我正在使用这三个库:Retrofit,jackson和jodatime,并且当它来自我的REST api时,我正在尝试反序列化我的对象,但是我不知道如何解决这个问题,这是REST API返回的json:
{
"establishment": "Gold Ball Confraria",
"idCardPayment": 0,
"paymentDate": "/Date(1461208761970+0000)/",
"total": 10
}
这就是我尝试反序列化我的对象的类:
public class PaymentHistoryItemApiResult {
@JsonProperty("total")
private double totalValue;
@JsonProperty("establishment")
private String establishmentName;
@JsonDeserialize(using = DateTimeDeserializer.class)
private DateTime paymentDate;
private long idCardPayment;
public PaymentHistoryItemApiResult() {
}
public PaymentHistoryItemApiResult(double totalValue, String establishmentName, DateTime paymentDate, long idCardPayment) {
this.totalValue = totalValue;
this.establishmentName = establishmentName;
this.paymentDate = paymentDate;
this.idCardPayment = idCardPayment;
}
... getters/setters
}
API 端点:
@GET("User.svc/{idUser}/payment/history")
Call<PaymentHistoryItemApiResult> getPaymentHistory(@Path("idUser") long idUser);
如何从单元测试调用它:
@Test
public void getPaymentHistoryTest(){
Response<PaymentHistoryItemApiResult> info = null;
try {
info = UserRequester.userRequester.getPaymentHistory(153).execute();
PaymentHistoryItemApiResult res = info.body();
Assert.assertNotNull(res);
} catch (IOException e) {
e.printStackTrace();
}
}
错误:
com.fasterxml.jackson.databind.JsonMappingException: Class com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer has no default (no arg) constructor
at [Source: java.io.InputStreamReader@525b461a; line: 1, column: 1]
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:251)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:269)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)
at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:477)
at com.fasterxml.jackson.databind.ObjectReader._findRootDeserializer(ObjectReader.java:1813)
at com.fasterxml.jackson.databind.ObjectReader._bindAndClose(ObjectReader.java:1570)
at com.fasterxml.jackson.databind.ObjectReader.readValue(ObjectReader.java:1183)
at retrofit2.converter.jackson.JacksonResponseBodyConverter.convert(JacksonResponseBodyConverter.java:32)
at retrofit2.converter.jackson.JacksonResponseBodyConverter.convert(JacksonResponseBodyConverter.java:23)
at retrofit2.ServiceMethod.toResponse(ServiceMethod.java:116)
at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:211)
at retrofit2.OkHttpCall.execute(OkHttpCall.java:174)
at br.com.soutsapp.user.souts.WCFClientTest.getPaymentHistoryTest(WCFClientTest.java:96)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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:78)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:212)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.IllegalArgumentException: Class com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer has no default (no arg) constructor
at com.fasterxml.jackson.databind.util.ClassUtil.createInstance(ClassUtil.java:594)
at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.deserializerInstance(DefaultDeserializationContext.java:234)
at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findDeserializerFromAnnotation(BasicDeserializerFactory.java:1772)
at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.constructSettableProperty(BeanDeserializerFactory.java:728)
at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.addBeanProps(BeanDeserializerFactory.java:506)
at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.buildBeanDeserializer(BeanDeserializerFactory.java:228)
at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer(BeanDeserializerFactory.java:143)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:406)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:352)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:264)
... 38 more
提前感谢,任何帮助将不胜感激。
第一视图分析:
代码中存在一些问题。您提供的时间看起来"/Date(1461208761970+0000)/"
不熟悉。您也有一些代码问题。您的构造函数无法与 joda 构造函数正确交谈
根源:
您的问题:
com.fasterxml.jackson.databind.JsonMappingException: Class com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer 没有 默认(无参数)构造函数
是从您的代码生成的:
at br.com.soutsapp.user.souts.WCFClientTest.getPaymentHistoryTest(WCFClientTest.java:96)
问题分析:
要将值反序列化为org.joda.time.DateTime
您必须定义@JsonDeserialize
因为杰克逊无法弄清楚 org.joda.time.DateTime
中使用什么方法/构造函数从字符串值初始化它。
解决方案 - 1:
您需要使用序列化和反序列化。您应该检查 jar 的可用性,并应将读取类型设置为 JSON。
您可以按照以下 3 个步骤操作。
- 您需要使用序列化和反序列化。您的日期模式应类似于 JsonFormat。
代码将是
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss")
@JsonSerialize(using = DateTimeSerializer.class)
@JsonDeserialize(using = DateTimeDeserializer.class)
private DateTime paymentDate;
确保您在类路径
jackson-datatype-joda
上具有 。默认情况下,将 SSM 配置更改为使用 JSON 格式(在默认内存缓存客户端定义):
<property name="defaultSerializationType" value="JSON" />
资源链接:
https://github.com/ragnor/simple-spring-memcached/issues/41
解决方案 - 2:
您也可以添加另一个构造函数。这可能会产生影响。
public PaymentHistoryItemApiResult() {
super();
}
资源链接:以下 2 个链接包含更多错误分析和解决方案
- 杰克逊例外 – 问题和解决方案
- Jackson – JsonMappingException (找不到类的序列化程序)
另一种解决方案:
如果您不想使用反序列化,则可以遵循详细信息:
@JsonDeserialize
期望一个具有无参数构造函数的JsonDeserializer
。最新版本的 DateTimeDeserializer 没有这样的构造函数。
如果您已修复格式,即 yourTimestamp 应该只是一个时间戳,那么您可以简单地将JodaModule
注册到 ObjectMapper
中。它将在内部对日期时间字段使用日期时间反序列化程序。您可以摆脱@JsonDeserialize注释。
mapper.registerModule(new JodaModule());
您需要添加jackson-datatype-joda
库。
资源链接:
- joda.time.DateTime 反序列化错误
用于空值序列化和反序列化
如果不想序列化 null 值,可以在序列化期间使用以下设置:
objectMapper.setSerializationInclusion(Include.NON_NULL);
对于反序列化,理想情况下,杰克逊应该能够处理序列化输出中的空值。
功劳归于@jackall
或者,您也可以在类中使用批注。
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(Include.NON_NULL)
我使用我的自定义反序列化:
@JsonDeserialize(using = MyDateTimeDeserializer.class)
private DateTime expiryTimeFirebaseCustomAccessToken;
带类:
import com.fasterxml.jackson.datatype.joda.cfg.FormatConfig;
import com.fasterxml.jackson.datatype.joda.cfg.JacksonJodaDateFormat;
import com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer;
import org.joda.time.DateTime;
/**
* Created by rudi on 3/28/18.
*/
public class MyDateTimeDeserializer extends DateTimeDeserializer {
public MyDateTimeDeserializer() {
super(DateTime.class, FormatConfig.DEFAULT_DATETIME_PARSER);
}
public MyDateTimeDeserializer(Class<?> cls, JacksonJodaDateFormat format) {
super(cls, format);
}
}
它对我有用...也许它可以做出贡献
只需使用 https://github.com/FasterXML/jackson-datatype-joda。它开箱即用,您不必使用其他注释将日期时间序列化/反序列化为 joda 时间对象。