用PHP查询JSON（GeoJSON…）以提取值

我有这个GeoJSON

{
    "more": true,
    "features": [{
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.672117, 44.901697],
                [7.672137, 44.901766],
                [7.672167, 44.901828],
                [7.672207, 44.901888]
            ],
            "bbox": [7.671508, 44.901697, 7.676434, 44.912198]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.901697,
                "min_lon": 7.671508,
                "max_lat": 44.912198,
                "max_lon": 7.676434
            },
            "captured_at": 1432989312291,
            "key": "Lm7zCv3niXy9jBDmaKEuzw",
            "keys": ["O-UdnDpmS8_WTQgOqkj8_w", "BQUybUzc2liYTx5Rc6lEEA", "-n5Yw2WEgnLTVk4kVJbnGQ"]
        }
    }, {
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.67173, 44.912223],
                [7.671718, 44.912186],
                [7.671685, 44.912138],
                [7.671668, 44.912084]
            ],
            "bbox": [7.671508, 44.911598, 7.67173, 44.912223]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.911598,
                "min_lon": 7.671508,
                "max_lat": 44.912223,
                "max_lon": 7.67173
            },
            "captured_at": 1432985665206,
            "key": "gP_RMGgi8Vs26HEtuQBzBw",
            "keys": ["0PZ_0b5gDwgv_wGR-PaH6g", "D6B1-IcUpWc6rEq2v-a4AQ", "L9uEPoXiSjagWY2hPTRpBg"]
        }
    }, {
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.671187, 44.911639],
                [7.671243, 44.911675],
                [7.671249, 44.911742],
                [7.671262, 44.911796]
            ],
            "bbox": [7.671137, 44.911639, 7.671674, 44.912609]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.911639,
                "min_lon": 7.671137,
                "max_lat": 44.912609,
                "max_lon": 7.671674
            },
            "captured_at": 1433505642167,
            "key": "wGJ8pn9A41vdyQN-WSIT_Q",
            "keys": ["DVZQEFI_8qczLI99NCpDkQ", "edPjE41cA8h4HIzmbS0MyA", "JYghFOvUuPPtpQL5ff0lmQ"]
        }
    }, {
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.671765, 44.912323],
                [7.671756, 44.912292],
                [7.671746, 44.912258],
                [7.671734, 44.912223]
            ],
            "bbox": [7.671481, 44.911138, 7.672658, 44.912323]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.911138,
                "min_lon": 7.671481,
                "max_lat": 44.912323,
                "max_lon": 7.672658
            },
            "captured_at": 1432743361672,
            "key": "4x5ay3CHwgxFTdIIQg81-A",
            "keys": ["lx30DGH6cFpa5VWD98pDDA", "xvJ2X2FeFfCDm2cVvPgS6A", "gBJFHuS19-2k9fs3_vJ8zQ"]
        }
    }],
    "type": "FeatureCollection"
}

。。。我需要搜索值D6B1-IcUpWc6rEq2v-a4AQ，当我找到它时，返回键标记相关的值，所以在本例中是gP_RMGgi8Vs26HEtuQBzBw

有什么用PHP实现的建议/示例吗

提前非常感谢

Cesare

您需要对字符串进行json_解码，然后对每个解码的数组进行解码

我写函数findKey。您需要传递两个变量：json字符串和要搜索的键

function findKey($geoJson, $key) {
    $geoArray = json_decode($geoJson, true);
    foreach ($geoArray['features'] as $geoFeature) {
        if (in_array($key, $geoFeature['properties']['keys'])) {
            return $geoFeature['properties']['key'];
            }
    }
}

此代码示例查找所需的密钥gP_RMGgi8Vs26HEtuQBzBw：

<?php

$geoJson = <<<EOF
{
    "more": true,
    "features": [{
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.672117, 44.901697],
                [7.672137, 44.901766],
                [7.672167, 44.901828],
                [7.672207, 44.901888]
            ],
            "bbox": [7.671508, 44.901697, 7.676434, 44.912198]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.901697,
                "min_lon": 7.671508,
                "max_lat": 44.912198,
                "max_lon": 7.676434
            },
            "captured_at": 1432989312291,
            "key": "Lm7zCv3niXy9jBDmaKEuzw",
            "keys": ["O-UdnDpmS8_WTQgOqkj8_w", "BQUybUzc2liYTx5Rc6lEEA", "-n5Yw2WEgnLTVk4kVJbnGQ"]
        }
    }, {
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.67173, 44.912223],
                [7.671718, 44.912186],
                [7.671685, 44.912138],
                [7.671668, 44.912084]
            ],
            "bbox": [7.671508, 44.911598, 7.67173, 44.912223]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.911598,
                "min_lon": 7.671508,
                "max_lat": 44.912223,
                "max_lon": 7.67173
            },
            "captured_at": 1432985665206,
            "key": "gP_RMGgi8Vs26HEtuQBzBw",
            "keys": ["0PZ_0b5gDwgv_wGR-PaH6g", "D6B1-IcUpWc6rEq2v-a4AQ", "L9uEPoXiSjagWY2hPTRpBg"]
        }
    }, {
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.671187, 44.911639],
                [7.671243, 44.911675],
                [7.671249, 44.911742],
                [7.671262, 44.911796]
            ],
            "bbox": [7.671137, 44.911639, 7.671674, 44.912609]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.911639,
                "min_lon": 7.671137,
                "max_lat": 44.912609,
                "max_lon": 7.671674
            },
            "captured_at": 1433505642167,
            "key": "wGJ8pn9A41vdyQN-WSIT_Q",
            "keys": ["DVZQEFI_8qczLI99NCpDkQ", "edPjE41cA8h4HIzmbS0MyA", "JYghFOvUuPPtpQL5ff0lmQ"]
        }
    }, {
        "type": "Feature",
        "geometry": {
            "type": "LineString",
            "coordinates": [
                [7.671765, 44.912323],
                [7.671756, 44.912292],
                [7.671746, 44.912258],
                [7.671734, 44.912223]
            ],
            "bbox": [7.671481, 44.911138, 7.672658, 44.912323]
        },
        "properties": {
            "boundary": {
                "min_lat": 44.911138,
                "min_lon": 7.671481,
                "max_lat": 44.912323,
                "max_lon": 7.672658
            },
            "captured_at": 1432743361672,
            "key": "4x5ay3CHwgxFTdIIQg81-A",
            "keys": ["lx30DGH6cFpa5VWD98pDDA", "xvJ2X2FeFfCDm2cVvPgS6A", "gBJFHuS19-2k9fs3_vJ8zQ"]
        }
    }],
    "type": "FeatureCollection"
}
EOF;

$key = 'D6B1-IcUpWc6rEq2v-a4AQ';

function findKey($geoJson, $key) {
    $geoArray = json_decode($geoJson, true);
    foreach ($geoArray['features'] as $geoFeature) {
        if (in_array($key, $geoFeature['properties']['keys'])) {
            return $geoFeature['properties']['key'];
            }
    }
}

var_dump(findKey($geoJson,$key));