我有以下格式的JSON结果，JSON Lint将其显示为“有效响应”。
我的问题是：如何访问“question_mark”的内容，因为“141”，“8911”等都是动态值？
我的示例代码用于访问“product”的值。
//Consider I have the first <code>JSONObject</code> of the "search_result" array and
//I access it's "product" value as below.
String product = jsonObject.optString("product"); //where jsonObject is of type JSONObject.
//<code>product<code> now contains "abc".
JSON：
{
"status": "OK",
"search_result": [
{
"product": "abc",
"id": "1132",
"question_mark": {
"141": {
"count": "141",
"more_description": "this is abc",
"seq": "2"
},
"8911": {
"count": "8911",
"more_desc": "this is cup",
"seq": "1"
}
},
"name": "some name",
"description": "This is some product"
},
{
"product": "XYZ",
"id": "1129",
"question_mark": {
"379": {
"count": "379",
"more_desc": "this is xyz",
"seq": "5"
},
"845": {
"count": "845",
"more_desc": "this is table",
"seq": "6"
},
"12383": {
"count": "12383",
"more_desc": "Jumbo",
"seq": "4"
},
"257258": {
"count": "257258",
"more_desc": "large",
"seq": "1"
}
},
"name": "some other name",
"description": "this is some other product"
}
]
}
我的问题标题“动态密钥”可能是错误的，但我不知道在这一点上什么是这个问题的更好的名称。
任何帮助将不胜感激！
使用JSONObject keys()获取密钥，然后迭代每个密钥以获得动态值。
代码大致如下：
// searchResult refers to the current element in the array "search_result"
JSONObject questionMark = searchResult.getJSONObject("question_mark");
Iterator keys = questionMark.keys();
while(keys.hasNext()) {
// loop to get the dynamic key
String currentDynamicKey = (String)keys.next();
// get the value of the dynamic key
JSONObject currentDynamicValue = questionMark.getJSONObject(currentDynamicKey);
// do something here with the value...
}
另一种可能性是使用Gson（注意，我在这里使用lombok来生成getter / setter，toString等）：
package so7304002;
import java.util.List;
import java.util.Map;
import lombok.AccessLevel;
import lombok.Data;
import lombok.NoArgsConstructor;
import com.google.gson.Gson;
import com.google.gson.annotations.SerializedName;
import com.google.gson.reflect.TypeToken;
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public final class JsonDemo {
@Data
private static class MyMap {
private int count;
@SerializedName("more_description")
private String moreDescription;
private int seq;
}
@Data
private static class Product {
private String product;
private int id;
@SerializedName("question_mark")
private Map<String, MyMap> questionMark;
}
@Data
private static class MyObject {
private String status;
@SerializedName("search_result")
private List<Product> searchResult;
}
private static final String INPUT = ""; // your JSON
public static void main(final String[] arg) {
final MyObject fromJson = new Gson().fromJson(INPUT,
new TypeToken<MyObject>(){}.getType());
final List<Product> searchResult = fromJson.getSearchResult();
for (final Product p : searchResult) {
System.out.println("product: " + p.getProduct()
+ "\n" + p.getQuestionMark()+ "\n");
}
}
}
输出：
product: abc
{141=JsonDemo.MyMap(count=141, moreDescription=this is abc, seq=2),
8911=JsonDemo.MyMap(count=8911, moreDescription=null, seq=1)}
product: XYZ
{379=JsonDemo.MyMap(count=379, moreDescription=null, seq=5),
845=JsonDemo.MyMap(count=845, moreDescription=null, seq=6),
12383=JsonDemo.MyMap(count=12383, moreDescription=null, seq=4),
257258=JsonDemo.MyMap(count=257258, moreDescription=null, seq=1)}
使用GSON也可以做同样的事情，但不是使用GSON转换器适配器转换为POJO。我们将手动解析它。这使我们在动态JSON数据的情况下具有灵活性。 让我们说JSON格式就像我的情况一样。
{
"dateWiseContent": {
"02-04-2017": [
{
"locality": " Cross Madian Cross Rd No 4"
}
],
"04-04-2017": [
{
"locality": "Dsilva Wadi"
},
{
"locality": " Cross Madian Cross Rd No 4",
"appointments": []
}
]
}
}
在这种情况下，dateWiseContent具有动态对象键，因此我们将使用JsonParser类解析此json字符串。
//parsing string response to json object
JsonObject jsonObject = (JsonObject) new JsonParser().parse(resource);
//getting root object
JsonObject dateWiseContent = jsonObject.get("dateWiseContent").getAsJsonObject();
使用Map.Entry<String, JsonElement>获取动态密钥，如下所示
// your code goes here
for (Map.Entry<String, JsonElement> entry : dateWiseContent.entrySet()) {
//this gets the dynamic keys
String dateKey = entry.getKey();
//you can get any thing now json element,array,object according to json.
JsonArray jsonArrayDates = entry.getValue().getAsJsonArray();
int appointmentsSize = jsonArrayDates.size();
for (int count = 0; count < appointmentsSize; count++) {
JsonObject objectData = jsonArrayDates.get(count).getAsJsonObject();
String locality = objectData.get("locality").getAsString();
}
}
类似地，任何级别的动态json都可以使用Map.Entry<String,JsonElement>进行解析
使用Google Gson的一个例子
来自问题的JSON数据：
{
"status": "OK",
"search_result": [
{
"product": "abc",
"id": "1132",
"question_mark": {
"141": {
"count": "141",
"more_description": "this is abc",
"seq": "2"
},
"8911": {
"count": "8911",
"more_desc": "this is cup",
"seq": "1"
}
},
"name": "some name",
"description": "This is some product"
},
{
"product": "XYZ",
"id": "1129",
"question_mark": {
"379": {
"count": "379",
"more_desc": "this is xyz",
"seq": "5"
},
"845": {
"count": "845",
"more_desc": "this is table",
"seq": "6"
},
"12383": {
"count": "12383",
"more_desc": "Jumbo",
"seq": "4"
},
"257258": {
"count": "257258",
"more_desc": "large",
"seq": "1"
}
},
"name": "some other name",
"description": "this is some other product"
}
]
}
示例代码：
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
public class GsonExercise {
public static void main(String[] args) {
String jsonString = "{\"status\":\"OK\",\"search_result\":[{\"product\":\"abc\",\"id\":\"1132\",\"question_mark\":{\"141\":{\"count\":\"141\",\"more_description\":\"this is abc\",\"seq\":\"2\"},\"8911\":{\"count\":\"8911\",\"more_desc\":\"this is cup\",\"seq\":\"1\"}},\"name\":\"some name\",\"description\":\"This is some product\"},{\"product\":\"XYZ\",\"id\":\"1129\",\"question_mark\":{\"379\":{\"count\":\"379\",\"more_desc\":\"this is xyz\",\"seq\":\"5\"},\"845\":{\"count\":\"845\",\"more_desc\":\"this is table\",\"seq\":\"6\"},\"12383\":{\"count\":\"12383\",\"more_desc\":\"Jumbo\",\"seq\":\"4\"},\"257258\":{\"count\":\"257258\",\"more_desc\":\"large\",\"seq\":\"1\"}},\"name\":\"some other name\",\"description\":\"this is some other product\"}]}";
JsonObject jobj = new Gson().fromJson(jsonString, JsonObject.class);
JsonArray ja = jobj.get("search_result").getAsJsonArray();
ja.forEach(el -> {
System.out.println("product: " + el.getAsJsonObject().get("product").getAsString());
JsonObject jo = el.getAsJsonObject().get("question_mark").getAsJsonObject();
jo.entrySet().stream().forEach(qm -> {
String key = qm.getKey();
JsonElement je = qm.getValue();
System.out.println("key: " + key);
JsonObject o = je.getAsJsonObject();
o.entrySet().stream().forEach(prop -> {
System.out.println("\tname: " + prop.getKey() + " (value: " + prop.getValue().getAsString() + ")");
});
});
System.out.println("");
});
}
}
输出：
product: abc
key: 141
name: count (value: 141)
name: more_description (value: this is abc)
name: seq (value: 2)
key: 8911
name: count (value: 8911)
name: more_desc (value: this is cup)
name: seq (value: 1)
product: XYZ
key: 379
name: count (value: 379)
name: more_desc (value: this is xyz)
name: seq (value: 5)
key: 845
name: count (value: 845)
name: more_desc (value: this is table)
name: seq (value: 6)
key: 12383
name: count (value: 12383)
name: more_desc (value: Jumbo)
name: seq (value: 4)
key: 257258
name: count (value: 257258)
name: more_desc (value: large)
name: seq (value: 1)