反序列化期間異常：“ java.lang.ClassCastException：類java.lang.Enum不是枚舉”

Question

我試圖解決在用傑克遜對EnumSet進行反序列化時遇到的問題。

我有像創建的EnumSet

EnumSet set = EnumSet.of(TestEnum.Value1, TestEnum.Value2, TestEnum.Value3);

並在反序列化期間獲得以下異常：

java.lang.ClassCastException: class java.lang.Enum not an enum
    at java.util.EnumSet.noneOf(EnumSet.java:93)
    at com.fasterxml.jackson.databind.deser.std.EnumSetDeserializer.constructSet(EnumSetDeserializer.java:123)
    at com.fasterxml.jackson.databind.deser.std.EnumSetDeserializer.deserialize(EnumSetDeserializer.java:88)
    at com.fasterxml.jackson.databind.deser.std.EnumSetDeserializer.deserialize(EnumSetDeserializer.java:18)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2575)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:1805)
    at com.easycompany.providers.serialization.impl.jackson.base.JacksonSerializationProviderBase.readString(JacksonSerializationProviderBase.java:339)
    at com.easycompany.tests.serialization.base.ReadWriteStringTestBase.read(ReadWriteStringTestBase.java:33)
    at com.easycompany.tests.serialization.base.ReadWriteStringTestBase.action(ReadWriteStringTestBase.java:28)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:30)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:76)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:195)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:63)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

誰能幫我解決該問題的方法？

由我解決 ：如果感興趣，請閱讀下面的答案。

Answer 1

我已經自己找到了解決方案。 問題是，在方法EnumSet.noneOf()需要傳遞具體的枚舉類型（在我的例子中為TestEnum），但是我通過一堆通用函數對其進行調用，結果在代碼中它只知道它需要構造枚舉，但不知道它應該約束哪個枚舉。 使用具有有效類型引用的參數的傑克遜閱讀器可以解決此問題。