如何在我的代码中插入计时器？我的目标是知道我的迷宫生成需要多长时间，因为我将它与之前的论文进行比较。
感谢您的大力帮助。 ：）
以下是我使用的代码：
public class Maze extends JPanel {
private Room[][] rooms;// m x n matrix of rooms
private ArrayList<Wall> walls; // List of walls
private Random rand;// for random wall
private int height;// height of matrix
private int width;// width of matrix
private int num;// incrementor
private JoinRoom ds;// union paths
// paint methods //
private int x_cord; // x-axis rep
private int y_cord;// y-axis rep
private int roomSize;
private int randomWall;
public Maze(int height, int width) {
this.height = height;
this.width = width;
rooms = new Room[height][width];
walls = new ArrayList<Wall>((height - 1) * (width - 1));
generateRandomMaze();
setPreferredSize(new Dimension(800, 700));
}
private void generateRandomMaze() {
generateInitialRooms();// see next method
ds = new JoinRoom(width * height);
rand = new Random(); // here is the random room generator
num = width * height;
while (num > 1) {
// when we pick a random wall we want to avoid the borders getting eliminated
randomWall = rand.nextInt(walls.size());
Wall temp = walls.get(randomWall);
// we will pick two rooms randomly
int roomA = temp.currentRoom.y + temp.currentRoom.x * width;
int roomB = temp.nextRoom.y + temp.nextRoom.x * width;
// check roomA and roomB to see if they are already members
if (ds.find(roomA) != ds.find(roomB)) {
walls.remove(randomWall);
ds.unionRooms(ds.find(roomA), ds.find(roomB));
temp.isGone = true;
temp.currentRoom.adj.add(temp.nextRoom);
temp.nextRoom.adj.add(temp.currentRoom);
num--;
}// end of if
}// end of while
}
// name the room to display
private int roomNumber = 0;
/**
* Sets the grid of rooms to be initially boxes
* This is self explanitory, we are only creating an reverse L for all
* The rooms and there is an L for the border
*/
private void generateInitialRooms() {
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
// create north walls
rooms[i][j] = new Room(i, j);
if (i == 0) {
rooms[i][j].north = new Wall(rooms[i][j]);
} else {
rooms[i][j].north = new Wall(rooms[i - 1][j], rooms[i][j]);
walls.add(rooms[i][j].north);
}
if (i == height - 1) {
rooms[i][j].south = new Wall(rooms[i][j]);
}
if (j == 0) {
rooms[i][j].west = new Wall(rooms[i][j]);
} else {
rooms[i][j].west = new Wall(rooms[i][j - 1], rooms[i][j]);
walls.add(rooms[i][j].west);
}
if (j == width - 1) {
rooms[i][j].east = new Wall(rooms[i][j]);
}
rooms[i][j].roomName = roomNumber++;// we will name the rooms
}
}
// initalize entrance and exit
rooms[0][0].west.isGone = true;// you can replace .west.isGone with .north.isGone
// this is just saying the roomName for top left is 0
rooms[0][0].roomName = 0;
// we will remove the south wall of the last room
rooms[height - 1][width - 1].south.isGone = true;
// this is just saying the roomName for bottom right is the last element in the mxn room matrix
rooms[height - 1][width - 1].roomName = (height * width);
}
public void paintComponent(Graphics g) {
x_cord = 40;
y_cord = 40;
// could have taken height as well as width
// just need something to base the roomsize
roomSize = (width - x_cord) / width + 7;
// temp variables used for painting
int x = x_cord;
int y = y_cord;
for (int i = 0; i <= height - 1; i++) {
for (int j = 0; j <= width - 1; j++) {
if (!(rooms[i][j].north.isGone)) {
g.drawLine(x, y, x + roomSize, y);
}//end of north if
// west wall not there draw the line
if (rooms[i][j].west.isGone == false) {
g.drawLine(x, y, x, y + roomSize);
}// end of west if
if ((i == height - 1) && rooms[i][j].south.isGone == false) {
g.drawLine(x, y + roomSize, x + roomSize,
y + roomSize);
}// end of south if
if ((j == width - 1) && rooms[i][j].east.isGone == false) {
g.drawLine(x + roomSize, y, x + roomSize,
y + roomSize);
}// end of east if
x += roomSize;// change the horizontal
}// end of inner for loop
x = x_cord;
y += roomSize;
}// end of outer for loop
}
public static void main(String[] args) {
// we will use the scanner for userInput
Scanner userInput = new Scanner(System.in);
int m, n;// these are variables for the size of maze (m x n)
System.out.print("Enter the size of your maze: ");
// store the input
m = userInput.nextInt();
n = userInput.nextInt();
// use JFrame to put the created panel on
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 800);
frame.getContentPane().add(new Maze(m, n));
frame.pack();
frame.setVisible(true);
}// end of main
}// END OF CLASS
答案 0 :(得分：1)
我曾写过一个Timer类来执行此操作，您可以在此处找到它：https://github.com/twothe/newdawn/blob/master/two/newdawn/util/TimeCounter.java
对于大多数任务来说，它非常简单和充分。
Java的一般困难是代码不会在恒定时间执行。垃圾收集器之间的某处可能会中断您的计时，或者JIT认为一段代码会减慢并突然优化它。所有这些事情都会弄乱用System.nanoTime()进行的任何测量，所以不要将数字视为事实，而是将其作为一种趋势。
如果你想拥有确切的数字，你需要使用更复杂的工具，特别是运行有问题的代码一千或几十万次以排除背景噪音，但即使这样，这些数字只对你的本地机器有效，在不同的硬件上可能完全不同。
答案 1 :(得分：-1)
这取决于您想要的信息。最简单的方法是在开始生成之前使用System.currentTimeInMillis（），然后再使用System.currentTimeInMillis（）并比较结果。这将为您提供生成的ms数。
e.g。
walls = new ArrayList<Wall>((height - 1) * (width - 1));
long startTime = System.currentTimeMillis();
generateRandomMaze();
long endTime = System.currentTimeMillis();
System.out.println("Time Taken: " + (endTime-startTime) + "ms");
setPreferredSize(new Dimension(800, 700));