对于java.util.Date,当我这样做
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd/MM/yyyy")
private Date dateOfBirth;
然后在我发送的JSON请求中
{ {"dateOfBirth":"01/01/2000"} }
有用。
我应该如何为Java 8的LocalDate字段执行此操作?
我试过了
@JsonDeserialize(using = LocalDateDeserializer.class)
@JsonSerialize(using = LocalDateSerializer.class)
private LocalDate dateOfBirth;
它没用。
有人可以让我知道这是正确的方法吗?
以下是依赖项
<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>
<dependency>
我从来没有能够使用注释使这个工作变得简单。为了使它工作,我为ContextResolver
创建了一个ObjectMapper
,然后我添加了JSR310Module
,还有一个警告,这是需要将write-date-as-timestamp设置为false。在the documentation for the JSR310 module查看更多信息。这是我用过的一个例子。
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jackson-annotation
版本被另一个依赖项引入,使用版本2.3.2,它取消了jsr310
所需的2.4。发生了什么事我得到了ObjectIdResolver
的NoClassDefFound,这是一个2.4级的。所以我只需要排列包含的依赖版本
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;
}
}
测试
curl -v http://localhost:8080/api/person
结果:{"birthDate":"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
有关JAXB解决方案,另请参见here。
JSR310Module
在Jackson的2.7版本中已被弃用。相反,您应该注册模块JavaTimeModule
。它仍然是相同的依赖。
@JsonSerialize和@JsonDeserialize对我来说很好。它们无需导入额外的jsr310模块:
@JsonDeserialize(using = LocalDateDeserializer.class)
@JsonSerialize(using = LocalDateSerializer.class)
private LocalDate dateOfBirth;
解串器:
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));
}
}
串行:
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));
}
}
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JavaTimeModule());
mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
对我来说很好。
在春季启动网络应用程序,“杰克逊”和“jsr310”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'有效:
import com.fasterxml.jackson.annotation.JsonFormat;
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd")
private LocalDate birthDate;
最简单的解决方案(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的
<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>
摇篮
compile "com.fasterxml.jackson.core:jackson-databind:2.9.7"
compile "com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.9.7"
不需要额外实现ContextResolver,Serializer或Deserializer。
由于LocalDateSerializer
默认将它变成“[年,月,日]”(一个json数组)而不是“年 - 月 - 日”(json字符串),因为我不想要任何特殊的ObjectMapper
设置(你可以让LocalDateSerializer
生成字符串,如果你禁用SerializationFeature.WRITE_DATES_AS_TIMESTAMPS
但需要额外设置你的ObjectMapper
),我使用以下内容:
进口:
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
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()
来读取和写入我的对象而无需任何特殊设置。
只是克里斯托弗回答的更新。
自版本2.6.0
<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(不建议使用)。
@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documentation,新的JavaTimeModule使用相同的标准设置来默认为不使用Timezone ID的序列化,而是仅使用符合ISO-8601的时区偏移。
可以使用SerializationFeature.WRITE_DATES_WITH_ZONE_ID更改行为
https://stackoverflow.com/a/53251526/1282532是序列化/反序列化属性的最简单方法。我对这种方法有两个顾虑 - 直到某些点违反DRY原则和pojo与mapper之间的高度耦合。
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;
}
如果您有多个LocalDate字段的POJO,最好配置mapper而不是POJO。如果您使用ISO-8601值(“2019-01-31”),它可以像https://stackoverflow.com/a/35062824/1282532一样简单
如果您需要处理自定义格式,代码将如下所示:
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);
逻辑只写一次,可以重复使用多个POJO
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);
}
}
}