Do not reject UNKNOWN HttpMethod

core/src/main/java/com/linecorp/armeria/server/Http1RequestDecoder.java

@@ -197,11 +197,9 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
                                                       cfg, scheme.toString(), reqTarget);
                     // Do not accept unsupported methods.
                     final HttpMethod method = headers.method();
-                    switch (method) {
-                        case CONNECT:
-                        case UNKNOWN:
-                            fail(id, headers, HttpStatus.METHOD_NOT_ALLOWED, "Unsupported method", null);
-                            return;
+                    if (method == HttpMethod.CONNECT) {
+                        fail(id, headers, HttpStatus.METHOD_NOT_ALLOWED, "Unsupported method", null);
+                        return;
                     }
 
                     // Do not accept the request path '*' for a non-OPTIONS request.

core/src/main/java/com/linecorp/armeria/server/Http2RequestDecoder.java

@@ -148,18 +148,13 @@ public void onHeadersRead(ChannelHandlerContext ctx, int streamId, Http2Headers
                                                             scheme.toString(), cfg, reqTarget);
 
             // Reject a request with an unsupported method.
-            switch (method) {
-                case CONNECT:
-                    // Accept a CONNECT request only when it has a :protocol header, as defined in:
-                    // https://datatracker.ietf.org/doc/html/rfc8441#section-4
-                    if (!nettyHeaders.contains(HttpHeaderNames.PROTOCOL)) {
-                        writeUnsupportedMethodResponse(streamId, headers);
-                        return;
-                    }
-                    break;
-                case UNKNOWN:
+            if (method == HttpMethod.CONNECT) {
+                // Accept a CONNECT request only when it has a :protocol header, as defined in:
+                // https://datatracker.ietf.org/doc/html/rfc8441#section-4
+                if (!nettyHeaders.contains(HttpHeaderNames.PROTOCOL)) {
                     writeUnsupportedMethodResponse(streamId, headers);
                     return;
+                }
             }
 
             // Do not accept the request path '*' for a non-OPTIONS request.

tomcat10/src/main/java/com/linecorp/armeria/server/tomcat/TomcatService.java

@@ -532,8 +532,7 @@ private Request convertRequest(ServiceRequestContext ctx, String mappedPath, Agg
         coyoteReq.protocol().setString(ctx.sessionProtocol().isMultiplex() ? "HTTP/2.0" : "HTTP/1.1");
 
         // Set the method.
-        final HttpMethod method = req.method();
-        coyoteReq.method().setString(method.name());
+        coyoteReq.method().setString(req.headers().get(HttpHeaderNames.METHOD));
 
         // Set the request URI.
         final byte[] uriBytes = mappedPath.getBytes(StandardCharsets.US_ASCII);