请求实体太大-谷歌地图方向错误413

由于没有人能帮我解决问题，我不得不自己解决。我在回答我自己的问题，因为这对很多人来说似乎是一个很大的问题，而且在网上解释得不够好，所以这可能会帮助有类似问题的开发人员。

不管怎样，让我们开门见山。正如OxyDesign所建议的，由于谷歌的限制，该错误被抛出，错误为：

• google.maps.DirectionsResult.MAX_WAYPOINTS_EXCEEDED-这是因为我发送了一个包含起点、目的地和超过8个（谷歌限制）路点的请求

我很容易就解决了（我只是把数组分成10个点的块，把一个请求的最后一个点作为下一个的第一个点），但后来我得到了另一个错误：

• google.maps.DirectionsResult.OVER_QUERY_LIMIT-这是因为我试图每秒发送超过10个（同样是谷歌限制）请求

这需要更多的实验、搜索和测试才能解决，但我解决了。

现在，这是对我有效的代码（至少在发布时，直到谷歌改变一些东西）：

// list of randomly generated locations (max 288)
var locations = [];
for(var i=0; i<288; i++){
    locations[i] = {
        datetime: '2014/10/01 12:10',
        location: (51 + Math.random()) +
        ' ' + (-0.5 + Math.random()) + ' 30.0'
    };
}
// Marker images
var image_pin = new google.maps.MarkerImage(
    'http://stedkomerc.com.mk/gpslocator/images/mPin.svg',  
    new google.maps.Size(25, 41),  // size
    new google.maps.Point(0, 0),   // origin, top-left corner
    new google.maps.Point(12, 40)  // anchor
);
var image_circle = new google.maps.MarkerImage(
    'http://stedkomerc.com.mk/gpslocator/images/mCircle.svg',
    new google.maps.Size(19, 19),  // size
    new google.maps.Point(0, 0),   // origin, top-left corner
    new google.maps.Point(9, 9)    // anchor
);
// Variables
var map;
var bounds = new google.maps.LatLngBounds();
var markers = [];
var pathPoints = [];
var geocoder;
var infoWindow = new google.maps.InfoWindow();
var accuracy = new google.maps.Circle({
    fillColor: '#ff4080',
    fillOpacity: 0.4,
    strokeOpacity: 0,
    zIndex: 0
});
var polyOptions = {
    geodesic: true,
    strokeColor: '#28b8b8',
    strokeOpacity: 1.0,
    strokeWeight: 8,
    zIndex: 1
};
var path = new google.maps.Polyline(polyOptions);
var directionsService = new google.maps.DirectionsService();
var directions = [];
var rendererOptions = {
    draggable: false,
    hideRouteList: true,
    suppressMarkers: true,
    preserveViewport: true,
    infoWindow: infoWindow,
    polylineOptions: polyOptions
};
var requests = [];
var MAX_POINTS_PER_REQUEST = 10; // 8*waypts Google limit + start + end
var MAX_REQUESTS_PER_SECOND = 10; // Google limit
// functions
function showInfoWindow(marker, datetime, acc){
    geocoder = new google.maps.Geocoder();
    geocoder.geocode({
        'latLng': marker.getPosition()
    }, function(results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            if (results[1]) {
                infoWindow.close();
                var date = datetime.split(" ")[0];
                var time = datetime.split(" ")[1];
                var content = '<div class="infowindow">' +
                    results[1].formatted_address.trim() + '<br />' +
                    'Date: ' + date + '<br />' +
                    'Time: ' + time + '<br />' +
                    'Accuracy: ' + acc + 'm' +
                    '</div>';
                infoWindow.setContent(content);
                infoWindow.open(map, marker);
                accuracy.setMap(null);
                accuracy.setMap(map);
                accuracy.setCenter(marker.getPosition());
                accuracy.setRadius(acc);
            }
        } else {
            console.log('Geocoder failed due to: ' + status);
        }
    });
}
function addMultiMarker(latLng, num, datetime, acc){
    // Create marker at provided location
    var marker = new google.maps.Marker({
        position: latLng,
        map: map,
        icon: image_circle,
        title: 'Location #' + num,
        zIndex: num + 1
    });
    // On marker click center it inside map and show infoWindow
    google.maps.event.addListener(marker, 'click', function() {
        //map.panTo(marker.getPosition());
        showInfoWindow(marker, datetime, acc);
    });
    return marker;
}
function connectMarkersPolyline(mrkrs){
    path.setMap(map);
    pathPoints = path.getPath();
    len = mrkrs.length;
    for(var i = 0; i < len; i++){
        pathPoints.push(mrkrs[i].getPosition());
    }
}
function connectMarkersRoute(mrkrs, part, maxParts){
    var directionsDisplay = new google.maps.DirectionsRenderer(rendererOptions);
    directionsDisplay.setMap(map);
    var len = mrkrs.length;
    var start = mrkrs[0].getPosition();
    var end = mrkrs[len - 1].getPosition();
    var wayPts = [];
    for(var i = 1; i < len - 1; i++){
        wayPts.push({
            location: mrkrs[i].getPosition(),
            stopover: true
        });
    }
    var request = {
        origin: start,
        destination: end,
        waypoints: wayPts,
        optimizeWaypoints: false,
        travelMode: google.maps.TravelMode.DRIVING,
        unitSystem: google.maps.UnitSystem.METRIC
    };
    directionsService.route(request, function(response, status) {
        if (status == google.maps.DirectionsStatus.OK) {
            // request status OK, display route
            directionsDisplay.setDirections(response);
            // save it in array in case we want to remove it later
            directions.push(directionsDisplay);
            // if not last chunk, send next chunk after 100ms
            // 1 request per 100ms => 10 requests per 1s
            if(part+1 < maxParts)
                setTimeout(connectMarkersRoute(requests[part+1], part+1, maxParts), 100);
            else showLastMarker();
        } else if (status == google.maps.DirectionsStatus.OVER_QUERY_LIMIT) {
            // if we get error, send same request after bigger delay (120ms)
            setTimeout(connectMarkersRoute(requests[part], part, maxParts), 120);
        } else {
            // if all fails, connect with simple polyline
            console.log('Directions failed due to: ' + status);
            connectMarkersPolyline(mrkrs);
        }
    });
}
function connectMarkers(markers){
    path.setMap(null);
    path.setPath([]);
    directions = [];
    requests = [];
    var len = markers.length;
    console.log('connecting ' + len + ' markers');
    var i, j;
    // split markers array into chunks of 10 (start + waypts + end)
    for(i=0; i<len; i+=MAX_POINTS_PER_REQUEST-1){
        if(i<len-1)
            requests.push(markers.slice(i, i+MAX_POINTS_PER_REQUEST));
    }
    // send first chunk to connectMarkersRoute()
    connectMarkersRoute(requests[0], 0, requests.length);
}
function showMapPeriod(periodStart, periodEnd){
    // Map options
    var mapOptions = {
        zoom: 16,
        center: new google.maps.LatLng(41.995922, 21.431465),
        mapTypeId : google.maps.MapTypeId.ROADMAP,
        mapTypeControl: true,
        mapTypeControlOptions: {
            style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR,
            position: google.maps.ControlPosition.TOP_RIGHT
        },
        zoomControl: true,
        zoomControlOptions: {
            style: google.maps.ZoomControlStyle.LARGE,
            position: google.maps.ControlPosition.LEFT_CENTER
        },
        panControl: false,
        streetViewControl: false
    };
    $("#map").html("");
    //openMapContainer();
    // Create and show map
    map = new google.maps.Map(document.getElementById('map'), mapOptions);
    // Create and display markers
    bounds = new google.maps.LatLngBounds();
    markers = [];
    var len = 0;
    for(var i = periodStart; i <= periodEnd; i++, len++){
        var loc_vals = locations[i].location.trim().split(" ");
        var lat = parseFloat(loc_vals[0]);
        var lng = parseFloat(loc_vals[1]);
        var acc = parseFloat(loc_vals[2]);
        // Create marker at provided location
        var datetime = locations[i].datetime;
        var latLng = new google.maps.LatLng(lat, lng);
        markers[len] = addMultiMarker(latLng, len+1, datetime, acc);
        bounds.extend(latLng);
    }
    connectMarkers(markers);
    map.fitBounds(bounds);
    if(map.getZoom() > 16) map.setZoom(16);  
}
function showLastMarker(){
    new google.maps.event.trigger(markers[markers.length - 1], 'click');  
}
// show map
showMapPeriod(1, 280);
// --------

正如您所看到的，我所做的唯一真正的更改是showRoute()函数变成了connectMarkers()，与处理这两个错误的connectMarkersRoute()和connectMarkersPolyline()相结合。

这里可以看到工作示例。加载所有路由块需要一点时间，但至少它可以工作。希望这也能帮助其他人。

请注意，谷歌每天有2500个Directions请求的限制，所以要小心。话虽如此，这个答案即使适用于200多个地点的更大请求，我已经测试了1250个地点，它也有效。

这项服务Gmaps Waypoints似乎有局限性（8或23，我试过了，它一直工作到39，然后40没有），除了多段线之外，没有其他方法可以实现它，但你不想要它，所以我认为没有可行的解决方案。。。