Java GSON 不会反序列化所有字段，即使它们属于同一类型

Question

我有课：

public class SentPlayer {
    final String uuid;
    final String playerName;
    final String universeUuid;
/* some get methods and constructors */
}

public class PlayerMsg {
    public final SentPlayer player;
    public final String msg;
/* constructors and such */
}

然后我有这个来自 api 的 JSON：

{
    "player": {
        "uuid": "",
        "playerName": "Rushmore75",
        "universeUuid": "9dae671e-91ed-440e722c12"
    },
    "msg": "1234"
}

但是，当我将所说的 json 反序列化到

PlayerMsg

类时，除

"playerName"

之外的所有字段都反序列化，而

playerName

只是

null

而不是

"Rushmore75"

。我正在使用启用了“serializeNulls”的默认 GSON 配置。使用 gson 2.10

Answer 1

试试这个：

public class SentPlayer {
    @SerializedName("uuid")
    final String uuid;
    @SerializedName("playerName")
    final String playerName;
    @SerializedName("universeUuid")
    final String universeUuid;
    // constructors and getters
}

Answer 2

从两个类的所有字段中删除

final

关键字。它会序列化。

工作示例：

public class SentPlayer {

    String uuid;
    String playerName;
    String universeUuid;

    public String getUuid() {
        return uuid;
    }

    public String getPlayerName() {
        return playerName;
    }

    public String getUniverseUuid() {
        return universeUuid;
    }

    @Override
    public String toString() {
        return "SentPlayer [uuid=" + uuid + ", playerName=" + playerName + ", universeUuid=" + universeUuid + "]";
    }

}

---

public class PlayerMsg {
    
    public SentPlayer player;
    
    public String msg;

    public SentPlayer getPlayer() {
        return player;
    }

    public String getMsg() {
        return msg;
    }

    @Override
    public String toString() {
        return "PlayerMsg [player=" + player + ", msg=" + msg + "]";
    }
}

---

@RestController
public class ControllerTest {

    @GetMapping("test")
    public void test(@RequestBody String msg) {
        Gson gson = new GsonBuilder().serializeNulls().create();
        PlayerMsg example = gson.fromJson(msg, PlayerMsg.class);
        System.out.println(example);
    }

}

输出：

PlayerMsg [player=SentPlayer [uuid=, playerName=Anish, universeUuid=123df], msg=1234]