help request: ext-plugin(java) error with multipart/form-data?

### Description

apisix-java-plugin-runner version is 0.4.0

request Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryedcKdnGDWD6rJDcu

payload is
------WebKitFormBoundaryedcKdnGDWD6rJDcu
Content-Disposition: form-data; name="file"; filename="test.xlsx"
Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

------WebKitFormBoundaryedcKdnGDWD6rJDcu
Content-Disposition: form-data; name="age"

20
------WebKitFormBoundaryedcKdnGDWD6rJDcu--

but ext 503 error occured..

error.log is below.. is that library issue?

pls check this log
```
2023/12/22 09:46:12 [warn] 52461#52461: *63 [lua] init.lua:956: 2023-12-22 09:46:12.590 ERROR 52473 --- [tLoopGroup-34-4] o.a.a.p.r.h.RpcCallHandler : handle request error:

java.lang.IndexOutOfBoundsException: null
at java.nio.Buffer.checkIndex(Buffer.java:687) ~[?:?]
at java.nio.DirectByteBuffer.get(DirectByteBuffer.java:269) ~[?:?]
at io.github.api7.A6.ExtraInfo.Resp.result(Resp.java:18) ~[A6-0.6.0-RELEASE.jar!/:?]
at org.apache.apisix.plugin.runner.ExtraInfoResponse.getResult(ExtraInfoResponse.java:41) ~[apisix-runner-plugin-sdk-0.4.0.jar!/:0.4.0]
at org.apache.apisix.plugin.runner.handler.RpcCallHandler.handleExtraInfo(RpcCallHandler.java:218) ~[apisix-runner-core-0.4.0.jar!/:0.4.0]
at org.apache.apisix.plugin.runner.handler.RpcCallHandler.channelRead0(RpcCallHandler.java:92) ~[apisix-runner-core-0.4.0.jar!/:0.4.0]
at org.apache.apisix.plugin.runner.handler.RpcCallHandler.channelRead0(RpcCallHandler.java:54) ~[apisix-runner-core-0.4.0.jar!/:0.4.0]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at org.apache.apisix.plugin.runner.handler.PrepareConfHandler.channelRead0(PrepareConfHandler.java:57) ~[apisix-runner-core-0.4.0.jar!/:0.4.0]
at org.apache.apisix.plugin.runner.handler.PrepareConfHandler.channelRead0(PrepareConfHandler.java:45) ~[apisix-runner-core-0.4.0.jar!/:0.4.0]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
2023/12/22 09:46:12 [warn] 52461#52461: *63 [lua] init.lua:956: y.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.handler.logging.LoggingHandler.channelRead(LoggingHandler.java:280) ~[netty-handler-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) ~[netty-transport-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800) ~[netty-transport-classes-epoll-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.epoll.EpollDomainSocketChannel$EpollDomainUnsafe.epollInReady(EpollDomainSocketChannel.java:138) ~[netty-transport-classes-epoll-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:487) ~[netty-transport-classes-epoll-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:385) ~[netty-transport-classes-epoll-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.78.Final.jar!/:4.1.78.Final]
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.78.Final.jar!/:4.1.78.Final]
at java.lang.Thread.run(Thread.java:829) ~[?:?]

, context: ngx.timer
2023/12/22 09:46:12 [warn] 52461#52461: *63 [lua] init.lua:956: 2023-12-22 09:46:12.597 WARN 52473 --- [tLoopGroup-34-4] o.a.a.p.r.h.PayloadDecoder : receive unsupported type: -4
, context: ngx.timer
2023/12/22 09:46:12 [warn] 52461#52461: *63 [lua] init.lua:956: 2023-12-22 09:46:12.605 WARN 52473 --- [tLoopGroup-34-4] o.a.a.p.r.h.PayloadDecoder : receive unsupported type: -72
, context: ngx.timer
2023/12/22 09:46:12 [error] 52455#52455: *6011569 [lua] init.lua:884: phase_func(): failed to receive RPC_HTTP_REQ_CALL: service unavailable, client:
2023/12/22 09:46:12 [warn] 52455#52455: *6011569 [lua] plugin.lua:1102: run_plugin(): ext-plugin-pre-req exits with http status code 503,
```
### Environment

- APISIX version (run `apisix version`): 3.4.1
- Operating system (run `uname -a`):
- OpenResty / Nginx version (run `openresty -V` or `nginx -V`):
- etcd version, if relevant (run `curl http://127.0.0.1:9090/v1/server_info`):
- APISIX Dashboard version, if relevant:
- Plugin runner version, for issues related to plugin runners:
- LuaRocks version, for installation issues (run `luarocks --version`):