獲得對象的最大值

Question

我有一個小問題。我從多個Beacon獲取數據，並將其放入一個arrayList中。現在我想要最近的一個應該返回。

ArrayList<Beacon> arrayList = new ArrayList<Beacon>(); 
String beaconName; 

public void addToBeaconInfo(Beacon beacon) { 

    boolean beaconAlreadyInList = false; 
    //arrayList.add(beacon); 
    beaconName = "" + beacon.getId2() + "" + beacon.getId3(); 
    //Log.i("BeaconInfo","addBeacon_beaconName: "+beaconName + " distance" + beacon.getDistance()); 

    int i; 
    for(i = 0; i < arrayList.size(); i++){ 
     Beacon tempBeacon = arrayList.get(i); 

     if(tempBeacon.getId2().equals(beacon.getId2())){ 
      beaconAlreadyInList = true; 
      arrayList.remove(beacon); 

      Log.i("BeaconInfo", "addBeacon_tempBeacon: " + beacon.getId3() + " distance: " + beacon.getDistance()); 
      break; 
     } 
    } 
    if(beaconAlreadyInList == false){ 
     arrayList.add(beacon); 
     Log.i("arrayList","" + beacon.getDistance() + " " + beacon.getBluetoothName()); 
     double maxDistance = beacon.getDistance(); 
     //double a = Collections.max(maxDistance); 
     //Log.i("maxDistance","" + Math.max()); 
    } 
} 

Answer 1

Beacon nearest = null; 
double distance = Double.MAX_VALUE; 
for (Beacon beacon: arrayList){ 
    double maxDistance = beacon.getDistance(); 
    if (maxDistance < distance) { 
    distance = maxDistance; 
    nearest = beacon; 
    } 
}