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复杂json解析

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目标：借助fastjson将json串解析成Java对象。json串及java对象结构如下：

json串

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{
    "positionData": {
        "deadReckoningPosition": {
            "lon": "111.91113900000000",
            "lat": "21.68800700000000"
        },
        "rawPosition": {
            "lon": "115.91113800000000",
            "lat": "28.68801700000000"
        },        
        "deltaPositionArray": [
            {
                "deltaTimeInSec": "0",
                "deltaLon": "0.00000000000000",
                "deltaLat": "0.00000000000000"
            },
            {
                "deltaTimeInSec": "1000",
                "deltaLon": "100.00000000000000",
                "deltaLat": "20.00000000000000"
            }
        ],
        "heading": "10",
        "visibleSatelliteNumber": "5",
        "altitude": "2",
        "rawPositionUncertaintyEstimate": "3"
    }
}

java对象

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public class PositionData {
    private Position deadReckoningPosition;
    private Position rawPosition;
    private List<DeltaPosition> deltaPositionArray;
    private String heading;
    private Short visibleSatelliteNumber;
    private Short altitude;
    private Short rawPositionUncertaintyEstimate;

    //以下省略getter/setter
    ...
}

首先，在pom文件中引入fastjson依赖

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<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.16</version>
</dependency>

然后，编写测试类

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public static void main(String[] args) {
    String str = "{\"positionData\":{\"deadReckoningPosition\":{\"lon\":\"111.91113900000000\",\"lat\":\"21.68800700000000\"},\"rawPosition\":{\"lon\":\"115.91113800000000\",\"lat\":\"28.68801700000000\"},\"deltaPositionArray\":[{\"deltaTimeInSec\":\"0\",\"deltaLon\":\"0.00000000000000\",\"deltaLat\":\"0.00000000000000\"},{\"deltaTimeInSec\":\"1000\",\"deltaLon\":\"100.00000000000000\",\"deltaLat\":\"20.00000000000000\"}],\"heading\":\"10\",\"visibleSatelliteNumber\":\"5\",\"altitude\":\"2\",\"rawPositionUncertaintyEstimate\":\"3\"}}";

    JSONObject object = JSON.parseObject(str);
    JSONObject positionDataJson = (JSONObject) object.get("positionData");

    positionDataJson.getObject("deadReckoningPosition", Position.class);
    positionDataJson.getObject("rawPosition", Position.class);

    JSONArray deltaPositionArray = positionDataJson.getJSONArray("deltaPositionArray");
    JSON.parseArray(deltaPositionArray.toJSONString(), DeltaPosition.class);

    PositionData positionData = JSON.parseObject(positionDataJson.toJSONString(), PositionData.class);
    System.out.println(positionData);
}

测试结果如下：

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PositionData [deadReckoningPosition=Position [lon=111.91113900000000, lat=21.68800700000000], heading=10, deltaPositionArray=[DeltaPosition [deltaTimeInSec=0, deltaLon=0.00000000000000, deltaLat=0.00000000000000], DeltaPosition [deltaTimeInSec=1000, deltaLon=100.00000000000000, deltaLat=20.00000000000000]], visibleSatelliteNumber=5, altitude=2, rawPosition=Position [lon=115.91113800000000, lat=28.68801700000000], rawPositionUncertaintyEstimate=3]

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