LBS-根据经纬度求距离XXXXXX

雨点打透心脏的1/2处 2021-06-24 16:09 761阅读 0赞

public class DistanceUtil {
        private static final double EARTH_RADIUS = 6378.137;
    
        private static double rad(double d) {
            return d * Math.PI / 180.0;
        }
    
        /**
         * @param long1
         * @param lat1
         * @param long2
         * @param lat2
         * @return 两点距离，单位（千米）
         */
        public static double getDistance(Double long1, Double lat1, Double long2, Double lat2) {
            if (long1 == null || lat1 == null || long2 == null || lat2 == null) return 0;
            double a, b, d, sa2, sb2;
            lat1 = rad(lat1);
            lat2 = rad(lat2);
            a = lat1 - lat2;
            b = rad(long1 - long2);
    
            sa2 = Math.sin(a / 2.0);
            sb2 = Math.sin(b / 2.0);
            d = 2 * EARTH_RADIUS
                    * Math.asin(Math.sqrt(sa2 * sa2 + Math.cos(lat1)
                    * Math.cos(lat2) * sb2 * sb2));
            return d;
        }
    
        public static void main(String[] args) {
            List<Worker> workers = new ArrayList<>();
            workers.add(new Worker(1));
            workers.add(new Worker(2));
            workers.add(new Worker(3));
            workers.add(new Worker(4));
            workers.add(new Worker(5));
            workers.parallelStream().filter(Worker::finish).findFirst().ifPresent(first -> System.out.println("id : " + first.id));
        }
    
        static class Worker {
    
            int id;
    
            Worker(int id) {
                this.id = id;
            }
    
            boolean finish() {
                int t = id * 1000;
                System.out.println(id + " -> " + t);
                try {
                    Thread.sleep(t);
                } catch (InterruptedException ignored) {
                }
                System.out.println(id+" finished");
                return id <= 3;
            }
    
        }
    }