我正在开发一个应用程序，我想在 map 上显示多个标记。 (标记来自数据库(dynamodb)并且值都在“STRING”中而不是 double )。将所有“纬度和经度”的 double 转换为字符串后，出现 java.lang.NumberFormatException: Invalid double: "n/a"异常，应用程序崩溃。因为在表格中，一纬度显示为“na”。 (如图所示)

我卡住了，不知道如何处理这个空值。我应该放一些支票还是什么？提前致谢

((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMapAsync(new OnMapReadyCallback() {
    @Override
    public void onMapReady(final GoogleMap googleMap) {

        mMap = googleMap;

        final LatLng israel = new LatLng(31.0461, 34.8516);
        googleMap.addMarker(new MarkerOptions().position(israel).title("israel"));
        googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        CameraPosition camPos = new CameraPosition.Builder().target(new LatLng(31.0461, 34.8516)).zoom(8).tilt(70).build();
        CameraUpdate camUpd3 = CameraUpdateFactory.newCameraPosition(camPos);
        googleMap.animateCamera(camUpd3);

        mMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
            @Override
            public void onMapLoaded() {

              DDBExecutor.getInstance().getAllSettlements(mContext, new DDBExecutor.OnResponseListener() {
                  @Override
                  public void onResponse(Object result, String message) {
                      List<SettlementsTable> lstSettlements = new ArrayList<>();
                      lstSettlements.addAll((List<SettlementsTable>) result);
                      for (SettlementsTable table : lstSettlements){
                          mMap.addMarker(new MarkerOptions().position(new LatLng(Double.parseDouble(table.getX()), Double.parseDouble(table.getY()))));
                      }
                     LatLngBounds.Builder builder = new LatLngBounds.Builder();
                      builder.include(israel);
                      LatLngBounds bounds = builder.build();
                      CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, 200);
                      mMap.moveCamera(cu);
                      mMap.animateCamera(CameraUpdateFactory.zoomTo(8), 2000, null);

                      try {
                          KmlLayer kmlLayer = new KmlLayer(googleMap, R.raw.settlements, getApplicationContext());
                          kmlLayer.addLayerToMap();
                          KmlLayer kmlLayer1 = new KmlLayer(googleMap, R.raw.outposts, getApplicationContext());
                          kmlLayer1.addLayerToMap();
                          KmlLayer kmlLayer2 = new KmlLayer(googleMap, R.raw.settlements_in_pal_nghbrhd, getApplicationContext());
                          kmlLayer2.addLayerToMap();

                      } catch (XmlPullParserException e) {
                          e.printStackTrace();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  }
              });

            }
        });

最佳答案

用try catch包围

try {
    mMap.addMarker(new MarkerOptions().position(new 
            LatLng(Double.parseDouble(table.getX()), 
                    Double.parseDouble(table.getY()))));
} catch (NumberFormatException ex){
    //do anything when exception occurs
}

关于java - 在 map 上放置多个标记时获取 Latlng 值的无效双 "n\a"，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46955517/