com.fasterxml.jackson.databind.JsonMappingException：應用程式被標記為非空但為空

我正在使用 java 11 在 Spring Boot 中撰寫登錄 rest api，這是登錄 api 服務器端代碼：

@PostMapping("/plugin/login")
Response<LoginResponse> pluginLogin(@RequestBody UserLoginRequest request);

這是UserLoginRequest定義：

package biz.user;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.NonNull;
import misc.enumn.DeviceType;
import misc.enumn.app.AppName;
import misc.enumn.user.LoginType;

import java.io.Serializable;

/**
 * @author dolphin
 */
@Data
@NoArgsConstructor
@JsonIgnoreProperties(ignoreUnknown = true)
public class UserLoginRequest implements Serializable {

    /**
     * user.phone
     *
     * @mbggenerated
     */
    @NonNull
    private String phone;

    /**
     * user.password
     *
     * @mbggenerated
     */
    @NonNull
    private String password;

    @NonNull
    private LoginType loginType;

    /**
     * user.phone_region
     *
     * @mbggenerated
     */
    @ApiModelProperty(value = "phone region")
    private String phoneRegion;


    @ApiModelProperty(value = "app")
    @NonNull
    private AppName app;

    @ApiModelProperty(value = "device type")
    private DeviceType deviceType;

    @ApiModelProperty(value = "device type")
    private String deviceId;

    @ApiModelProperty(value = "nick name")
    private String nickname;

    @ApiModelProperty(value = "avatar url")
    private String avatarUrl;
}

當我像這樣呼叫這個api時：

curl 'https://dict.example.top/dict/user/plugin/login' \
  -H 'Connection: keep-alive' \
  -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4753.0 Safari/537.36' \
  -H 'Content-type: application/json' \
  -H 'Accept: */*' \
  -H 'Origin: chrome-extension://alepiijaddmmflnaibdpolcgglgmkpdm' \
  -H 'Sec-Fetch-Site: none' \
  -H 'Sec-Fetch-Mode: cors' \
  -H 'Sec-Fetch-Dest: empty' \
  -H 'Accept-Language: en-US,en;q=0.9' \
  --data-raw '{"phone":"","password":"","deviceId":"xxxx","app":7,"deviceType":7,"loginType":1}' \
  --compressed

服務器顯示錯誤：

Caused by: org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: app is marked non-null but is null; nested exception is com.fasterxml.jackson.databind.JsonMappingException: app is marked non-null but is null
 at [Source: (PushbackInputStream); line: 1, column: 51] (through reference chain: biz.user.UserLoginRequest["app"])

為什么會這樣？我應該怎么做才能解決它？這是AppName 定義：

@Getter
public enum AppName implements BaseEnum {
    CRUISE(1, "cruise"),
    BACK(2, "back"),
    REDDWARF_MUSIC(4, "長歌"),
    REDDWARF_DICT(5, "紅矮星詞典"),
    REDDWARF_ADMIN(6, "紅矮星后臺管理系統"),
    ;

    @JsonValue
    private Integer key;
    private String value;

    AppName(Integer key, String value) {
        this.key = key;
        this.value = value;
    }

    private static final Map<Integer, AppName> mappings;

    static {
        Map<Integer, AppName> temp = new HashMap<>();
        for (AppName courseType : values()) {
            temp.put(courseType.key, courseType);
        }
        mappings = Collections.unmodifiableMap(temp);
    }

    /**
     * @param key
     * @return
     */
    @EnumConvertMethod
    @JsonCreator(mode = JsonCreator.Mode.DELEGATING)
    public static AppName resolve(Integer key) {
        return mappings.get(key);
    }

    public void setKey(Integer key) {
        this.key = key;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public static AppName getAppMarkByValue(String value) {
        AppName datetimeType = null;
        for (AppName type : AppName.values()) {
            if (type.name().equals(value)) {
                datetimeType = type;
            }
        }
        return datetimeType;
    }

    public static AppName getAppMarkByKey(Short key) {
        AppName datetimeType = null;
        for (AppName type : AppName.values()) {
            if (type.key.equals(key)) {
                datetimeType = type;
            }
        }
        return datetimeType;
    }
}

uj5u.com熱心網友回復：

您正在使用列舉來接收應用程式引數，在客戶端上您告訴服務器您的應用程式是 7，但是在您的 AppName 列舉中您沒有定義哪個應用程式是 7。所以當決議 7 時沒有映射任何應用程式時，它會變為空。但是您的龍目島驗證應用程式不能為空，這就是您收到錯誤的原因。解決您的問題，您應該在 AppName 中添加 7 應用程式定義，如下所示：

CRUISE(1, "cruise"),
BACK(2, "back"),
REDDWARF_MUSIC(4, "長歌"),
REDDWARF_DICT(5, "紅矮星詞典"),
REDDWARF_ADMIN(6, "紅矮星后臺管理系統"),
MY_NEW_APP(7, "the new app name"),

將 替換MY_NEW_APP為您想要命名的任何內容。

標籤：爪哇 弹簧靴

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