更快的 xml 对象映射器将 java 对象错误地转换为 json？

Question

您好，我有一个包含对象数组的 json 数据文件。我正在读取 json 文件并将其转换为 java 对象的列表。但是，当我使用对象映射器将其转换为 json 文档时，我看到打印的值的精度后跟零。知道我该如何解决它。

下面是我的 json 数据文件。

[
  {
    "inventory": "SMS",
    "msg_text": "This is random text",
    "status": "ENROUTE",
    "@timestamp": "2019-09-02T03:26:26.770Z",
    "o_error": "",
    "flight_id": "92348fa1-ca6c-456a-b3b2-85fba2d2deed",
    "recipient": 420736408283,
    "account_id": "a56f7e14-20f9-40e6-90c6-10604140ac5f",
    "sender": 8800111,
    "submission_ts": 1567681407,
    "campaign_id": "6f2abca3-b46d-43f3-91be-3278a8dd7dc0",
    "nof_segments": 1,
    "@version": 1,
    "delivery_ts": 1558761537
  },
  {
    "inventory": "SMS",
    "msg_text": "This is random text",
    "status": "ENROUTE",
    "@timestamp": "2019-09-02T09:48:09.213Z",
    "o_error": "",
    "flight_id": "92348fa1-ca6c-456a-b3b2-85fba2d2deed",
    "recipient": 420736408283,
    "account_id": "a56f7e14-20f9-40e6-90c6-10604140ac5f",
    "sender": 8800111,
    "submission_ts": 1567681407,
    "campaign_id": "6f2abca3-b46d-43f3-91be-3278a8dd7dc0",
    "nof_segments": 1,
    "@version": 1,
    "delivery_ts": 1549246209
  }]

以下是读取文件的代码，将其转换为 json 对象并打印。

ObjectMapper objMapper = new ObjectMapper();
objMapper.registerModule(new JavaTimeModule());

objMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, 假);

List<MessageHistory> messageHistories = objMapper.readValue(getMessageHistoryResourceAsStream(),
                    objMapper.getTypeFactory().constructCollectionType(List.class, MessageHistory.class));
for (int i = 0; i < messageHistories.size(); i++) {
System.out.println(objMapper.writeValueAsString(messageHistories.get(i)));

}

输出低于

{"inventory":"SMS","msg_text":"This is random text","status":"ENROUTE","@timestamp":"2019-09-04T17:43:03.518Z","o_error":"","flight_id":"92348fa1-ca6c-456a-b3b2-85fba2d2deed","recipient":"420736408281","account_id":"a56f7e14-20f9-40e6-90c6-10604140ac5f","sender":"8800111","campaign_id":"6f2abca3-b46d-43f3-91be-3278a8dd7dc0","nof_segments":1,"@version":1,"submission_ts":1567681407.000000000,"delivery_ts":1562941055.000000000}
{"inventory":"SMS","msg_text":"This is random text","status":"ENROUTE","@timestamp":"2019-09-01T09:05:45.540Z","o_error":"","flight_id":"92348fa1-ca6c-456a-b3b2-85fba2d2deed","recipient":"420736408283","account_id":"a56f7e14-20f9-40e6-90c6-10604140ac5f","sender":"8800111","campaign_id":"6f2abca3-b46d-43f3-91be-3278a8dd7dc0","nof_segments":1,"@version":1,"submission_ts":1567681407.000000000,"delivery_ts":1558368683.000000000}

你可以看到 submission_ts 和 delivery_ts 有 .000000000 ..

下面是我的 MessageHistory.java 文件，我用它来将 json 数据绑定到对象。

import java.time.Instant;
import java.util.UUID;

import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonProperty;

public class MessageHistory {

    @JsonProperty("inventory")
    private String inventory;

    @JsonProperty("msg_text")
    private String messageText;

    @JsonProperty("status")
    private String status;

    @JsonProperty("@timestamp")
    private Instant timeStamp;

    @JsonProperty("o_error")
    private String error;

    @JsonProperty("flight_id")
    private UUID flightId;

    @JsonProperty("recipient")
    private String recipient;

    @JsonProperty("account_id")
    private UUID accountId;

    @JsonProperty("sender")
    private String sender;

    @JsonProperty("campaign_id")
    private UUID campaignId;

    @JsonProperty("nof_segments")
    private Integer segmentCount;

    @JsonProperty("@version")
    private Integer version;

    @JsonProperty("submission_ts")
    @JsonFormat(shape = JsonFormat.Shape.NUMBER_INT, timezone = "UTC")
    private Instant submissionTimeStamp;

    @JsonProperty("delivery_ts")
    @JsonFormat(shape = JsonFormat.Shape.NUMBER_INT, timezone = "UTC")
    private Instant deliveryTimeStamp;

    public String getInventory() {
        return inventory;
    }

    public void setInventory(String inventory) {
        this.inventory = inventory;
    }

    public String getMessageText() {
        return messageText;
    }

    public void setMessageText(String messageText) {
        this.messageText = messageText;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public Instant getTimeStamp() {
        return timeStamp;
    }

    public void setTimeStamp(Instant timeStamp) {
        this.timeStamp = timeStamp;
    }

    public String getError() {
        return error;
    }

    public void setError(String error) {
        this.error = error;
    }

    public UUID getFlightId() {
        return flightId;
    }

    public void setFlightId(UUID flightId) {
        this.flightId = flightId;
    }

    public String getRecipient() {
        return recipient;
    }

    public void setRecipient(String recipient) {
        this.recipient = recipient;
    }

    public String getSender() {
        return sender;
    }

    public void setSender(String sender) {
        this.sender = sender;
    }

    public UUID getAccountId() {
        return accountId;
    }

    public void setAccountId(UUID accountId) {
        this.accountId = accountId;
    }

    public UUID getCampaignId() {
        return campaignId;
    }

    public void setCampaignId(UUID campaignId) {
        this.campaignId = campaignId;
    }

    public Integer getSegmentCount() {
        return segmentCount;
    }

    public void setSegmentCount(Integer segmentCount) {
        this.segmentCount = segmentCount;
    }

    public Integer getVersion() {
        return version;
    }

    public void setVersion(Integer version) {
        this.version = version;
    }

    public Instant getSubmissionTimeStamp() {
        return submissionTimeStamp;
    }

    public void setSubmissionTimeStamp(Instant submissionTimeStamp) {
        this.submissionTimeStamp = submissionTimeStamp;
    }

    public Instant getDeliveryTimeStamp() {
        return deliveryTimeStamp;
    }

    public void setDeliveryTimeStamp(Instant deliveryTimeStamp) {
        this.deliveryTimeStamp = deliveryTimeStamp;
    }
}

我正在注释文件

@JsonProperty("submission_ts")
@JsonFormat(shape = JsonFormat.Shape.NUMBER_INT, timezone = "UTC")
private Instant submissionTimeStamp;

@JsonProperty("delivery_ts")
@JsonFormat(shape = JsonFormat.Shape.NUMBER_INT, timezone = "UTC")
private Instant deliveryTimeStamp;

非常感谢任何帮助解决为什么打印为 json 的对象在这两个字段上附加了 .000000 谢谢

Answer 1

您想禁用 WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS 功能。

来自文档：

Feature that controls whether numeric timestamp values are to be written using nanosecond timestamps (enabled) or not (disabled);

您可以在 ObjectMapper 中禁用它（适用于所有字段）：

ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JavaTimeModule());
mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
mapper.disable(SerializationFeature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS);

或在字段级别禁用它：

@JsonFormat(shape = Shape.NUMBER,
            without = Feature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS)
private Instant instant;

如果您打算在多个字段中使用此配置，您可能需要考虑 @JacksonAnnotationsInside，它允许您创建包含一个或多个 Jackson 注释的自定义注释：

@Retention(value = RUNTIME)
@JacksonAnnotationsInside
@JsonFormat(shape = Shape.NUMBER,
            without = Feature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS)
public @interface JsonTimestamp {

}

然后简单地使用新创建的注解：

@JsonTimestamp
private Instant instant;

更快的 xml 对象映射器将 java 对象错误地转换为 json？

Faster xml object mapper converting java object to json incorrectly?

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jackson

fasterxml