java - 无法反序列化模型实例。PublisheDataList 超出 START_ARRAY token

Question

我正在尝试使用 jackson api 解析 json，并包含以下详细信息。但我收到错误。请查找以下代码和堆栈跟踪详细信息。

JSON

[{"id":1001,"cyPerReffe":1200,"distPercentage":"0"},{"id":1002,"cyPerReffe":1000,"distPercentage":"10"},{"id":1003,"cyPerReffe":800,"distPercentage":"20"},{"id":1004,"cyPerReffe":750,"distPercentage":"10"},{"id":1005,"cyPerReffe":700,"distPercentage":"10"},{"id":1006,"cyPerReffe":650,"distPercentage":"10"},{"id":1007,"cyPerReffe":600,"distPercentage":"20"},{"id":1008,"cyPerReffe":300,"distPercentage":"5"},{"id":1009,"cyPerReffe":333,"distPercentage":"7"},{"id":1010,"cyPerReffe":"32","distPercentage":"8"}]

Controller 类

ObjectMapper mapper = new ObjectMapper();   mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
PublisheDataList publisheDataList = mapper.convertValue(json, PublisheDataList.class);

下面的类(class)是我的 Bean 类(class)。PublisheData.java

private Long id;
private Long cyPerReffe;
private String distPercentage;
//    with setter and getters

PublisheDataList.java

List<PublisheData> publisheDataList;
//with setter and getters

我收到以下错误。

java.lang.IllegalArgumentException: Can not deserialize instance of models.PublisheDataList out of START_ARRAY token
 at [Source: N/A; line: -1, column: -1]
        at org.codehaus.jackson.map.ObjectMapper._convert(ObjectMapper.java:2502)
        at org.codehaus.jackson.map.ObjectMapper.convertValue(ObjectMapper.java:2468)
        at controllers.RYSController.publishReferenceYield(RYSController.java:79)
        at Routes$$anonfun$routes$1$$anonfun$applyOrElse$22$$anonfun$apply$62.apply(routes_routing.scala:318)
        at Routes$$anonfun$routes$1$$anonfun$applyOrElse$22$$anonfun$apply$62.apply(routes_routing.scala:318)
        at play.core.Router$HandlerInvoker$$anon$6$$anon$2.invocation(Router.scala:175)
        at play.core.Router$Routes$$anon$1.invocation(Router.scala:355)
        at play.core.j.JavaAction$$anon$1.call(JavaAction.scala:50)
        at play.GlobalSettings$1.call(GlobalSettings.java:63)
        at play.core.j.JavaAction$$anon$2.apply(JavaAction.scala:80)
        at play.core.j.JavaAction$$anon$2.apply(JavaAction.scala:79)
        at play.libs.F$Promise$PromiseActor.onReceive(F.java:425)
        at akka.actor.UntypedActor$$anonfun$receive$1.applyOrElse(UntypedActor.scala:159)
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:425)
        at akka.actor.ActorCell.invoke(ActorCell.scala:386)
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:230)
        at akka.dispatch.Mailbox.run(Mailbox.scala:212)
        at akka.dispatch.ForkJoinExecutorConfigurator$MailboxExecutionTask.exec(AbstractDispatcher.scala:502)
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:262)
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:975)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1478)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:104)
Caused by: org.codehaus.jackson.map.JsonMappingException: Can not deserialize instance of models.PublisheDataList out of START_ARRAY token
 at [Source: N/A; line: -1, column: -1]
        at org.codehaus.jackson.map.JsonMappingException.from(JsonMappingException.java:163)
        at org.codehaus.jackson.map.deser.StdDeserializationCenter code hereontext.mappingException(StdDeserializationContext.java:219)
        at org.codehaus.jackson.map.deser.StdDeserializationContext.mappingException(StdDeserializationContext.java:212)
        at org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromArray(BeanDeserializer.java:875)
        at org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java:597)
        at org.codehaus.jackson.map.ObjectMapper._readValue(ObjectMapper.java:2704)
        at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1315)
        at org.codehaus.jackson.map.ObjectMapper._convert(ObjectMapper.java:2498)
        ... 21 more

Answer 1

您不需要 PublisheDataList 中间类来反序列化为 Collection，请尝试直接使用映射器反序列化

List<PublisheData> publisheDataList = mapper.convertValue(json, mapper.getTypeFactory().constructCollectionType(List.class, PublisheData.class));