第一个解决方案是使用java.util.Random类:
imp或t java.util.Random;
Random rand = new Random();
// Obtain a number between [0 - 49].
int n = rand.nextInt(50);
// Add 1 to the result to get a number from the required range
// (i.e., [1 - 50]).
n += 1;
另一个解决方案是使用Math.random():
double random = Math.random() * 49 + 1;
或
int random = (int)(Math.random() * 50 + 1);