Package org.mockserver.netty.http3

Class GrpcHttp3Adapter

java.lang.Object

org.mockserver.netty.http3.GrpcHttp3Adapter

public final class GrpcHttp3Adapter
extends Object

Adapter that bridges gRPC request/response framing for the HTTP/3 path.

Reuses the existing GrpcFrameCodec, GrpcProtoDescriptorStore, and GrpcJsonMessageConverter from mockserver-core -- no logic is duplicated. The adapter handles:

• Inbound: detecting gRPC content-type, decoding the 5-byte length-prefixed gRPC frame(s) from the request body, converting protobuf to JSON via the descriptor store, and tagging the request with x-grpc-service / x-grpc-method so the response path can re-encode.
• Outbound: converting the matched response's JSON body back to gRPC-framed protobuf, building the initial HTTP/3 HEADERS frame (without grpc-status), the DATA frame (gRPC framed body), and a separate trailing HEADERS frame with grpc-status/grpc-message -- the correct wire framing that gRPC clients expect over HTTP/3.

This class is stateless and thread-safe; all state is passed via method parameters.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	GrpcHttp3Adapter.GrpcResponseParts	Holds the parts of a gRPC response for HTTP/3 framing: the gRPC-framed body bytes, the grpc-status value, and an optional grpc-message.

Method Summary

Modifier and Type	Method	Description
static io.netty.handler.codec.http3.DefaultHttp3DataFrame	buildDataFrame(byte[] grpcFrameBytes)	Build an HTTP/3 DATA frame from gRPC-framed bytes.
static io.netty.handler.codec.http3.DefaultHttp3HeadersFrame	buildInitialHeadersFrame()	Build the initial HTTP/3 HEADERS frame for a gRPC response.
static io.netty.handler.codec.http3.DefaultHttp3HeadersFrame	buildTrailersOnlyFrame(String grpcStatus, String grpcMessage)	Build a "trailers-only" HTTP/3 HEADERS frame that combines :status, content-type, and grpc-status/grpc-message in a single HEADERS frame (no DATA frame follows).
static io.netty.handler.codec.http3.DefaultHttp3HeadersFrame	buildTrailingHeadersFrame(String grpcStatus, String grpcMessage)	Build the trailing HTTP/3 HEADERS frame for a gRPC response.
static GrpcHttp3Adapter.GrpcResponseParts	errorResponse(GrpcStatusMapper.GrpcStatusCode statusCode, String message)	Build an error response (trailers-only pattern) for gRPC over HTTP/3.
static boolean	isGrpcRequest(String contentType)	Detect whether the given content-type indicates a gRPC request.
static HttpRequest	transformGrpcRequest(HttpRequest request, GrpcProtoDescriptorStore descriptorStore)	Transform a gRPC request for the MockServer matching pipeline: decode the gRPC length-prefixed message(s), convert protobuf to JSON via the descriptor store, and tag the request with service/method markers.
static GrpcHttp3Adapter.GrpcResponseParts	transformGrpcResponse(HttpResponse response, String serviceName, String methodName, GrpcProtoDescriptorStore descriptorStore)	Convert the response from the matching pipeline back to a gRPC-framed response.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

isGrpcRequest

public static boolean isGrpcRequest(String contentType)

Detect whether the given content-type indicates a gRPC request. Delegates to GrpcStatusMapper.isGrpcContentType(String).

transformGrpcRequest

public static HttpRequest transformGrpcRequest(HttpRequest request,
 GrpcProtoDescriptorStore descriptorStore)

Transform a gRPC request for the MockServer matching pipeline: decode the gRPC length-prefixed message(s), convert protobuf to JSON via the descriptor store, and tag the request with service/method markers.

Parameters:

request - the raw HttpRequest with gRPC-framed binary body

descriptorStore - the gRPC proto descriptor store

Returns:

a transformed HttpRequest with a JSON body suitable for matching

Throws:

GrpcException - if the gRPC path or framing is invalid

transformGrpcResponse

public static GrpcHttp3Adapter.GrpcResponseParts transformGrpcResponse(HttpResponse response,
 String serviceName,
 String methodName,
 GrpcProtoDescriptorStore descriptorStore)

Convert the response from the matching pipeline back to a gRPC-framed response. Encodes the JSON body to protobuf, wraps it in a gRPC length-prefixed frame, and determines the grpc-status.

Parameters:

response - the matched HttpResponse (JSON body, grpc-status-name header)

serviceName - the gRPC service name from the original request

methodName - the gRPC method name from the original request

descriptorStore - the gRPC proto descriptor store

Returns:

a GrpcHttp3Adapter.GrpcResponseParts with the initial headers, body bytes, and trailing headers

errorResponse

public static GrpcHttp3Adapter.GrpcResponseParts errorResponse(GrpcStatusMapper.GrpcStatusCode statusCode,
 String message)

Build an error response (trailers-only pattern) for gRPC over HTTP/3. Used when gRPC request processing fails before matching.

Parameters:

statusCode - the gRPC status code

message - the error message

Returns:

a GrpcHttp3Adapter.GrpcResponseParts with no body and the error status

buildInitialHeadersFrame

public static io.netty.handler.codec.http3.DefaultHttp3HeadersFrame buildInitialHeadersFrame()

Build the initial HTTP/3 HEADERS frame for a gRPC response. Contains :status=200 and content-type=application/grpc but NOT grpc-status (which belongs in the trailing HEADERS frame).

buildTrailingHeadersFrame

public static io.netty.handler.codec.http3.DefaultHttp3HeadersFrame buildTrailingHeadersFrame(String grpcStatus,
 String grpcMessage)

Build the trailing HTTP/3 HEADERS frame for a gRPC response. Contains grpc-status and optionally grpc-message. No pseudo-headers (no :status) because this is a trailing HEADERS frame.

buildDataFrame

public static io.netty.handler.codec.http3.DefaultHttp3DataFrame buildDataFrame(byte[] grpcFrameBytes)

Build an HTTP/3 DATA frame from gRPC-framed bytes. Returns null if the frame bytes are null or empty.

buildTrailersOnlyFrame

public static io.netty.handler.codec.http3.DefaultHttp3HeadersFrame buildTrailersOnlyFrame(String grpcStatus,
 String grpcMessage)

Build a "trailers-only" HTTP/3 HEADERS frame that combines :status, content-type, and grpc-status/grpc-message in a single HEADERS frame (no DATA frame follows). This is used for error responses where there is no message body.