无法在Mongodb中序列化LocalDate [英] Cannot serialize LocalDate in Mongodb

问题描述

我使用java 8 java.time.LocalDate来解析日期。

I am using the java 8 java.time.LocalDate to parse around dates.

但是尝试将一个LocalDate对象插入mongodb。我在java驱动程序中遇到错误：

But trying to insert a LocalDate object to mongodb. I get errors in the java driver:

private def writeData(measure: DBCollection, installation: Int, date: String, dates: ListBuffer[LocalDate],
                    values: ListBuffer[BigDecimal], validated: Boolean, overwrite: Boolean) {
  val timeValues: BasicDBList = new BasicDBList
  var i = 0
  while ( i < dates.size )  {
    val obj: BasicDBObject = new BasicDBObject("time", dates(i))
    obj.put("value", values(i).toString())
    timeValues.add(obj)
    i += 1
  }
  if ( debug ) System.out.println("Storedata: " + timeValues.toString) <-- error here

错误日志：

java.lang.RuntimeException：json无法序列化类型：类java.time.LocalDate
at com.mongodb.util.ClassMapBasedObjectSerializer.serialize（ClassMapBasedObjectSerializer.java:77）
at com .mongodb.util.JSONSerializers $ MapSerializer.serialize（JSONSerializ ers.java:317）
at com.mongodb.util.ClassMapBasedObjectSerializer.serialize（ClassMapBasedObjectSerializer.java:79）
at com.mongodb.util.JSONSerializers $ IterableSerializer.serialize（JSONSerializers.java:290）
at com.mongodb.util.ClassMapBasedObjectSerializer.serialize（ClassMapBasedObjectSerializer.java:79）
at com.mongodb.util.JSON.serialize（JSON.java:54）
at com.mongodb .util.JSON.serialize（JSON.java:40）
at com.mongodb.BasicDBList.toString（BasicDBList.java:38）
at web.MeasureAccess.writeData（MeasureAccess.scala：203）
at web.MeasureAccess.firstTime（MeasureAccess.scala：52）
at web.MeasureAccess $ .main（MeasureAccess.scala：262）
at web.MeasureAccess.main（MeasureAccess.scala）
at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）
at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）
at sun.reflect.DelegatingMethodAccessorImpl.i nvoke（DelegatingMethodAccessorImpl.java:43）
at java.lang.reflect.Method.invoke（Method.java:483）
at com.intellij.rt.execution.application.AppMain.main（AppMain。 java：134）

java.lang.RuntimeException: json can't serialize type : class java.time.LocalDate at com.mongodb.util.ClassMapBasedObjectSerializer.serialize(ClassMapBasedObjectSerializer.java:77) at com.mongodb.util.JSONSerializers$MapSerializer.serialize(JSONSerializers.java:317) at com.mongodb.util.ClassMapBasedObjectSerializer.serialize(ClassMapBasedObjectSerializer.java:79) at com.mongodb.util.JSONSerializers$IterableSerializer.serialize(JSONSerializers.java:290) at com.mongodb.util.ClassMapBasedObjectSerializer.serialize(ClassMapBasedObjectSerializer.java:79) at com.mongodb.util.JSON.serialize(JSON.java:54) at com.mongodb.util.JSON.serialize(JSON.java:40) at com.mongodb.BasicDBList.toString(BasicDBList.java:38) at web.MeasureAccess.writeData(MeasureAccess.scala:203) at web.MeasureAccess.firstTime(MeasureAccess.scala:52) at web.MeasureAccess$.main(MeasureAccess.scala:262) at web.MeasureAccess.main(MeasureAccess.scala) 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:483) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)

我使用的是mongo-java-driver-2.13.0-rc1.jar
Scala 2.11 .4
和java 1.8.0_25

I am using the mongo-java-driver-2.13.0-rc1.jar Scala 2.11.4 and java 1.8.0_25

为了完整性。

推荐答案

不幸的是，MongoDB驱动程序使用 java.util.Date 类型，请参阅文档这里

Unfortunately, the MongoDB driver uses the java.util.Date type, see the docs here

所以你必须先将LocalDate转换为Date实例，例如：

So you have to convert your LocalDate to a Date instance first, for example:

MongoClient mongoClient = new MongoClient("localhost", 27017);
DB db = mongoClient.getDB("test");
DBCollection coll = db.getCollection("testcol");

LocalDate ld = LocalDate.now();
Instant instant = ld.atStartOfDay().atZone(ZoneId.systemDefault()).toInstant();
Date date = Date.from(instant);

BasicDBObject doc = new BasicDBObject("localdate", date);
coll.insert(doc);

我建议使用像 Morphia 或 Jongo 包装MongoDB驱动程序，因为您可以注册全局映射器以隐式执行这些转换，以便您可以在域模型中使用LocalDate等

I would suggest using something like Morphia or Jongo to wrap the MongoDB driver though, as you can register global mappers to implicitly do these conversions on the fly, so that you can use LocalDate, etc, in your domain model

这篇关于无法在Mongodb中序列化LocalDate的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！