java如何在安卓 studio中使用open street map在geojson中保存文件？

Question

我需要在geojson中保存我的点，但我不知道如何保存

我已经尝试过使用KML，但我不能，因为我不知道是否需要使用新类

因为我不知道我应该把它放在一个新的班级里还是放在一个新的班级里，它最终总是会出错，我无法解决它，因为缺乏信息和与这个领域的联系，因为我是新来的，请帮助我，这是一份大学工作

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //onde mostra a imagem do mapa
        Context ctx = getApplicationContext();
        Configuration.getInstance().load(ctx, PreferenceManager.getDefaultSharedPreferences(ctx));

        setContentView(R.layout.activity_main);

        //Essa é para poder utilizar as permissões
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        osm = (MapView) findViewById(R.id.mapaId);
        osm.setTileSource(TileSourceFactory.MAPNIK);
        osm.setUseDataConnection(true);
        osm.setMultiTouchControls(true);
        osm.setClickable(true);
        osm.setBuiltInZoomControls(true);

        if (Build.VERSION.SDK_INT >= M) {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.INTERNET) != PackageManager.PERMISSION_GRANTED ||
                    ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                String[] permissoes = {Manifest.permission.INTERNET, Manifest.permission.WRITE_EXTERNAL_STORAGE};
                requestPermissions(permissoes, PERMISSAO_REQUERIDA);
            }
        }

        osm.setMapListener(new MapListener() {
            @Override
            public boolean onScroll(ScrollEvent event) {
                Log.i("Script()", "onScroll ()");
                return true;
            }

            @Override
            public boolean onZoom(ZoomEvent event) {
                Log.i("Script()", "onZoom ()");
                return false;
            }
        });

        mc = (MapController) osm.getController();
        GeoPoint center = new GeoPoint(-5.1251, -38.3640);
        mc.setZoom(14);
        mc.animateTo(center);
        addMarker(center);


        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            // .
            return;
        }
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);

        MapEventsOverlay mapEventsOverlay = new MapEventsOverlay(this, this);
        osm.getOverlays().add(0, mapEventsOverlay);

        // Aqui adiciona a escala do mapa
        ScaleBarOverlay scaleBarOverlay = new ScaleBarOverlay(osm);
        osm.getOverlays().add(scaleBarOverlay);

        kmlDocument = new KmlDocument();
    //    kmlDocument.parseGeoJSON(geoJsonString);

       /* this.mLocationOverlay = new MyLocationNewOverlay(new GpsMyLocationProvider(ctx),osm);
        this.mLocationOverlay.enableMyLocation();
        osm.getOverlays().add(this.mLocationOverlay);*/

        this.mCompassOverlay = new CompassOverlay(this, new InternalCompassOrientationProvider(ctx), osm);
        this.mCompassOverlay.enableCompass();
        osm.getOverlays().add(this.mCompassOverlay);

    }

这是我的代码，我做到了这一点。如何在其中添加GeoJson，是否应该将其放在onCreate中？我应该创建一个新的java文件来部署库，还是从版本6开始，我需要这样做