GeoJson

时间：2018-01-03 20:50:42

参考 ：

1. GeoJSON
2. rfc7946

GeoJson

用于表达地理空间特征的JSON数据。

几何类型（大小写敏感）：

• Point： the "coordinates" member is a single position.
• MultiPoint：the "coordinates" member is an array of positions.
• LineString：the "coordinates" member is an array of two or more positions.
• MultiLineString：the "coordinates" member is an array of LineString coordinate arrays.
• Polygon：闭合，中间可以有孔（多边形嵌套一个多边形，两个多边形之间的内容）
• MultiPolygon：the "coordinates" member is an array of Polygon coordinate arrays.
• GeometryCollection

GeoJson类型，包含上面七个（大小写敏感），以及：

• Feature ：代表空间有限的事物
• FeatureCollection

示例

几何图形（Geometry）

Points 点

Point coordinates are in x, y order (easting, northing for projected coordinates, longitude, and latitude for geographic coordinates):

    {
        "type": "Point",
        "coordinates": [100.0, 0.0]
    }

LineStrings 线，点的集合

Coordinates of LineString are an array of positions.

```json
{
  "type": "LineString",
  "coordinates": [
    [100.0, 0.0],
    [101.0, 1.0]
  ]
}
```

Polygons 多边形

• 无孔多边形：

  json { "type": "Polygon", "coordinates": [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ] ] }

• 嵌套多边形

  json { "type": "Polygon", "coordinates": [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ], [ [100.8, 0.8], [100.8, 0.2], [100.2, 0.2], [100.2, 0.8], [100.8, 0.8] ] ] }

MultiPoints 多个点

```json
 {
     "type": "MultiPoint",
     "coordinates": [
         [100.0, 0.0],
         [101.0, 1.0]
     ]
 }
```

MultiPolygons 多个多边形

```json
{
    "type": "MultiPolygon",
    "coordinates": [
        [
            [
                [102.0, 2.0],
                [103.0, 2.0],
                [103.0, 3.0],
                [102.0, 3.0],
                [102.0, 2.0]
            ]
        ],
        [
            [
                [100.0, 0.0],
                [101.0, 0.0],
                [101.0, 1.0],
                [100.0, 1.0],
                [100.0, 0.0]
            ],
            [
                [100.2, 0.2],
                [100.2, 0.8],
                [100.8, 0.8],
                [100.8, 0.2],
                [100.2, 0.2]
            ]
        ]
    ]
}
```

MultiLineStrings 多条线

```json
 {
     "type": "MultiLineString",
     "coordinates": [
         [
             [100.0, 0.0],
             [101.0, 1.0]
         ],
         [
             [102.0, 2.0],
             [103.0, 3.0]
         ]
     ]
 }
 ```

GeometryCollections 几何图形集合

```json
{
    "type": "GeometryCollection",
    "geometries": [
       {
        "type": "Point",
        "coordinates": [100.0, 0.0]
       },
       {
        "type": "LineString",
        "coordinates": [
            [101.0, 0.0],
            [102.0, 1.0]
        ]
    }]
}
```json

FeatureCollection 特征集合

```json
{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [102.0, 0.5]
      },
      "properties": {
        "prop0": "value0"
      }
    },
    {
      "type": "Feature",
      "geometry": {
        "type": "LineString",
        "coordinates": [
          [102.0, 0.0],
          [103.0, 1.0],
          [104.0, 0.0],
          [105.0, 1.0]
        ]
      },
      "properties": {
        "prop0": "value0",
        "prop1": 0.0
      }
    },
    {
      "type": "Feature",
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [100.0, 0.0],
            [101.0, 0.0],
            [101.0, 1.0],
            [100.0, 1.0],
            [100.0, 0.0]
          ]
        ]
      },
      "properties": {
        "prop0": "value0",
        "prop1": {
          "this": "that"
        }
      }
    }
  ]
}
```