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>

当前回答

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

其他回答

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

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。

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。

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());

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。