从特定单词开始从 geojson 读取

Question

我知道这里已经提到了这个问题：

Start reading the file after a specific word

但是，就我而言，我想从特定单词（包括该单词）读取 .geojson 文件并将其保存在字符串中。

{"type": "FeatureCollection","features": [{"type": "Feature","properties": {},"geometry": {"type": "LineString","coordinates": [[4.354282,52.032195],[4.354087,52.032462],[4.353783,52.032962],[4.353579,52.033437],[4.353333,52.034151],[4.352991,52.03545],[4.352517,52.037002],[4.352442,52.037352],[4.352368,52.0378],[4.352336,52.038238],[4.352331,52.039962],[4.352346,52.040706]
        ]
      }
    }
  ]
}

我的字符串应以 {"type": "Linestring" 开头，然后是文件的其余部分。它必须适用于任何 Linestring geojson。

到目前为止我的代码：

BufferedReader br = new BufferedReader(new FileReader(
                "C:\Users\****\Desktop\test2.geojson"));
        String line;
        while ((line = br.readLine()) != null) {
            if (line.contains("LineString")) {

                break; // breaks the while loop
            }
        }
        while ((line = br.readLine()) != null) {
            System.out.println(line);
        }

        br.close();

任何人都可以把我推向正确的方向吗？

干杯！

Answer 1

下面的代码对我有用！

要到达 JSON 的所需部分，我首先必须遍历树层次结构。这意味着打开 "features"、"geometry" 最后 "coordinates" 以获取坐标。在最后添加线串和括号以再次转换为适当的 JSON 文件。

    // look for features
    if (jsoninput.contains("features")) {
        jsonArray1 = obj.getJSONArray("features");
        System.out.println(jsonArray1+ "\n");
    }

    // look for geometry
    if (jsoninput.contains("geometry")) {
        jsonArray2 = obj.getJSONObject("geometry");
        System.out.println(jsonArray2+ "\n");
        jsonArray3 = jsonArray2.getJSONArray("coordinates");
        output = ""+jsonArray3;
        System.out.println(output);
    }


    // no features of geometry, just check "coordinates"
    if (!jsoninput.contains("features") & !jsoninput.contains("geometry")) {
        jsonArray4 = obj.getJSONArray("coordinates");
        output = ""+jsonArray4;
        System.out.println(output);
    }

    // output is just a String of coordinates, add LineString prefix and  
    // brackets to make it a proper JSON again                     
    String finaloutput = "{\"type\": \"LineString\",\"coordinates\":"
            + output + "}";

    System.out.println(finaloutput);

从特定单词开始从 geojson 读取

Reading from geojson starting from specific word

string

bufferedreader

geojson