Kryo (Class cannot be created (missing no-arg constructor))

Sep 22, 2019

Kryo can serialize Java classes that do not implement Serializable in various ways, but deserializing certain objects, such as those without a no-argument constructor, can produce this error.

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Kryo can serialize Java classes that do not implement Serializable in various ways, but deserializing certain objects, such as those without a no-argument constructor, can produce this error:

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com.esotericsoftware.kryo.KryoException: Class cannot be created (missing no-arg constructor): org.apache.flink.cep.pattern.Pattern
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    at com.esotericsoftware.kryo.Kryo$DefaultInstantiatorStrategy.newInstantiatorOf(Kryo.java:1228)
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    at com.esotericsoftware.kryo.Kryo.newInstantiator(Kryo.java:1049)
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    at com.esotericsoftware.kryo.Kryo.newInstance(Kryo.java:1058)
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    at com.esotericsoftware.kryo.serializers.FieldSerializer.create(FieldSerializer.java:547)
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    at com.esotericsoftware.kryo.serializers.FieldSerializer.read(FieldSerializer.java:523)
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    at com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:657)

In this case, you can resolve it by using the org.objenesis.strategy.StdInstantiatorStrategy instantiation strategy in Kryo.