用java语言写一个二维数组输出星号矩阵

以下是用Java语言编写的输出星号矩阵的代码：

public class StarMatrix {
    public static void main(String[] args) {
        int[][] matrix = new int[5][5];
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[i].length; j++) {
                matrix[i][j] = 1;
            }
        }
        for (int i = 1; i < matrix.length - 1; i++) {
            for (int j = 1; j < matrix[i].length - 1; j++) {
                matrix[i][j] = 0;
            }
        }
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[i].length; j++) {
                if (matrix[i][j] == 1) {
                    System.out.print("* ");
                } else {
                    System.out.print("  ");
                }
            }
            System.out.println();
        }
    }
}

输出结果如下：

* * * * * 
*     * 
*     * 
*     * 
* * * * *