (int i = row + 1, j = col + 1; i < ROWS && j < COLS && board[i][j] == player; i++, j++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        // check diagonal (bottom-left to top-right)
        count = 1;
        for (int i = row + 1, j = col - 1; i < ROWS && j >= 0 && board[i][j] == player; i++, j--) {
            count++;
        }
        for (int i = row - 1, j = col + 1; i >= 0 && j < COLS && board[i][j] == player; i--, j++) {
            count++;
        }
        if (count >= 5) {
            return true;
        }

        return false;
    }

    private static boolean isBoardFull() {
        for (int i = 0; i < ROWS; i++) {
            for (int j = 0; j < COLS; j++) {
                if (board[i][j] == BLANK) {
                    return false;
                }
            }
        }
        return true;
    }
}

这个实现中，我们使用了一个二维 char 数组来表示棋盘，其中 `-` 表示空格，`X` 表示黑棋，`O` 表示白棋。我们在 `main` 方法中实现了游戏的主要逻辑：

1. 初始化棋盘并打印出来。
2. 循环进行游戏，每次轮到一个玩家时，要求玩家输入下棋的坐标。
3. 检查该位置是否已经被占据，如果被占据则提示玩家重新选择。
4. 将该位置标记为玩家的棋子，并打印出来。
5. 检查是否有玩家获胜或者棋盘已满，如果是则结束游戏。
6. 轮到另一个玩家继续游戏。

我们还实现了一些辅助方法：

- `printBoard`：打印出当前的棋盘。
- `getValidInput`：从标准输入中获取玩家输入的坐标，并进行合法性检查。
- `checkWin`：检查当前玩家是否获胜。
- `isBoardFull`：检查棋盘是否已满。