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

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;

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。

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)
  );
//...
}

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。