public class Room {

    private String guestName;

    private int id;

    public String getGuestName() {
        return guestName;
    }

    public void setGuestName(String guestName) {
        this.guestName = guestName;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

}



public class Hotel {

    private String name;
    private String address;
    public static int m = 10;
    public static int n = 5;
    private Room[][] rooms;

    public Hotel(String name, String address) {
        super();
        this.name = name;
        this.address = address;
        this.rooms = new Room[m][n];
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                rooms[i][j].setGuestName("EMPTY");
                rooms[i][j].setId(i * 100 + j);
            }
        }
    }
}

------解决方案--------------------
语法来说。。当然可以那么写。。。毋庸置疑！！！

------解决方案--------------------
对的。。。做初始化嘛