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2025-03-07 09:00:03

java8 LocalDate Jackson格式

对于java.util.Date

@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd/MM/yyyy")  
  private Date dateOfBirth;

然后在JSON请求中发送

{ {"dateOfBirth":"01/01/2000"} }

它的工作原理。

我应该如何为Java 8的LocalDate字段这样做??

我试着

@JsonDeserialize(using = LocalDateDeserializer.class)  
@JsonSerialize(using = LocalDateSerializer.class)  
private LocalDate dateOfBirth;

但是没有成功。

谁能告诉我正确的方法是什么?

下面是依赖关系

<dependency>
    <groupId>org.jboss.resteasy</groupId>
    <artifactId>jaxrs-api</artifactId>
     <version>3.0.9.Final</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-json-provider</artifactId>
    <version>2.4.2</version>
</dependency>
<dependency>
    <groupId>com.wordnik</groupId>
    <artifactId>swagger-annotations</artifactId>
    <version>1.3.10</version>
</dependency>

我从来没有能够让它简单地使用注释工作。为了让它工作，我为ObjectMapper创建了一个ContextResolver，然后添加了JSR310Module(更新:现在它是JavaTimeModule)，还有一个警告，需要将write-date-as-timestamp设置为false。更多信息请参见JSR310模块的文档。这是我使用的一个例子。

依赖

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
    <version>2.4.0</version>
</dependency>

注意:我遇到的一个问题是，由另一个依赖项引入的jackson注释版本使用了2.3.2版本，它抵消了jsr310所需的2.4版本。发生的事情是我得到了一个NoClassDefFound for ObjectIdResolver，这是一个2.4类。因此，我只需要排列包含的依赖项版本

ContextResolver

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JSR310Module;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;

@Provider
public class ObjectMapperContextResolver implements ContextResolver<ObjectMapper> {  
    private final ObjectMapper MAPPER;

    public ObjectMapperContextResolver() {
        MAPPER = new ObjectMapper();
        // Now you should use JavaTimeModule instead
        MAPPER.registerModule(new JSR310Module());
        MAPPER.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
    }

    @Override
    public ObjectMapper getContext(Class<?> type) {
        return MAPPER;
    }  
}

资源类

@Path("person")
public class LocalDateResource {

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public Response getPerson() {
        Person person = new Person();
        person.birthDate = LocalDate.now();
        return Response.ok(person).build();
    }

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    public Response createPerson(Person person) {
        return Response.ok(
                DateTimeFormatter.ISO_DATE.format(person.birthDate)).build();
    }

    public static class Person {
        public LocalDate birthDate;
    }
}

Test

旋度-v http://localhost:8080/api/person 结果:{“生日”:“2015-03-01”} curl -v -POST -H "Content-Type:application/json" -d "{\"birthDate\":\"2015-03-01\"}" http://localhost:8080/api/person 结果:2015-03-01

请参见此处了解JAXB解决方案。

更新

从Jackson 2.7版开始，JSR310Module已弃用。相反，您应该注册模块JavaTimeModule。它仍然是相同的依赖项。

2015-03-02 06:10:17 
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JavaTimeModule());
mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
2016-01-28 13:27:45

@JsonSerialize和@JsonDeserialize工作得很好。它们消除了导入额外jsr310模块的需要:

@JsonDeserialize(using = LocalDateDeserializer.class)  
@JsonSerialize(using = LocalDateSerializer.class)  
private LocalDate dateOfBirth;

反序列化器:

public class LocalDateDeserializer extends StdDeserializer<LocalDate> {

    private static final long serialVersionUID = 1L;

    protected LocalDateDeserializer() {
        super(LocalDate.class);
    }


    @Override
    public LocalDate deserialize(JsonParser jp, DeserializationContext ctxt)
            throws IOException, JsonProcessingException {
        return LocalDate.parse(jp.readValueAs(String.class));
    }

}

序列化器:

public class LocalDateSerializer extends StdSerializer<LocalDate> {

    private static final long serialVersionUID = 1L;

    public LocalDateSerializer(){
        super(LocalDate.class);
    }

    @Override
    public void serialize(LocalDate value, JsonGenerator gen, SerializerProvider sp) throws IOException, JsonProcessingException {
        gen.writeString(value.format(DateTimeFormatter.ISO_LOCAL_DATE));
    }
}
2016-08-02 21:52:18

在Spring Boot web应用程序中，使用Jackson和JSR 310版本“2.8.5”

compile "com.fasterxml.jackson.core:jackson-databind:2.8.5"
runtime "com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.8.5"

@JsonFormat的工作原理:

import com.fasterxml.jackson.annotation.JsonFormat;

@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd")
private LocalDate birthDate;
2016-11-15 12:37:51

只是更新了克里斯托弗的回答。

从2.6.0版本开始

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
    <version>2.9.0</version>
</dependency>

使用JavaTimeModule而不是JSR310Module(已弃用)。

@Provider
public class ObjectMapperContextResolver implements ContextResolver<ObjectMapper> {  
    private final ObjectMapper MAPPER;

    public ObjectMapperContextResolver() {
        MAPPER = new ObjectMapper();
        MAPPER.registerModule(new JavaTimeModule());
        MAPPER.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
    }

    @Override
    public ObjectMapper getContext(Class<?> type) {
        return MAPPER;
    }  
}

根据文档，新的JavaTimeModule使用相同的标准设置默认为序列化，不使用Timezone id，而只使用ISO-8601兼容的Timezone偏移量。

可以使用SerializationFeature改变行为。WRITE_DATES_WITH_ZONE_ID

2017-12-14 16:28:36

因为LocalDateSerializer默认将其转换为“[年，月，日]”(json数组)而不是“年-月-日”(json字符串)，并且因为我不想需要任何特殊的ObjectMapper设置(如果禁用SerializationFeature，您可以使LocalDateSerializer生成字符串)。WRITE_DATES_AS_TIMESTAMPS，但这需要额外的设置到您的ObjectMapper)，我使用以下:

进口:

import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;

代码:

// generates "yyyy-MM-dd" output
@JsonSerialize(using = ToStringSerializer.class)
// handles "yyyy-MM-dd" input just fine (note: "yyyy-M-d" format will not work)
@JsonDeserialize(using = LocalDateDeserializer.class)
private LocalDate localDate;

现在我可以使用new ObjectMapper()来读写我的对象，而不需要任何特殊的设置。

2018-08-03 20:21:02

最简单的解决方案(也支持反序列化和序列化)是

import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;

@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd/MM/yyyy")
@JsonDeserialize(using = LocalDateDeserializer.class)
@JsonSerialize(using = LocalDateSerializer.class)
private LocalDate dateOfBirth;

在项目中使用以下依赖项时。

Maven

<dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
   <version>2.9.7</version>
</dependency>
<dependency>
   <groupId>com.fasterxml.jackson.datatype</groupId>
   <artifactId>jackson-datatype-jsr310</artifactId>
   <version>2.9.7</version>
</dependency>

Gradle

compile "com.fasterxml.jackson.core:jackson-databind:2.9.7"
compile "com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.9.7"

不需要额外的ContextResolver、Serializer或Deserializer实现。

2018-11-11 17:52:16

https://stackoverflow.com/a/53251526/1282532是序列化/反序列化属性的最简单方法。对于这种方法，我有两个顾虑——在某种程度上违反了DRY原则，以及pojo和mapper之间的高耦合。

public class Trade {
    @JsonFormat(pattern = "yyyyMMdd")
    @JsonDeserialize(using = LocalDateDeserializer.class)
    @JsonSerialize(using = LocalDateSerializer.class)
    private LocalDate tradeDate;
    @JsonFormat(pattern = "yyyyMMdd")
    @JsonDeserialize(using = LocalDateDeserializer.class)
    @JsonSerialize(using = LocalDateSerializer.class)
    private LocalDate maturityDate;
    @JsonFormat(pattern = "yyyyMMdd")
    @JsonDeserialize(using = LocalDateDeserializer.class)
    @JsonSerialize(using = LocalDateSerializer.class)
    private LocalDate entryDate;
}

如果你有多个LocalDate字段的POJO，最好配置映射器而不是POJO。如果您使用的是ISO-8601值("2019-01-31")，可以简单到https://stackoverflow.com/a/35062824/1282532

如果你需要处理自定义格式，代码将是这样的:

ObjectMapper mapper = new ObjectMapper();
JavaTimeModule javaTimeModule = new JavaTimeModule();
javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyyMMdd")));
javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyyMMdd")));
mapper.registerModule(javaTimeModule);

逻辑只编写一次，它可以用于多个POJO

2019-03-04 14:01:56

在配置类中定义LocalDateSerializer和LocalDateDeserializer类，并通过JavaTimeModule将它们注册到ObjectMapper，如下所示:

@Configuration
public class AppConfig
{
@Bean
    public ObjectMapper objectMapper()
    {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(Include.NON_EMPTY);
        //other mapper configs
        // Customize de-serialization


        JavaTimeModule javaTimeModule = new JavaTimeModule();
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer());
        javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer());
        mapper.registerModule(javaTimeModule);

        return mapper;
    }

    public class LocalDateSerializer extends JsonSerializer<LocalDate> {
        @Override
        public void serialize(LocalDate value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            gen.writeString(value.format(Constant.DATE_TIME_FORMATTER));
        }
    }

    public class LocalDateDeserializer extends JsonDeserializer<LocalDate> {

        @Override
        public LocalDate deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
            return LocalDate.parse(p.getValueAsString(), Constant.DATE_TIME_FORMATTER);
        }
    }
}
2019-06-26 16:54:01

下面的注释对我来说效果很好。

不需要额外的依赖。

    @JsonProperty("created_at")
    @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSXXX")
    @JsonDeserialize(using = LocalDateTimeDeserializer.class)
    @JsonSerialize(using = LocalDateTimeSerializer.class)
    private LocalDateTime createdAt;
2019-11-28 07:29:02

到2020年和Jackson 2.10.1，不需要任何特殊的代码，只需要告诉Jackson你想要什么:

ObjectMapper objectMapper = new ObjectMapper();

// Register module that knows how to serialize java.time objects
// Provided by jackson-datatype-jsr310
objectMapper.registerModule(new JavaTimeModule());

// Ask Jackson to serialize dates as String (ISO-8601 by default)
objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);

这已经在这个答案中提到了，我添加了一个单元测试来验证功能:

import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import lombok.Data;
import org.junit.jupiter.api.Test;

import java.time.LocalDate;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class LocalDateSerializationTest {

    @Data
    static class TestBean {
        // Accept default ISO-8601 format
        LocalDate birthDate;
        // Use custom format
        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd/MM/yyyy")
        LocalDate birthDateWithCustomFormat;
    }

    @Test
    void serializeDeserializeTest() throws JsonProcessingException {
        ObjectMapper objectMapper = new ObjectMapper();

        // Register module that knows how to serialize java.time objects
        objectMapper.registerModule(new JavaTimeModule());

        // Ask Jackson to serialize dates as String (ISO-8601 by default)
        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);

        // The JSON string after serialization
        String json = "{\"birthDate\":\"2000-01-02\",\"birthDateWithCustomFormat\":\"03/02/2001\"}";

        // The object after deserialization
        TestBean object = new TestBean();
        object.setBirthDate(LocalDate.of(2000, 1, 2));
        object.setBirthDateWithCustomFormat(LocalDate.of(2001, 2, 3));

        // Assert serialization
        assertEquals(json, objectMapper.writeValueAsString(object));

        // Assert deserialization
        assertEquals(object, objectMapper.readValue(json, TestBean.class));
    }
}

TestBean使用Lombok为bean生成样板。

2020-01-13 01:10:46

到目前为止最简单和最短的:

@JsonFormat(pattern = "yyyy-MM-dd")
private LocalDate localDate;

@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
private LocalDateTime localDateTime;

Spring引导>= 2.2+不需要依赖

2020-03-13 09:09:31

如果你的请求包含一个这样的对象:

{
    "year": 1900,
    "month": 1,
    "day": 20
}

然后你可以使用:

data class DateObject(
    val day: Int,
    val month: Int,
    val year: Int
)
class LocalDateConverter : StdConverter<DateObject, LocalDate>() {
    override fun convert(value: DateObject): LocalDate {
        return value.run { LocalDate.of(year, month, day) }
    }
}

以上字段:

@JsonDeserialize(converter = LocalDateConverter::class)
val dateOfBirth: LocalDate

代码是在Kotlin中，但这当然也适用于Java。

2020-04-15 02:28:58 
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
@JsonSerialize(using = LocalDateTimeSerializer.class)
@JsonDeserialize(using = LocalDateTimeDeserializer.class)
private LocalDateTime createdDate;
2020-04-15 12:06:50

注释，而不使用额外的依赖项

@DateTimeFormat (pattern = "yyyy/MM/dd", iso = DateTimeFormat.ISO.DATE)
private LocalDate enddate;
2021-02-06 21:55:01

春季启动2.3.9。RELEASE，我刚刚注册了java时间模块，在POJO类中没有显式注释，具有LocalDate字段&它工作。

var objectMapper = new ObjectMapper();
objectMapper.registerModule(new JavaTimeModule());
2021-03-08 06:39:51

春天更容易些:

///...

@Configuration
public class ApplicationCtxBeans {
//....
    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper MAPPER = new ObjectMapper(); 
        MAPPER.registerModule(new JavaTimeModule()); // to handle LocalDateTime etc
        return MAPPER;
    }
//...
}

用法:

@Service
public class SomeService {
    
//...
    @Autowired
    ObjectMapper jsonMapper;
//...
  JsonNode node = jsonMapper.readTree(
    jsonMapper.writeValueAsString(instance_Of_Class_With_LocalDate_Fields)
  );
//...
}
2021-09-09 08:23:43

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