title: Netty Decoding failed DefaultFullHttpRequest
body: <p>I am currently developing using spring boot webflux. I am using websocket clients and APIs clients, but this error occurs a few hours after deployment. I couldn't figure out where this error was coming from. Where does this problem come from?</p>
  <p>The error log is as below.</p>
  <pre><code>[reactor-http-epoll-2] r.n.http.server.HttpServerOperations     : [9c0c3ede, L:/172.25.0.8:8080 - R:/94.232.43.63:34534] Decoding failed: DefaultFullHttpRequest(decodeResult: failure(java.lang.IllegalArgumentException: text is empty (possibly HTTP/0.9)), version: HTTP/1.0, content: UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeHeapByteBuf(ridx: 0, widx: 0, cap: 0))
  GET /bad-request HTTP/1.0 :
  
  java.lang.IllegalArgumentException: text is empty (possibly HTTP/0.9)
          at io.netty.handler.codec.http.HttpVersion.valueOf(HttpVersion.java:65) ~[netty-codec-http-4.1.72.Final.jar:4.1.72.Final]
          at io.netty.handler.codec.http.HttpRequestDecoder.createMessage(HttpRequestDecoder.java:126) ~[netty-codec-http-4.1.72.Final.jar:4.1.72.Final]
          at io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:273) ~[netty-codec-http-4.1.72.Final.jar:4.1.72.Final]
          at io.netty.handler.codec.http.HttpServerCodec$HttpServerRequestDecoder.decode(HttpServerCodec.java:140) ~[netty-codec-http-4.1.72.Final.jar:4.1.72.Final]
          at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:507) ~[netty-codec-4.1.72.Final.jar:4.1.72.Final]
          at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:446) ~[netty-codec-4.1.72.Final.jar:4.1.72.Final]
  </code></pre>
  <p>Sometimes broken characters are also found along with the sentence 'text is empty'.
  If this is an encoding issue, how should I set it up?</p>