Java JSON - 无法使用 Jackson 在对象中序列化 JSONObject
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JSON - Unable to serialize JSONObject within Object using Hymanson
提问by dev ray
I have the following class:
我有以下课程：
class A{
String abc;
String def;
// appropriate getters and setters with JsonProperty Annotation
}
and I call Hymansons objectMapper.writeValueAsString(A)which works fine.
我称之为Hymansons objectMapper.writeValueAsString(A)工作正常。
Now I need to add another instance member:
现在我需要添加另一个实例成员：
class A{
String abc;
String def;
JSONObject newMember; // No, I cannot Stringify it, it needs to be JSONObject
// appropriate getters and setters with JsonProperty Annotation
}
but when I serialize, I am getting exception:
但是当我序列化时，我得到了异常：
org.codehaus.Hymanson.map.JsonMappingException: No serializer found for class org.json.JSONObject and no properties discovered to create BeanSerializer
I tried JSONNode but it gave Output as {outerjson:"{innerjson}"} not {outerjson:{innerjson}}.
我尝试了 JSONNode，但它给出了输出为 {outerjson: "{innerjson} "} 而不是 {outerjson:{innerjson}}。
Is it possible to use Hymanson to achieve the above output, i.e. JSONObject within JSONObject?
是否可以使用 Hymanson 来实现上述输出，即 JSONObject 中的 JSONObject？
回答by Alexey Gavrilov
Well, if you cannot replace the JSONObject on a POJO or a Map, then you can write a custom serializer. Here is an example:
好吧，如果您无法替换 POJO 或 Map 上的 JSONObject，那么您可以编写自定义序列化程序。下面是一个例子：
public class HymansonJSONObject {
public static class MyObject {
public final String string;
public final JSONObject object;
@JsonCreator
public MyObject(@JsonProperty("string") String string, @JsonProperty("object") JSONObject object) {
this.string = string;
this.object = object;
}
@Override
public String toString() {
return "MyObject{" +
"string='" + string + '\'' +
", object=" + object +
'}';
}
}
public static void main(String[] args) throws IOException {
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule("org.json");
module.addSerializer(JSONObject.class, new JsonSerializer<JSONObject>() {
@Override
public void serialize(JSONObject value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
jgen.writeRawValue(value.toString());
}
});
module.addDeserializer(JSONObject.class, new JsonDeserializer<JSONObject>() {
@Override
public JSONObject deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException {
Map<String, Object> bean = jp.readValueAs(new TypeReference<Map<String, Object>>() {});
return new JSONObject(bean);
}
});
mapper.registerModule(module);
JSONObject object = new JSONObject(Collections.singletonMap("key", "value"));
String json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(new MyObject("string", object));
System.out.println("JSON: " + json);
System.out.println("Object: " + mapper.readValue(json, MyObject.class));
}
}
Output:
输出：
JSON: {
"string" : "string",
"object" : {"key":"value"}
}
Object: MyObject{string='string', object={"key":"value"}}
回答by Brijesh Patel
Use JsonNode instead of JSONObject.
使用 JsonNode 而不是 JSONObject。
JsonNode jsonNode = JsonLoader.fromString(YOUR_STRING);
回答by banterCZ
What about to use Hymanson-datatype-json-org
要用什么 Hymanson-datatype-json-org
// import com.fasterxml.Hymanson.datatype.jsonorg.JsonOrgModule;
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JsonOrgModule());
回答by wvdz
Use @JsonSerializewith the attribute and implement a custom serializer.
@JsonSerialize与属性一起使用并实现自定义序列化程序。
@JsonSerialize(using = JsonObjectSerializer.class)
private JSONObject jsonObject;
public static class JsonObjectSerializer extends JsonSerializer<JSONObject> {
@Override
public void serialize(JSONObject jsonObject, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
jsonGenerator.writeRawValue(jsonObject.toString());
}
}
