Android 获取JSON数据后如何向mapView添加多个管脚

我正在制作一个应用程序来显示最近的五个地铁站。我能够获取站点的名称，并用数据填充列表视图

我正在从API获取lng和lat，并希望使用这些坐标向地图添加管脚。我已经让地图工作，我可以显示一个引脚，但不能显示多个引脚。如果您能指出正确的方向，我们将不胜感激-请参阅下面的代码

public class nearMe extends AppCompatActivity implements OnMapReadyCallback {

    private MapView mapView;
    public GoogleMap gmap;
    private static final String MAP_VIEW_BUNDLE_KEY = "MapViewBundleKey";

    // Location Co-ordinates
    private String lat = "";
    private String lng = "";

    LocationManager locationManager;
    LocationListener locationListener;

    private List<Station> stationList = new ArrayList<>();
    private RecyclerView recyclerView;
    private stationAdapter mAdapter;

    /*   LOCATION STUFF     */
    @Override
    public void onRequestPermissionsResult(int requestCode,  String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

            startListening();
        }
    }

    public void startListening() {

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

            locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        }
    }

    public void updateLocationInfo(Location location) {
        lat = "" + location.getLatitude();
        lng = "" + location.getLongitude();
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_location, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
      //  int id = item.getItemId();


        getNearestStations();
        Toast.makeText(this, "Location Updated!", Toast.LENGTH_SHORT).show();

        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_near_me);
        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);

        mAdapter = new stationAdapter(stationList);
        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);

// onClick
        recyclerView.addOnItemTouchListener(new TouchListener(getApplicationContext(), recyclerView, new ClickListener() {
            @Override
            public void onClick(View view, int position) {
              // Toast.makeText(getApplicationContext(), stationList.get(position).getStation() + "", Toast.LENGTH_SHORT).show();

                String findStation = stationList.get(position).getStation();

              //  Toast.makeText(nearMe.this, bob, Toast.LENGTH_SHORT).show();

                Uri gmmIntentUri = Uri.parse("google.navigation:q="+findStation+"underground station+London&mode=w");
                Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
                mapIntent.setPackage("com.google.android.apps.maps");
                mapIntent.setFlags(mapIntent.FLAG_ACTIVITY_CLEAR_TOP);
                if (mapIntent.resolveActivity(getPackageManager()) != null) {
                    startActivity(mapIntent);
                }
            }


        }));

        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                updateLocationInfo(location);
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {
            }

            @Override
            public void onProviderEnabled(String provider) {
            }

            @Override
            public void onProviderDisabled(String provider) {
            }
        };

        if (Build.VERSION.SDK_INT < 23) {
            startListening();
        } else {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
            } else {
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
                Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

                if (location != null) {
                    updateLocationInfo(location);
                }
            }
        }

        // insert Stations in to recycler
        getNearestStations();

        //map
        Bundle mapViewBundle = null;
        if (savedInstanceState != null) {
            mapViewBundle = savedInstanceState.getBundle(MAP_VIEW_BUNDLE_KEY);
        }

        mapView = (MapView) findViewById(R.id.map_view);
        mapView.onCreate(mapViewBundle);
        mapView.getMapAsync(this);
    }

    // clear adapter before adding
    public void clear() {
        int size = this.stationList.size();
        this.stationList.clear();
        mAdapter.notifyItemRangeRemoved(0, size);
    }

    public void getNearestStations(){

        RequestQueue queue = Volley.newRequestQueue(this);
        String url = "https://transportapi.com/v3/uk/tube/stations/near.json?app_id=157c4895&app_key=091697cea8bae89519dd02ebb318fc51&lat=" + lat + "&lon=" + lng + "&rpp=5";

        final StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
                    JSONObject jsonObject = new JSONObject(response);
                    JSONArray jsonArray = jsonObject.getJSONArray("stations");

                    // Call 'Clear' method to clear mAdapter before adding new data
                    clear();
                    if (jsonArray.length() > 0) {

                        for (int i = 0; i < jsonArray.length(); i++) {
                            JSONObject jObject = jsonArray.getJSONObject(i);

                            String station = jObject.getString("name");

                            Station newStation = new Station(station);
                            stationList.add(newStation);

                            mAdapter.notifyDataSetChanged();

                            double longitude = Double.parseDouble(lng);
                            double latitude = Double.parseDouble(lat);
                            gmap.addMarker(new MarkerOptions()
                                    .position(new LatLng(latitude, longitude))
                                    .title(station));

                        }
                    }else{
                        Station newStation = new Station("No stations near");
                        stationList.add(newStation);
                        mAdapter.notifyDataSetChanged();

                        // Show a diaog
                        AlertDialog alertDialog = new AlertDialog.Builder(nearMe.this).create();
                        alertDialog.setTitle("No Stations Found");
                        alertDialog.setMessage("You are either not in London or you have no network connectivity.");
                        alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                                new DialogInterface.OnClickListener() {
                                    public void onClick(DialogInterface dialog, int which) {
                                        dialog.dismiss();
                                    }
                                }); alertDialog.show();
                    }
                } catch (JSONException e) { }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
            }
        });
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        requestQueue.add(stringRequest);
    }
// maps

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        Bundle mapViewBundle = outState.getBundle(MAP_VIEW_BUNDLE_KEY);
        if (mapViewBundle == null) {
            mapViewBundle = new Bundle();
            outState.putBundle(MAP_VIEW_BUNDLE_KEY, mapViewBundle);
        }
        mapView.onSaveInstanceState(mapViewBundle);
    }
    @Override
    protected void onResume() {
        super.onResume();
        mapView.onResume();
    }

    @Override
    protected void onStart() {
        super.onStart();
        mapView.onStart();
    }

    @Override
    protected void onStop() {
        super.onStop();
        mapView.onStop();
    }
    @Override
    protected void onPause() {
        mapView.onPause();
        super.onPause();
    }
    @Override
    protected void onDestroy() {
        mapView.onDestroy();
        super.onDestroy();
    }
    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mapView.onLowMemory();
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {




    }
}

public类nearMe扩展了AppCompatActivity在MapReadyCallback上的实现{
私有地图视图；
谷歌地图gmap；
私有静态最终字符串MAP\u VIEW\u BUNDLE\u KEY=“MapViewBundleKey”；
//位置坐标
私有字符串lat=“”；
私有字符串lng=“”；
地点经理地点经理；
LocationListener LocationListener；
private List stationList=new ArrayList（）；
私人回收站；
私人车站适配器；
/*位置信息*/
@凌驾
public void onRequestPermissionsResult（int-requestCode、字符串[]权限、int[]grantResults）{
super.onRequestPermissionsResult（请求代码、权限、授权结果）；
if（grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION\u已授予）{
惊人的倾听（）；
}
}
公营机构{
if（ContextCompat.checkSelfPermission（此，Manifest.permission.ACCESS\u FINE\u位置）==PackageManager.permission\u已授予）{
locationManager=（locationManager）this.getSystemService（Context.LOCATION\u服务）；
}
}
公共void updateLocationInfo（位置）{
lat=”“+位置。getLatitude（）；
lng=”“+location.getLongitude（）；
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
//为菜单充气；这会将项目添加到操作栏（如果存在）。
getMenuInflater（）.充气（右菜单菜单位置，菜单）；
返回true；
}
@凌驾
公共布尔值onOptionsItemSelected（菜单项项）{
//int id=item.getItemId（）；
获取最近的站点（）；
Toast.makeText（此“位置已更新！”，Toast.LENGTH_SHORT.show（）；
返回super.onOptionsItemSelected（项目）；
}
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u near\u me）；
recyclerView=（recyclerView）findViewById（R.id.recycler\u视图）；
mAdapter=新stationAdapter（stationList）；
RecyclerView.LayoutManager mLayoutManager=新的LinearLayoutManager（getApplicationContext（））；
recyclerView.setLayoutManager（mLayoutManager）；
setItemAnimator（新的DefaultItemAnimator（））；
recyclerView.setAdapter（mAdapter）；
//onClick
addOnItemTouchListener（新的TouchListener（getApplicationContext（），recyclerView，新的ClickListener（））{
@凌驾
公共void onClick（视图，int位置）{
//Toast.makeText（getApplicationContext（），stationList.get（position）.getStation（）+“”，Toast.LENGTH_SHORT）.show（）；
String findStation=stationList.get（位置）.getStation（）；
//Toast.makeText（nearMe.this，bob，Toast.LENGTH_SHORT）.show（）；
Uri gmmIntentUri=Uri.parse（“google.navigation:q=“+findStation+”地铁站+London&mode=w”）；
Intent mapIntent=新的Intent（Intent.ACTION\u视图，gmminentUri）；
setPackage（“com.google.android.apps.maps”）；
mapIntent.setFlags（mapIntent.FLAG\u活动\u清除\u顶部）；
if（mapIntent.RESOLVECTIVITY（getPackageManager（））！=null）{
星触觉（mapIntent）；
}
}
}));
locationManager=（locationManager）this.getSystemService（Context.LOCATION\u服务）；
locationListener=新locationListener（）{
@凌驾
已更改位置上的公共无效（位置）{
updateLocationInfo（位置）；
}
@凌驾
public void onStatusChanged（字符串提供程序、int状态、Bundle extra）{
}
@凌驾
公共无效onProviderEnabled（字符串提供程序）{
}
@凌驾
公共无效onProviderDisabled（字符串提供程序）{
}
};
如果（Build.VERSION.SDK_INT<23）{
惊人的倾听（）；
}否则{
if（ContextCompat.checkSelfPermission（this，Manifest.permission.ACCESS\u FINE\u LOCATION）！=PackageManager.permission\u已授予）{
ActivityCompat.requestPermissions（这个新字符串[]{Manifest.permission.ACCESS\u FINE\u LOCATION}，1）；
}否则{
locationManager.RequestLocationUpdate（locationManager.GPS\提供程序，0，0，locationListener）；
Location Location=locationManager.getLastKnownLocation（locationManager.GPS\U提供程序）；
如果（位置！=null）{
updateLocationInfo（位置）；
}
}
}
//将站点插入到回收站
获取最近的站点（）；
//地图
Bundle mapViewBundle=null；
如果（savedInstanceState！=null）{
mapViewBundle=savedInstanceState.getBundle（映射视图绑定键）；
}
mapView=（mapView）findViewById（R.id.map\u视图）；
onCreate（mapViewBundle）；
getMapAsync（这个）；
}
//添加前清除适配器
公共空间清除（）{
int size=this.stationList.size（）；
this.stationList.clear（）；
mAdapter.notifyItemRangeRemoved（0，大小）；
}
公共无效getNearestStations（）{
RequestQueue=Volley.newRequestQueue（this）；
字符串url=”https://transportapi.com/v3/uk/tube/stations/near.json?app_id=157c4895&app_key=091697cea8bae895
for(int i = 0 ; i < markers.size() ; i++ ) {

    createMarker(markers.get(i).getLatitude(), markers.get(i).getLongitude(), markers.get(i).getTitle(), markers.get(i).getSnippet(), markers.get(i).getIconResID());
}

...

protected Marker createMarker(double latitude, double longitude, String title, String snippet, int iconResID) {

    return googleMap.addMarker(new MarkerOptions()
            .position(new LatLng(latitude, longitude))
            .anchor(0.5f, 0.5f)
            .title(title)
            .snippet(snippet);
            .icon(BitmapDescriptorFactory.fromResource(iconResID)));
}