[英]Serialize JSON date format from ZonedDateTime to custom date format using ObjectMapper
[英]Deserialize JSON date format to ZonedDateTime using objectMapper
背景
{
"markdownPercentage": 20,
"currency": "SEK",
"startDate": "2019-07-25"
}
public class Markdown {
@JsonProperty("markdownPercentage")
@NotNull
private Integer markdownPercentage = 0;
@JsonProperty("currency")
@NotNull
private String currency = "";
@JsonFormat(
shape = Shape.STRING,
pattern = "yyyy-MM-dd"
)
@JsonProperty("startDate")
@NotNull
private ZonedDateTime startDate;
// Constructors, Getters, Setters etc.
}
問題
當應用程序嘗試將消息反序列化到對象時,它會引發以下異常
com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `java.time.ZonedDateTime` from String "2019-07-25": Failed to deserialize java.time.ZonedDateTime: (java.time.DateTimeException) Unable to obtain ZonedDateTime from TemporalAccessor: {},ISO resolved to 2019-07-25 of type java.time.format.Parsed
at [Source: (String)"{"styleOption":"so2_GreyMelange_1563966403695_1361997740","markdowns":[{"markdownPercentage":20,"currency":"SEK","startDate":"2019-07-25"},{"markdownPercentage":20,"currency":"NOK","startDate":"2019-07-25"},{"markdownPercentage":20,"currency":"CHF","startDate":"2019-07-25"}]}"; line: 1, column: 126] (through reference chain: com.bestseller.generated.interfacecontracts.kafkamessages.pojos.markdownScheduled.MarkdownScheduled["markdowns"]->java.util.ArrayList[0]->com.bestseller.generated.interfacecontracts.kafkamessages.pojos.markdownScheduled.Markdown["startDate"])
at com.fasterxml.jackson.databind.exc.InvalidFormatException.from(InvalidFormatException.java:67)
at com.fasterxml.jackson.databind.DeserializationContext.weirdStringException(DeserializationContext.java:1549)
at com.fasterxml.jackson.databind.DeserializationContext.handleWeirdStringValue(DeserializationContext.java:911)
at com.fasterxml.jackson.datatype.jsr310.deser.JSR310DeserializerBase._handleDateTimeException(JSR310DeserializerBase.java:80)
at com.fasterxml.jackson.datatype.jsr310.deser.InstantDeserializer.deserialize(InstantDeserializer.java:212)
at com.fasterxml.jackson.datatype.jsr310.deser.InstantDeserializer.deserialize(InstantDeserializer.java:50)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:127)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:286)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:245)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:27)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:127)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4013)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3004)
at com.bestseller.mps.functional.TestingConfiguration.test(TestingConfiguration.java:42)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.time.DateTimeException: Unable to obtain ZonedDateTime from TemporalAccessor: {},ISO resolved to 2019-07-25 of type java.time.format.Parsed
at java.base/java.time.ZonedDateTime.from(ZonedDateTime.java:566)
at com.fasterxml.jackson.datatype.jsr310.deser.InstantDeserializer.deserialize(InstantDeserializer.java:207)
... 35 more
Caused by: java.time.DateTimeException: Unable to obtain ZoneId from TemporalAccessor: {},ISO resolved to 2019-07-25 of type java.time.format.Parsed
at java.base/java.time.ZoneId.from(ZoneId.java:463)
at java.base/java.time.ZonedDateTime.from(ZonedDateTime.java:554)
... 36 more
當前代碼
我定義了以下 objectMapper
/**
* Date mapper.
*
* @return the {@link ObjectMapper}
*/
@Bean
public ObjectMapper objectMapper() {
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JavaTimeModule());
mapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd"));
return mapper;
}
題
我知道 POJO 中生成的 ZonedDateTime 需要一個源消息中不存在的“時間”元素。 我只能控制 objectMapper。 是否有任何可能的配置可以使這項工作?
筆記
如果反序列化的 POJO 中的時間元素“假定”為 startOfDay,即“00.00.00.000Z”,我很好
我只能控制
ObjectMapper
。 是否有任何可能的配置可以使這項工作?
只要您對時間和時區的默認值感到滿意,您就可以使用自定義解串器來解決它:
public class ZonedDateTimeDeserializer extends JsonDeserializer<ZonedDateTime> {
@Override
public ZonedDateTime deserialize(JsonParser jsonParser,
DeserializationContext deserializationContext)
throws IOException {
LocalDate localDate = LocalDate.parse(
jsonParser.getText(),
DateTimeFormatter.ISO_LOCAL_DATE);
return localDate.atStartOfDay(ZoneOffset.UTC);
}
}
然后將其添加到模塊並將該模塊注冊到您的ObjectMapper
實例:
SimpleModule module = new SimpleModule();
module.addDeserializer(ZonedDateTime.class, new ZonedDateTimeDeserializer());
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(module);
如果將解串器添加到模塊不適合您(從某種意義上說,此配置將應用於其他ZonedDateTime
實例),那么您可以依靠混合來定義解串器將應用於哪些字段。 首先定義一個mix-in接口,如下圖:
public interface MarkdownMixIn {
@JsonDeserialize(using = ZonedDateTimeDeserializer.class)
ZonedDateTime getDate();
}
然后將 mix-in 接口綁定到所需的類:
ObjectMapper mapper = new ObjectMapper();
mapper.addMixIn(Markdown.class, MarkdownMixIn.class);
遺憾的是,如果不將 POJO 的類型更改為 LocalDate,那將很困難。
我能想到的最接近的解決方案是為 Jackson 編寫一個自定義的JsonDeserializer
,這對於這種事情絕對不是一個好習慣。
您可以編寫自己的反序列化程序,如@cassiomolin答案中所示。 但也有另一種選擇。 在堆棧跟蹤中,我們有DeserializationContext.weirdStringException
方法,它允許我們為DeserializationProblemHandler
提供處理奇怪字符串值的方法。 見下面的例子:
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonFormat.Shape;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.deser.DeserializationProblemHandler;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import java.io.IOException;
import java.time.LocalDate;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.TimeZone;
public class AppJson {
public static void main(String[] args) throws IOException {
ObjectMapper mapper = new ObjectMapper();
// override default time zone if needed
mapper.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles"));
mapper.registerModule(new JavaTimeModule());
mapper.addHandler(new DeserializationProblemHandler() {
@Override
public Object handleWeirdStringValue(DeserializationContext ctxt, Class<?> targetType,
String valueToConvert, String failureMsg) {
LocalDate date = LocalDate.parse(valueToConvert, DateTimeFormatter.ISO_DATE);
return date.atStartOfDay(ctxt.getTimeZone().toZoneId());
}
});
String json = "{\"startDate\": \"2019-07-25\"}";
Markdown markdown = mapper.readValue(json, Markdown.class);
System.out.println(markdown);
}
}
上面的代碼打印:
Markdown{startDate=2019-07-25T00:00-07:00[America/Los_Angeles]}
問題:我想將日期從 json 解析為 java LocalDateTime/ZonedDateTime 對象。 ZonedDateTimeSerializer 存在,但 ZonedDateTimeDeserializer 不存在。 因此,我創建了一個自定義 ZonedDateTimeDeserializer。
public static final String ZONED_DATE_TIME_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSSz";
@Getter
@Setter
@JsonSerialize(using = ZonedDateTimeSerializer.class)
@JsonDeserialize(using = ZonedDateTimeDeserializer.class) // Doesn't exist, So I created a custom ZonedDateDeserializer utility class.
@JsonFormat(pattern = ZONED_DATE_TIME_FORMAT)
@JsonProperty("lastUpdated")
private ZonedDateTime lastUpdated;
解決方案:我最終得到了更簡單和更少的代碼行。
用於反序列化ZonedDateTime的實用程序類:
/**
* Custom {@link ZonedDateTime} deserializer.
*
* @param jsonParser for extracting the date in {@link String} format.
* @param deserializationContext for the process of deserialization a single root-level value.
* @return {@link ZonedDateTime} object of the date.
* @throws IOException throws I/O exceptions.
*/
public class ZonedDateTimeDeserializer extends JsonDeserializer<ZonedDateTime> {
@Override
public ZonedDateTime deserialize(JsonParser jsonParser, DeserializationContext deserializationContext)
throws IOException {
return ZonedDateTime.parse(jsonParser.getText(), DateTimeFormatter.ofPattern(ZONED_DATE_TIME_FORMAT));
}
}
如果您改用LocalDateTime會怎樣。 在這種情況下,它更容易,反序列化器和序列化器類已經提供給我們。 不需要上面定義的自定義實用程序類:
@Getter
@Setter
@JsonSerialize(using = LocalDateSerializer.class)
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonFormat(pattern = ZONED_DATE_TIME_FORMAT) //Specify the format you want: "yyyy-MM-dd'T'HH:mm:ss.SSS"
@JsonProperty("created")
private LocalDateTime created;
也有助於研究的其他鏈接: 導致此解決方案的想法
關鍵詞:json 格式 localDateTime zonedDateTime
不幸的是,默認情況下您不能將String Object
反序列化為ZonedDateTime
格式。 但是您可以通過兩種方式克服這個問題。
方式01
在POJO
類ZonedDateTime
類型更改為LocalDate
類型並將值作為字符串傳遞03-06-2012
方式02
但是如果您必須使用時區存儲日期和時間,那么您必須執行以下方法來克服
步驟 01
使用 DateTimeFormat 為ZonedDateTime
反序列化創建一個類
public class ZonedDateTimeDeserializer extends JsonDeserializer<ZonedDateTime> {
@Override
public ZonedDateTime deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
DateTimeFormatter dateTimeFormatter=DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm:ss z");
LocalDate localDate = LocalDate.parse(p.getText(),dateTimeFormatter);
return localDate.atStartOfDay(ZoneOffset.UTC);
}
}
步驟 02
在@JsonDeserialize
方法級別注釋的支持下,您必須將該 Deserialize 類與 POJO 類中的受影響字段一起使用。
@JsonDeserialize(using = ZonedDateTimeDeserializer.class)
private ZonedDateTime startDate;
步驟 03
在 ZonedDateTimeDeserializer 類中以上述格式將值作為字符串傳遞
"startDate" : "09-03-2003 10:15:00 Europe/Paris"
您需要將您的String
變量startDate
轉換為ZonedDateTimne
然后它將被轉換並保存到您的數據庫或其他任何地方。
由於即將到來的 json startDate 是字符串格式,並且您已經說過您不能更改 POJO,您需要在將其分配給private ZonedDateTime startDate;
之前對其進行轉換private ZonedDateTime startDate;
你可以像下面的例子一樣這樣做:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss a z");
ZonedDateTime dateTime = ZonedDateTime.parse("2019-03-27 10:15:30 AM +05:30", formatter);
System.out.println(dateTime);
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