说明：
在阅读本公司源码时发现了一段实现随机选择器的代码，感觉不错，现分享出来。

public class RandomSelector {private final NavigableMap<Integer, Object> map = new TreeMap<>();private Integer total = 0;Random random = new Random();public void addItem(Integer weight, Object item) {if (weight != null && weight > 0) {total += weight;map.put(total, item);}}public Object get() {Integer randomInt = random.nextInt(total);return map.higherEntry(randomInt).getValue();}public static void main(String[] args) {RandomSelector randomSelector = new RandomSelector();randomSelector.addItem(40,"a");randomSelector.addItem(60,"b");int a = 0;int b = 0;for (int i = 0; i < 10000; i++) {Object val = randomSelector.get();if ("a".equals(val)){a++;}else if ("b".equals(val)){b++;}}System.out.println(String.format("a:%s b:%s",a,b));}
}

注意：
代码务必要多敲，就上面这么简单的一段代码，我自己敲错了好多地方。🤣