[BUG]枚举类型为null时，反序列化异常

[VirensCn]

问题描述

简要描述您碰到的问题。

环境信息

请填写以下信息：

• OS信息： [e.g.：CentOS 8.4.2105 4Core 3.10GHz 16 GB]
• JDK信息： [e.g.：Openjdk 1.8.0_312]
• 版本信息：[e.g.：Fastjson2 2.x.x]

重现步骤

如何操作可以重现该问题：

1. 参数类型为枚举类
2. 使用JSONB（dubbo环境）
3. 参数传null
4. 就会出现下面无法解析的异常

2023-04-20 09:16:00.581 [WARN ] org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation:  [DUBBO] Decode rpc invocation failed: string value not support input INT32 0 offset 1/1, dubbo version: 3.2.0, current host: 172.20.0.4, error code: 4-20. This may be caused by , go to https://dubbo.apache.org/faq/4/20 to find instructions. 
com.alibaba.fastjson2.JSONException: string value not support input INT32 0 offset 1/1
	at com.alibaba.fastjson2.JSONReaderJSONB.readValueHashCode(JSONReaderJSONB.java:1807) ~[fastjson2-2.0.28.jar:?]
	at com.alibaba.fastjson2.reader.ObjectReaderImplEnum.readJSONBObject(ObjectReaderImplEnum.java:135) ~[fastjson2-2.0.28.jar:?]
	at com.alibaba.fastjson2.JSONB.parseObject(JSONB.java:535) ~[fastjson2-2.0.28.jar:?]
	at org.apache.dubbo.common.serialize.fastjson2.FastJson2ObjectInput.readObject(FastJson2ObjectInput.java:118) ~[dubbo-serialization-fastjson2-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.drawArgs(DecodeableRpcInvocation.java:261) ~[dubbo-rpc-dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:162) ~[dubbo-rpc-dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:102) ~[dubbo-rpc-dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.dubbo.DubboCodec.decodeBody(DubboCodec.java:173) ~[dubbo-rpc-dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:138) ~[dubbo-remoting-api-3.2.0.jar:3.2.0]
	at org.apache.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:92) ~[dubbo-remoting-api-3.2.0.jar:3.2.0]
	at org.apache.dubbo.rpc.protocol.dubbo.DubboCountCodec.decode(DubboCountCodec.java:60) ~[dubbo-rpc-dubbo-3.2.0.jar:3.2.0]
	at org.apache.dubbo.remoting.transport.netty4.NettyCodecAdapter$InternalDecoder.decode(NettyCodecAdapter.java:103) ~[dubbo-remoting-netty4-3.2.0.jar:3.2.0]
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:529) ~[netty-codec-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:468) ~[netty-codec-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290) ~[netty-codec-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.91.Final.jar:4.1.91.Final]
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.91.Final.jar:4.1.91.Final]
	at java.lang.Thread.run(Thread.java:833) ~[?:?]

期待的正确结果

对您期望发生的结果进行清晰简洁的描述。

相关日志输出

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附加信息

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[wenshao]

https://github.com/alibaba/fastjson2/releases/tag/2.0.29
请用新版本