Misleading NullPointerException when request parameter is not Serializable

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Apache Dubbo Component

Java SDK (apache/dubbo)

Descriptions

When calling a Dubbo service with a parameter that does not​ implement java.io.Serializable, the request fails with a confusing NullPointerException.

java.lang.NullPointerException: Cannot invoke "Object.hashCode()" because "key" is null at java.util.concurrent.ConcurrentHashMap.get(...) at org.apache.dubbo.rpc.support.GroupServiceKeyCache.getServiceKey(...) at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol.getInvoker(...)

Root Cause:​

The actual problem is that the entity class is not Serializable.

Adding implements Serializablefixes the issue immediately.

Expected Behavior:​

Dubbo should throw a clear exception (e.g. NotSerializableException) instead of an internal NPE.

Suggestion:​

Fail fast with a meaningful error message indicating which class is not serializable.

Related issues

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