geojson数据示例，以及常用的数据来源

1、标准的geojson数据（如下：点数据、线数据、面数据）

{
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "properties": {},
            "geometry": {
                "type": "Point",
                "coordinates": [
                    108.93871307373047,
                    34.261756524459805
                ]
            }
        },
        {
            "type": "Feature",
            "properties": {},
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [
                        108.94197463989258,
                        34.22741608114276
                    ],
                    [
                        108.94248962402342,
                        34.311964819565006
                    ]
                ]
            }
        },
        {
            "type": "Feature",
            "properties": {},
            "geometry": {
                "type": "Polygon",
                "coordinates": [
                    [
                        [
                            108.92000198364258,
                            34.25352744692606
                        ],
                        [
                            108.96806716918945,
                            34.25352744692606
                        ],
                        [
                            108.96806716918945,
                            34.2777867255175
                        ],
                        [
                            108.92000198364258,
                            34.2777867255175
                        ],
                        [
                            108.92000198364258,
                            34.25352744692606
                        ]
                    ]
                ]
            }
        }
    ]
}