javascript - 如何从JSP获取数据到js

Question

我有一个问题，我想知道有人可以帮助我。结果我想制作一些带有不同 GPS 轨迹的小 map 。但我在获取数据时遇到问题。我需要从服务器获取 GPS 轨迹。然后提取属于该轨迹的所有点的坐标并将该数据放入js(在 map 上)中。我会展示出来: 这里我有一个 Controller :

@Controller
public class TracksGeopointsController {

    @Autowired
    private IndexGeopointsService indexGeopointsService;
    @Autowired
    private TracksGeopointsService tracksGeopointsService;
    @Autowired
    private FileService fileService;
    @Autowired
    private MySaxParser mySaxParser;

    @RequestMapping(value = TracksGeopointsRoutes.TRACKS, method = RequestMethod.GET)
    public String tracks(Model model){

        List<TracksGeopointsDoc> tracks = tracksGeopointsService.findAllTracks();
        Map<ObjectId, List<DotGeopointsDoc>> dotsMap = new HashMap<ObjectId, List<DotGeopointsDoc>>();
        for (TracksGeopointsDoc track : tracks){

            try {
                List<DotGeopointsDoc> dots = tracksGeopointsService.getAllTrackDots(track.getId());
                dotsMap.put(track.getId(), dots);
                model.addAttribute("dotsMap", dotsMap); //here I put data to a model to transport it to JSP
                model.addAttribute("tracks", tracks); //here I put data to a model to transport it to JSP
            } catch (TrackNotExistException e) {
                e.printStackTrace();
            }

        }

        Breadcrumbs breadcrumbs = indexGeopointsService.breadcrumbs();
        breadcrumbs.setCurrentPageTitle("GPS треки");

        model.addAttribute("breadcrumbs", breadcrumbs);

        return "com.ub.geopoints_test.tracks";

    }
}

我的 JSP 看起来像这样:

<div class="row">
    <div class="col-md-12">
        <c:forEach var="track" items="${tracks}" varStatus="count"> //I know how to extract data from model above - ${tracks}
            <script>
                var map = L.map('map');
                // create the tile layer with correct attribution
                var osmUrl='http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png';
                var osmAttrib='Map data © <a href="http://openstreetmap.org">OpenStreetMap</a> contributors';
                var osm = new L.TileLayer(osmUrl, {minZoom: 1, maxZoom: 12, attribution: osmAttrib});

                map.addLayer(osm);
                L.Routing.control({
                 waypoints: [

                 L.latLng(57.74, 11.94), // here I want to put data that I gave to model. If it was not js, I'll do this: L.latLng(${dotsMap.get(track.id).lat}, ${dotsMap.get(track.id).lat}) But I don't know how can I do it with js
                 L.latLng(57.6792, 11.949),
                 L.latLng(57.65, 11.888)
                 ]
                 }).addTo(map);
            </script>
        </c:forEach>
    </div>
</div>

拜托，谁能帮帮我。我真的不知道该怎么办。

Answer 1

在同一个jsp页面中，如果您编写js代码，您可以将模型值存储在java脚本变量中。 例如:

var varName = ${modelName.variableName}

因此您可以在同一个 jsp 中的 javascript 代码块中呈现任何模型值。