Geofire-找不到位置 [英] Geofire - not found locations
问题描述
如何使用地理位置查询. 我有以下代码(它什么也没有发生):
How can I get the all locations that are near to a passed GeoLocation(double lat, double lng) using Geo Queries.
I have the following code (and it happens nothing):
public void setCurrentLatLng(double lat, double lng){
this.lat = lat;
this.lng = lng;
GeoLocation geoLocation = new GeoLocation(lat, lng);
updateCurrenLocation(geoLocation);
GeoQuery geoQuery = geoFire.queryAtLocation(geoLocation, 8f);
geoQuery.addGeoQueryDataEventListener(new GeoQueryDataEventListener() {
@Override
public void onDataEntered(DataSnapshot dataSnapshot, GeoLocation location) {
Log.d("geoQuery","onDataEntered "+dataSnapshot.toString());
// ...
}
@Override
public void onDataExited(DataSnapshot dataSnapshot) {
Log.d("geoQuery","onDataExited "+dataSnapshot.toString());
// ...
}
@Override
public void onDataMoved(DataSnapshot dataSnapshot, GeoLocation location) {
Log.d("geoQuery","onDataMoved "+dataSnapshot.toString());
// ...
}
@Override
public void onDataChanged(DataSnapshot dataSnapshot, GeoLocation location) {
Log.d("geoQuery","onDataChanged "+dataSnapshot.toString());
// ...
}
@Override
public void onGeoQueryReady() {
// ...
Log.d("geoQuery","onGeoQueryReady");
}
@Override
public void onGeoQueryError(DatabaseError error) {
Log.d("geoQuery","onGeoQueryError");
// ...
}
});
this.setChanged();
notifyObservers();
this.clearChanged();
Log.d("update","clearChanged");
}
这是我的Firebase数据:
And this is my firebase data:
我认为我愿意根据需要修改数据结构.
I think I'm open to modify the data struct if needed.
09-12 08:55:33.818 17710-17710/es.rchampa.weirdo D/geoQuery: lat=40.4430883 lng=-3.721805
09-12 08:55:33.982 17710-17710/es.rchampa.weirdo D/geoQuery: lat=40.4430883 lng=-3.721805
09-12 08:55:33.986 17710-17710/es.rchampa.weirdo D/geoQuery: onGeoQueryReady
09-12 08:55:34.025 17710-17710/es.rchampa.weirdo D/geoQuery: onGeoQueryReady
成绩文件
....
// Firebase
implementation 'com.google.firebase:firebase-database:16.0.1'
implementation 'com.google.firebase:firebase-storage:16.0.1'
implementation 'com.google.firebase:firebase-auth:16.0.3'
implementation 'com.google.firebase:firebase-crash:16.2.0'
implementation 'com.google.firebase:firebase-core:16.0.3'
// Firebase UI
implementation 'com.firebaseui:firebase-ui-database:1.2.0'
//Firebase GeoFire
implementation 'com.firebase:geofire-android:2.3.1'
// Google Play Services
implementation 'com.google.android.gms:play-services-auth:16.0.0'
implementation 'com.google.android.gms:play-services-maps:15.0.1'
implementation 'com.google.android.gms:play-services-location:15.0.1'
....
更新
如果您愿意，我可以授予访问我的私人仓库的权限.
UPDATE
I can grant access to my private repo if you wish.
推荐答案
，您将值8f(float)传递为radius，而radius应该是8.0d或Double.valueOf(8.0)， MAX_SUPPORTED_RADIUS等于8587公里.
you pass value 8f (float) as the radius there, while the the radius should rather be 8.0d or Double.valueOf(8.0), where MAX_SUPPORTED_RADIUS equals 8587 kilometers.
实际的问题是，GeoFire已经需要知道.child("location")，但是不可能用Reference表示.只有DataSnapshot有getChildren().
while the actual problem is, that GeoFire already would need to know of .child("location"), but it is not possible to represent that with a Reference; only DataSnapshot has getChildren().
最重要的是:
您必须创建一个单独的位置
Reference，以避免嵌套.不过，您仍然可以对这些节点使用相关的uid键(或至少将其添加为子节点)，以便能够在用户Reference中进行查找.这是一个1:1关系，介于两个Reference之间.
you'd have to create a separate locations
Reference, in order to avoid the nesting. nevertheless you still can use the relateduidkey for these nodes (or at least add it as a child-node), in order to be able to look up within the usersReference. it's a1:1relation, in between twoReferences.
所以这是一个有效的Java示例，只是因为...
so here's a working Java example, just because ...
我们假设采用以下结构(如上所述):
we're assuming the following structure (as described above):
{
"locations" : {
"CR88aa9gnDfJYYGq5ZTMwwC38C12" : {
".priority" : "9q8yywdgue",
"g" : "9q8yywdgue",
"l" : [ 37.7853889, -122.4056973 ]
}
},
"users" : {
"CR88aa9gnDfJYYGq5ZTMwwC38C12" : {
"displayName" : "user 01",
...
}
}
}
对于locations字段g，数据库规则应具有.indexOn:
the database rules should have .indexOn for locations field g set:
{
"rules": {
...
"locations": {
".indexOn": "g"
}
}
}
模块build.gradle中的依赖项:
dependencies {
...
implementation "com.firebase:geofire-android:2.3.1"
}
这演示了如何通过GeoQuery结果获取用户的快照；
and this demonstrates, how to obtain a user's snapshot by a GeoQuery result;
注意GeoQueryEventListener而不是GeoQueryDataEventListener:
public class GeofireActivity extends AppCompatActivity {
private static final String LOG_TAG = GeofireActivity.class.getSimpleName();
private DatabaseReference refBase = null;
private DatabaseReference refLocation = null;
private DatabaseReference refUser = null;
private GeoFire geoFire = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.fragment_geofire);
this.setReferences();
}
private void setReferences() {
this.refBase = FirebaseDatabase.getInstance().getReference();
this.refUser = refBase.child("users");
this.refLocation = refBase.child("locations");
this.geoFire = new GeoFire(this.refLocation);
}
private void searchNearby(double latitude, double longitude, double radius) {
this.searchNearby(new GeoLocation(latitude, longitude), radius);
}
private void searchNearby(GeoLocation location, double radius) {
GeoQuery geoQuery = this.geoFire.queryAtLocation(location, radius);
geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
@Override
public void onKeyEntered(String key, GeoLocation location) {
String loc = String.valueOf(location.latitude) + ", " + String.valueOf(location.longitude);
Log.d(LOG_TAG, "onKeyEntered: " + key + " @ " + loc);
/* once the key is known, one can lookup the associated record */
refUser.child(key).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
Log.d(LOG_TAG, "onDataChange: " + dataSnapshot.toString());
}
@Override
public void onCancelled(@NonNull DatabaseError firebaseError) {
Log.e(LOG_TAG, "onCancelled: " + firebaseError.getMessage());
}
});
}
@Override
public void onKeyExited(String key) {
Log.d(LOG_TAG, "onKeyExited: " + key);
}
@Override
public void onKeyMoved(String key, GeoLocation location) {
Log.d(LOG_TAG, "onKeyMoved: " + key);
}
@Override
public void onGeoQueryReady() {
Log.d(LOG_TAG, "onGeoQueryReady");
}
@Override
public void onGeoQueryError(DatabaseError error) {
Log.e(LOG_TAG, "onGeoQueryError" + error.getMessage());
}
});
}
}
为了维护完整性，当删除用户记录时，需要删除关联的位置记录-否则将导致键，无法再查找.
in order to maintain the integrity, one would need to remove the associated location record, when a user record is being removed - else it would result in keys, which cannot be looked up anymore.
这篇关于Geofire-找不到位置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
