我需要序列化/反序列化一个特定的枚举：

public enum Status {
    ONLINE("online"),
    OFFLINE("offline"),
    UNKNOWN("del") {
        @Override
        public String getStatusOld() {
            return "off";
        }
    };

    private final String name;
    Status(String name) {
        this.name = name;
    }

    public String getStatusOld() {
        return name;
    }

    public String toString() {
        return name;
    }

    public static Status typeOf(String name) {
        if (!StringUtils.isEmpty(name)) {
            for (Status type : values()) {
                if (type.name.equalsIgnoreCase(name)) {
                    return type;
                }
                if (type.getStatusOld().equalsIgnoreCase(name)) {
                    return type;
                }
            }
        }
        throw new IllegalArgumentException("Unknown status type: " + name);
    }
}

我的POJO如下所示：

public class User {
    public String name;
    public Status status;
    ...
}

和序列化/反序列化我的enumx 1 m0n1x我已经创建了自定义的序列化程序/反序列化程序：

public class GsonStatusEnumSerializer implements JsonSerializer<Status> {
    @Override
    public JsonElement serialize(Status status, Type type, JsonSerializationContext jsonSerializationContext) {
        return new JsonPrimitive(status.toString());
    }
}
public class GsonStatusEnumDeserializer implements JsonDeserializer<Status> {
    @Override
    public Status deserialize(JsonElement jsonElement, Type type, JsonDeserializationContext jsonDeserializationContext) throws JsonParseException {
        if (jsonElement != null && jsonElement.isJsonPrimitive()) {
            final String status = jsonElement.getAsString();
            if (StringUtils.isNotBlank(status)) {
                return Status.typeOf(status);
            }
        }
        return null;
    }
}

当我尝试序列化我的User类时，Status的值为UNKNOWN，我的自定义序列化程序没有被Gson用于序列化User的状态。我发现这是因为UNKNOWN的值具有不同的类型。

public static void main(String[] args) {
    for (Status value : Status.values()) {
            System.out.println("class = " + value.getClass() + ", value = " + value);
        }
}

我得到的结果如下：

class = class com.test.Status, value = online
class = class com.test.Status$2, value = del
class = class com.test.Status, value = offline

序列化User POJO的主要方法：

public static void main(String[] args) {
    Gson gson = new GsonBuilder()
                .registerTypeAdapter(Status.class, new GsonStatusEnumDeserializer())
                .registerTypeAdapter(Status.class, new GsonStatusEnumSerializer())
                .create();
    User user = new User();
    user.name = "John";
    user.status = Status.UNKNOWN;

    String json = gson.toJson(user);
    User user1 = gson.fromJson(json, User.class);
}

我得到了一个异常：

Exception in thread "main" java.lang.IllegalArgumentException: Unknown process type: UNKNOWN
    at com.test.Status.typeOf(Status.java:97)
    at com.test.GsonStatusEnumDeserializer.deserialize(GsonStatusEnumDeserializer.java:22)
    at com.test.GsonStatusEnumDeserializer.deserialize(GsonStatusEnumDeserializer.java:16)

我如何通过Gson序列化/反序列化它？