MongoDB GeoJSON “Can't extract geo keys from object, malformed geometry?” when inserting type Polygon

问题

I'm getting the error "Can't extract geo keys from object, malformed geometry?". The polygon is closed and the format looks good, as it is inserting correctly into Mongo. I'm using Mongo version 2.6.3, running on Centos 6.5 x64.

What is wrong with the Polygon below? I followed the Mongo examples quite closely.

db.test.remove({});
db.test.insert({testPoly: {type: "Polygon", coordinates: [[0,0],[0,20],[10,30],[20,20],[20,0],[0,0]]}});
db.test.ensureIndex({testPoly: "2dsphere" });
db.test.find();

/* 0 */
{
    "connectionId" : 2385,
    "err" : "Can't extract geo keys from object, malformed geometry?: { _id: ObjectId('54008301eb55d4628c080370'), testPoly: { type: \"Polygon\", coordinates: [ [ 0.0, 0.0 ], [ 0.0, 20.0 ], [ 10.0, 30.0 ], [ 20.0, 20.0 ], [ 20.0, 0.0 ], [ 0.0, 0.0 ] ] } }",
    "code" : 16755,
    "n" : 0,
    "ok" : 1
}

/* 0 */
{
    "_id" : ObjectId("54008301eb55d4628c080370"),
    "testPoly" : {
        "type" : "Polygon",
        "coordinates" : [ 
            [ 
                0, 
                0
            ], 
            [ 
                0, 
                20
            ], 
            [ 
                10, 
                30
            ], 
            [ 
                20, 
                20
            ], 
            [ 
                20, 
                0
            ], 
            [ 
                0, 
                0
            ]
        ]
    }
}

回答1:

You are missing an array level in the coordinates:

coordinates: [[0,0],[0,20],[10,30],[20,20],[20,0],[0,0]]

Should be:

coordinates: [[[0,0],[0,20],[10,30],[20,20],[20,0],[0,0]]]

See http://geojson.org/geojson-spec.html#id4

来源：https://stackoverflow.com/questions/25569901/mongodb-geojson-cant-extract-geo-keys-from-object-malformed-geometry-when-i