wandermonk:
要件は、JSONオブジェクトを平坦化への入力JSONオブジェクトのための一般的な平坦化ユーティリティを作成することです。
以下のようなサンプルJSONのルックス
{
"Source": "source-1",
"Rows": [
{
"Keys": {
"device-id": "BC04-EBH-N3K-01",
"interface-name": "TenGigE0/0/0/39",
"node-name": "0/0/CPU0"
},
"Timestamp": 1567621527656,
"inner": {
"donm": {
"id": "0062",
"mol": {
"rem": 30,
"len": 11,
"org": {
"ldp": [
{
"t": 486,
"o": 322
},
{
"t": 487,
"o": 32,
"twss": 1,
"tlv": "00:01"
}
]
},
"chlen": 14,
"poe": 5,
"combs": 10,
"chaype": 4,
"rek": 0,
"rem-um": 67
},
"detail": {
"enas": "B,R",
"systes": "B,R",
"timng": 91,
"syn": "C",
"met-type": 0,
"neses": {
"lldEDIT": [
{
"ium": 830,
"m": 1,
"ass": {
"ape": "ipv4",
"ipvs": "94"
}
}
]
},
"pess": "0008",
"por]d": 0,
"pon": "BCtive",
"sysme": "BC1"
},
"reme": "Bu1",
"hean": 0,
"porl": "Et1"
}
}
}
],
"Tey": {
"epath": "Cgetail",
"sustr": "MX",
"coime": 1567621527653,
"msp": 1567621527653,
"come": 1567621527660,
"nor": "BC5",
"cid": 14789654
}
}
私は3つのレベルにそれを平らにしようとしていると、以下のユーティリティを思い付いてきました。しかし、私は配列とString型の値に対処する必要がありますとき、物事が複雑化している、長い、タイムスタンプなどはまた、私は、ネストされたキーが一意性を維持することが可能かを理解することができません。
public static Map<String,Object> flattenJson(JsonNode input){
Map<String,Object> finalMap = new HashMap<>();
ObjectMapper datamapper = new ObjectMapper();
Map<String,Object> topLevelJsonMap = datamapper.convertValue(input,Map.class);
Set<String> topLevelKeys = topLevelJsonMap.keySet();
for(String topLevelKey : topLevelKeys){
System.out.println("Key :::: "+topLevelKey);
Object topLevelData = topLevelJsonMap.get(topLevelKey);
System.out.println("value :::: "+topLevelData.toString());
if(topLevelData instanceof ArrayNode){
ArrayNode arrayOfData = (ArrayNode) topLevelData;
for(JsonNode dataNode : arrayOfData){
flattenJson(input);
}
} else if(topLevelData instanceof JsonNode){
Map<String,Object> innerLevelJsonMap = datamapper.convertValue(topLevelData,Map.class);
Set<String> innerLevelKeys = innerLevelJsonMap.keySet();
for(String innerLevelKey : innerLevelKeys){
System.out.println("inner key :::: "+innerLevelKey);
flattenJson((JsonNode) innerLevelJsonMap.get(innerLevelKey));
}
}else {
finalMap.put(topLevelKey,topLevelData);
}
}
return finalMap;
}
すべてのヘルプは大歓迎です。
マイケルZiober:
キー名との競合を避けるために、あなたは使用することができますJSONポインタ、それらを作成するための仕様を。またによってサポートされていJackson
ますが、横断する、後でそれらを使用することができるように、ライブラリJsonNode
のノードを。
単純な実装は、以下のようになります。
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import java.io.File;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicInteger;
public class JsonApp {
public static void main(String[] args) throws Exception {
File jsonFile = new File("./test.json");
ObjectMapper mapper = new ObjectMapper();
JsonNode root = mapper.readTree(jsonFile);
Map<String, JsonNode> map = new JsonFlattener(root).flatten();
System.out.println("Use key-value pairs:");
map.forEach(
(k, v) -> {
System.out.println(k + " => " + v);
});
System.out.println();
System.out.println("Use pointers:");
map.forEach(
(k, v) -> {
System.out.println(k + " => " + root.at(k));
});
}
}
class JsonFlattener {
private final Map<String, JsonNode> json = new LinkedHashMap<>(64);
private final JsonNode root;
JsonFlattener(JsonNode node) {
this.root = Objects.requireNonNull(node);
}
public Map<String, JsonNode> flatten() {
process(root, "");
return json;
}
private void process(JsonNode node, String prefix) {
if (node.isObject()) {
ObjectNode object = (ObjectNode) node;
object
.fields()
.forEachRemaining(
entry -> {
process(entry.getValue(), prefix + "/" + entry.getKey());
});
} else if (node.isArray()) {
ArrayNode array = (ArrayNode) node;
AtomicInteger counter = new AtomicInteger();
array
.elements()
.forEachRemaining(
item -> {
process(item, prefix + "/" + counter.getAndIncrement());
});
} else {
json.put(prefix, node);
}
}
}
上記のコードを印刷:
Use key-value pairs:
/Source => "source-1"
/Rows/0/Keys/device-id => "BC04-EBH-N3K-01"
/Rows/0/Keys/interface-name => "TenGigE0/0/0/39"
/Rows/0/Keys/node-name => "0/0/CPU0"
/Rows/0/Timestamp => 1567621527656
/Rows/0/inner/donm/id => "0062"
/Rows/0/inner/donm/mol/rem => 30
/Rows/0/inner/donm/mol/len => 11
/Rows/0/inner/donm/mol/org/ldp/0/t => 486
/Rows/0/inner/donm/mol/org/ldp/0/o => 322
/Rows/0/inner/donm/mol/org/ldp/1/t => 487
/Rows/0/inner/donm/mol/org/ldp/1/o => 32
/Rows/0/inner/donm/mol/org/ldp/1/twss => 1
/Rows/0/inner/donm/mol/org/ldp/1/tlv => "00:01"
/Rows/0/inner/donm/mol/chlen => 14
/Rows/0/inner/donm/mol/poe => 5
/Rows/0/inner/donm/mol/combs => 10
/Rows/0/inner/donm/mol/chaype => 4
/Rows/0/inner/donm/mol/rek => 0
/Rows/0/inner/donm/mol/rem-um => 67
/Rows/0/inner/donm/detail/enas => "B,R"
/Rows/0/inner/donm/detail/systes => "B,R"
/Rows/0/inner/donm/detail/timng => 91
/Rows/0/inner/donm/detail/syn => "C"
/Rows/0/inner/donm/detail/met-type => 0
/Rows/0/inner/donm/detail/neses/lldEDIT/0/ium => 830
/Rows/0/inner/donm/detail/neses/lldEDIT/0/m => 1
/Rows/0/inner/donm/detail/neses/lldEDIT/0/ass/ape => "ipv4"
/Rows/0/inner/donm/detail/neses/lldEDIT/0/ass/ipvs => "94"
/Rows/0/inner/donm/detail/pess => "0008"
/Rows/0/inner/donm/detail/por]d => 0
/Rows/0/inner/donm/detail/pon => "BCtive"
/Rows/0/inner/donm/detail/sysme => "BC1"
/Rows/0/inner/donm/reme => "Bu1"
/Rows/0/inner/donm/hean => 0
/Rows/0/inner/donm/porl => "Et1"
/Tey/epath => "Cgetail"
/Tey/sustr => "MX"
/Tey/coime => 1567621527653
/Tey/msp => 1567621527653
/Tey/come => 1567621527660
/Tey/nor => "BC5"
/Tey/cid => 14789654
Use pointers:
/Source => "source-1"
/Rows/0/Keys/device-id => "BC04-EBH-N3K-01"
/Rows/0/Keys/interface-name => "TenGigE0/0/0/39"
/Rows/0/Keys/node-name => "0/0/CPU0"
/Rows/0/Timestamp => 1567621527656
/Rows/0/inner/donm/id => "0062"
/Rows/0/inner/donm/mol/rem => 30
/Rows/0/inner/donm/mol/len => 11
/Rows/0/inner/donm/mol/org/ldp/0/t => 486
/Rows/0/inner/donm/mol/org/ldp/0/o => 322
/Rows/0/inner/donm/mol/org/ldp/1/t => 487
/Rows/0/inner/donm/mol/org/ldp/1/o => 32
/Rows/0/inner/donm/mol/org/ldp/1/twss => 1
/Rows/0/inner/donm/mol/org/ldp/1/tlv => "00:01"
/Rows/0/inner/donm/mol/chlen => 14
/Rows/0/inner/donm/mol/poe => 5
/Rows/0/inner/donm/mol/combs => 10
/Rows/0/inner/donm/mol/chaype => 4
/Rows/0/inner/donm/mol/rek => 0
/Rows/0/inner/donm/mol/rem-um => 67
/Rows/0/inner/donm/detail/enas => "B,R"
/Rows/0/inner/donm/detail/systes => "B,R"
/Rows/0/inner/donm/detail/timng => 91
/Rows/0/inner/donm/detail/syn => "C"
/Rows/0/inner/donm/detail/met-type => 0
/Rows/0/inner/donm/detail/neses/lldEDIT/0/ium => 830
/Rows/0/inner/donm/detail/neses/lldEDIT/0/m => 1
/Rows/0/inner/donm/detail/neses/lldEDIT/0/ass/ape => "ipv4"
/Rows/0/inner/donm/detail/neses/lldEDIT/0/ass/ipvs => "94"
/Rows/0/inner/donm/detail/pess => "0008"
/Rows/0/inner/donm/detail/por]d => 0
/Rows/0/inner/donm/detail/pon => "BCtive"
/Rows/0/inner/donm/detail/sysme => "BC1"
/Rows/0/inner/donm/reme => "Bu1"
/Rows/0/inner/donm/hean => 0
/Rows/0/inner/donm/porl => "Et1"
/Tey/epath => "Cgetail"
/Tey/sustr => "MX"
/Tey/coime => 1567621527653
/Tey/msp => 1567621527653
/Tey/come => 1567621527660
/Tey/nor => "BC5"
/Tey/cid => 14789654