尝试将 OrmliteForeignCollection与以下类一起使用时遇到问题。我相信我的 Run & Waypoint 类已正确注释。（Run 有一组 WayPoints）。但是，当我尝试访问 WayPoints（请参阅第三个代码摘录）CloseableIterator时，当我调用hasNext(). 当我用模拟器测试它时，我首先为 Run 生成一些 WayPoints 并存储它们。然后我尝试通过 Run 实例访问这些 WayPoints。只是为了补全图，这里不转储太多代码，ForeignCollection<WayPoint>通过调用将对象传递给Contender构造函数
run.getWayPoints();
以下是我创建 WayPoint 并将其存储的方式:: - 当 GPSLocation.onLocationChanged() 触发且状态为 GPS_STATE_RUNNING 时，将调用 createWayPoint()。这将实例化一个 WayPoint，设置 lng/lat 值，并将句柄设置为关联的 Run 实例，此时尚未将其自身存储到数据库中。一个 Intent 被发送到另一个类，该类在 GPSLocation.updateWayPointWithElapsedTime() 上回调，其中 WayPoint 最终存储到数据库中。当运行完成时，外部类调用 storeRun() 来存储 Run 实例。我开始怀疑在关联的 Run 实例本身尚未存储时存储 WayPoint 是否是问题的一部分。
** 注意 :: 这些类将不会编译，因为它们被缩减以显示与问题相关的部分。
@DatabaseTable
public class Run {
@DatabaseField(generatedId=true)
private int id;
@DatabaseField(foreign=true,foreignAutoRefresh=true)
private Route route;
@ForeignCollectionField
private ForeignCollection<WayPoint> wayPoints;
@DatabaseField
private Date date;
@DatabaseField
private long time;
public ForeignCollection<WayPoint> getWayPoints() {
return wayPoints;
}
}
@DatabaseTable
public class WayPoint {
@DatabaseField(generatedId=true)
private int id;
@DatabaseField
private int latitude;
@DatabaseField
private int longitude;
@DatabaseField
private int time; // offset
@DatabaseField(foreign=true,foreignAutoRefresh=true)
private Run run;
}
public class Contender implements Comparable<Contender> {
private int accumulatedDistance;
private int interpolatedDistance;
private WayPoint startPoint;
CloseableIterator itr;
private int id;
WayPoint previous;
WayPoint next;
public Contender(ForeignCollection<WayPoint> wayPoints, WayPoint startPoint, int id) {
this.startPoint = startPoint;
this.id = id;
itr = wayPoints.closeableIterator();
if(itr.hasNext()) {
next = (WayPoint)itr.next();
}
else {
Log.e("@@@", "no way points");
}
Log.i("@@@", "wayPoints size is " + wayPoints.size());
}
}
public class GPSLocation extends Service implements LocationListener {
private Run run;
private WayPoint wayPoint;
private int distanceTravelled;
@Override
public void onCreate() {
locationManager = (LocationManager)getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
startLocationUpdates = new ArrayList<Location>();
Log.i(LOGTAG, "GPSLocation Service Running...");
}
public void startRunning() {
setState(GPS_STATE_RUNNING);
startTime = System.currentTimeMillis();
run = new Run();
run.setRoute(route);
run.setDate(new Date());
}
public void storeRun(long elapsedTime) {
// if first run and end point not set then set end point
run.setTime(elapsedTime);
route.addToCumulativeDistance(distanceTravelled);
DatabaseManager.getInstance().storeRun(run);
DatabaseManager.getInstance().updateRoute(route);
resetGlobalState();
}
public void onLocationChanged(Location location) {
previousLocation = currentLocation;
currentLocation = location;
Intent i = null;
boolean startActivity = true;
switch(state)
{
case GPS_STATE_SETTING_START_LOCATION:
startLocationUpdates.add(location);
if(startLocationAccepted())
{
i = new Intent(this, AddRoute.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.setAction("acquired");
}
else
{
startActivity = false; // waiting for more location data
}
break;
case GPS_STATE_READY:
if(!atLocation(ROUTE_START, location, ROUTE_DELIMITER_REQUIRED_PROXIMITY))
{
setState(GPS_STATE_AWAITING_ARRIVAL_AT_START_LOCATION);
i = new Intent(this, Running.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.setAction("proximity_update");
}
break;
case GPS_STATE_AWAITING_ARRIVAL_AT_START_LOCATION:
i = new Intent(this, Running.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
if(atLocation(ROUTE_START, location, ROUTE_DELIMITER_REQUIRED_PROXIMITY))
{
setState(GPS_STATE_READY);
i.setAction("ready");
}
else
{
i.setAction("proximity_update");
}
break;
case GPS_STATE_RUNNING:
createWayPoint(location);
i = new Intent(this, Running.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
if(atLocation(ROUTE_END, location, ROUTE_DELIMITER_REQUIRED_PROXIMITY)
&& (distanceTravelled > ROUTE_DELIMITER_REQUIRED_PROXIMITY))
{
i.setAction("at_end");
}
else
{
i.setAction("update");
}
distanceTravelled += currentLocation.distanceTo(previousLocation);
i.putExtra("distanceTravelled", distanceTravelled);
setState(GPS_STATE_RUNNING_UPDATE);
break;
default:
// error
}
}
private void createWayPoint(Location location) {
wayPoint = new WayPoint();
wayPoint.setLatitude(LocationMath.degreesToMicroDegrees(location.getLatitude()));
wayPoint.setLongitude(LocationMath.degreesToMicroDegrees(location.getLongitude()));
wayPoint.setRun(run);
}
/*
* Now we have the elapsed time from the Running Activity, we can store this WayPoint
*/
public void updateWayPointWithElapsedTime(long elapsedTime) {
// TODO::check the time value is correct
wayPoint.setTimeOffset((int)elapsedTime);
DatabaseManager.getInstance().storeWayPoint(wayPoint);
setState(GPS_STATE_RUNNING);
}
}
来自数据库管理器的摘录 -->
public void storeWayPoint(WayPoint point) {
try {
getHelper().getWayPointDao().create(point);
} catch (SQLException e) {
e.printStackTrace();
}
}
public void storeRun(Run run) {
try {
getHelper().getRunDao().create(run);
} catch (SQLException e) {
e.printStackTrace();
}
}