我正在嘗試為嵌套的 JsonObject 編寫一個通用代碼來映射轉(zhuǎn)換。我有一個示例 JSONObject 作為{ "glossary": { "title": "example glossary", "GlossDiv": { "title": "S", "GlossList": { "GlossEntry": { "ID": "SGML", "SortAs": "SGML", "GlossTerm": "Standard Generalized \n Markup Language", "GlossDef": { "para": "A DocBook.", "GlossSeeAlso": [ "GML", "XML" ] }, "GlossSee": "markup" } } } }}我想將其轉(zhuǎn)換為具有鍵值的地圖glossary.title = "example glossary",glossary.GlossDiv.title = "S",glossary.GlossDiv.GlossList.GlossEntry.ID ="SGML",glossary.GlossDiv.GlossList.GlossEntry.SortAs ="SGML",glossary.GlossDiv.GlossList.GlossEntry.GlossTerm="Standard Generalized Markup Language",glosary.GlossDiv.GlossList.GlossEntry.GlossDef.para ="A DocBook.",glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso_0 = "GML",glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso_1 = "XML",glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSee = "markup"
3 回答
哆啦的時光機(jī)
TA貢獻(xiàn)1779條經(jīng)驗 獲得超6個贊
這是使用以下方法Map從 json 字符串中讀取的方法Jackson：
public final class JsonUtils {
public static <T> Map<String, T> readMap(String json) throws Exception {
if (json == null)
return null;
ObjectReader reader = new ObjectMapper().readerFor(Map.class);
MappingIterator<Map<String, T>> it = reader.readValues(json);
if (it.hasNextValue()) {
Map<String, T> res = it.next();
return res.isEmpty() ? Collections.emptyMap() : res;
}
return Collections.emptyMap();
}
}
這是Map使用給定的實用程序方法從 json讀取的方法：
Map<String, String> map = flatMap(new LinkedHashMap<>(), "", JsonUtils.readMap(json));
最后，這是如何轉(zhuǎn)換Map為 required Map（可能這可以在 Jackson 引擎中完成，提供自定義反序列化器左右，但我不知道具體如何，這就是為什么我更容易手動實現(xiàn)它）：
public static Map<String, String> flatMap(Map<String, String> res, String prefix, Map<String, Object> map) {
for (Map.Entry<String, Object> entry : map.entrySet()) {
String key = prefix + entry.getKey();
Object value = entry.getValue();
if (value instanceof Map)
flatMap(res, key + '.', (Map<String, Object>)value);
else
res.put(key, String.valueOf(value));
}
return res;
}
侃侃無極
TA貢獻(xiàn)2051條經(jīng)驗 獲得超10個贊
Jackson JSON 是一個非?？岬膸?，它為您完成了這項工作。我在下面寫了一個簡單的例子，但你應(yīng)該能夠?qū)⑺鼞?yīng)用到你的 JSONObject。
假設(shè)您有一個A.class屬性B.class，而該屬性又具有嵌套屬性C.class
@JsonPropertyOrder({ "b" })
class A {
@JsonProperty("b")
public B b;
@JsonProperty("b")
public B getB() {
return b;
}
@JsonProperty("b")
public void setB(B b) {
this.b = b;
}
}
@JsonPropertyOrder({ "c" })
class B {
@JsonProperty("c")
public C c;
@JsonProperty("c")
public C getC() {
return c;
}
@JsonProperty("c")
public void setC(C c) {
this.c = c;
}
}
@JsonPropertyOrder({ "d" })
class C {
@JsonProperty("d")
public String d;
@JsonProperty("d")
public String getD() {
return d;
}
@JsonProperty("d")
public void setD(String d) {
this.d = d;
}
}
您可以將嵌套的 JSONObject{"b":{"c":{"d":"test"}}}轉(zhuǎn)換成A.class這樣：
C c = new C();
c.setD("test");
B b = new B();
b.setC(c);
JSONObject obj = new JSONObject();
obj.put("b", b);
String jsonAsString = new Gson().toJson(obj);
A a = mapper.readValue(jsonAsString, A.class);
同樣，您應(yīng)該能夠?qū)?JSONObject 轉(zhuǎn)換為您想要的任何類型。希望這可以幫助
POPMUISE
TA貢獻(xiàn)1765條經(jīng)驗 獲得超5個贊
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class JsonToMapConvertor {
private static HashMap<String, Object> mapReturn = new HashMap<String, Object>();
public static JsonParser parser = new JsonParser();
public static void main(String[] args) throws Exception{
String json ="add your Json";
HashMap<String, Object> map = createHashMapFromJsonString(json,"");
for (Map.Entry<String, Object> entry : map.entrySet()) {
if(!entry.getValue().toString().contains("{"))
System.out.println(entry.getKey()+" : "+entry.getValue());
}
}
public static HashMap<String, Object> createHashMapFromJsonString(String json,String prefix) {
JsonObject object = (JsonObject) parser.parse(json);
Set<Map.Entry<String, JsonElement>> set = object.entrySet();
Iterator<Map.Entry<String, JsonElement>> iterator = set.iterator();
while (iterator.hasNext()) {
Map.Entry<String, JsonElement> entry = iterator.next();
String key = entry.getKey();
if(prefix.length()!=0){
key = prefix + "."+key;
}
JsonElement value = entry.getValue();
if (null != value) {
if (!value.isJsonPrimitive()) {
if (value.isJsonObject()) {
mapReturn.put(key,value);
mapReturn.put(key, createHashMapFromJsonString(value.toString(),key));
} else if (value.isJsonArray() && value.toString().contains(":")) {
List<HashMap<String, Object>> list = new ArrayList<>();
JsonArray array = value.getAsJsonArray();
if (null != array) {
for (JsonElement element : array) {
list.add(createHashMapFromJsonString(value.toString(),key));
}
mapReturn.put(key, list);
}
} else if (value.isJsonArray() && !value.toString().contains(":")) {
mapReturn.put(key, value.getAsJsonArray());
}
} else {
mapReturn.put(key, value.getAsString());
}
}
}
return mapReturn;
}
}
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