WIP

Author: jknack

modules/jooby-jsonrpc/src/main/java/io/jooby/internal/jsonrpc/DefaultJsonRpcInvoker.java

@@ -0,0 +1,27 @@
+/*
+ * Jooby https://jooby.io
+ * Apache License Version 2.0 https://jooby.io/LICENSE.txt
+ * Copyright 2014 Edgar Espina
+ */
+package io.jooby.internal.jsonrpc;
+
+import org.jspecify.annotations.NonNull;
+
+import io.jooby.Context;
+import io.jooby.SneakyThrows;
+import io.jooby.jsonrpc.JsonRpcInvoker;
+import io.jooby.jsonrpc.JsonRpcRequest;
+
+public class DefaultJsonRpcInvoker implements JsonRpcInvoker {
+  @Override
+  public <R> R invoke(
+      @NonNull Context ctx,
+      @NonNull JsonRpcRequest request,
+      SneakyThrows.@NonNull Supplier<R> action) {
+    try {
+      return action.get();
+    } catch (Throwable cause) {
+      throw SneakyThrows.propagate(cause);
+    }
+  }
+}

modules/jooby-jsonrpc/src/main/java/io/jooby/jsonrpc/JsonRpcInvoker.java

@@ -0,0 +1,29 @@
+/*
+ * Jooby https://jooby.io
+ * Apache License Version 2.0 https://jooby.io/LICENSE.txt
+ * Copyright 2014 Edgar Espina
+ */
+package io.jooby.jsonrpc;
+
+import java.util.Objects;
+
+import io.jooby.Context;
+import io.jooby.SneakyThrows;
+
+public interface JsonRpcInvoker {
+
+  Object invoke(Context ctx, JsonRpcRequest request, SneakyThrows.Supplier<Object> action)
+      throws Exception;
+
+  default JsonRpcInvoker then(JsonRpcInvoker next) {
+    Objects.requireNonNull(next, "next invoker is required");
+    return new JsonRpcInvoker() {
+      @Override
+      public Object invoke(
+          Context ctx, JsonRpcRequest request, SneakyThrows.Supplier<Object> action)
+          throws Exception {
+        return JsonRpcInvoker.this.invoke(ctx, request, () -> next.invoke(ctx, request, action));
+      }
+    };
+  }
+}

modules/jooby-jsonrpc/src/main/java/io/jooby/jsonrpc/JsonRpcModule.java

@@ -7,6 +7,7 @@
 
 import java.util.*;
 
+import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -50,6 +51,7 @@ public class JsonRpcModule implements Extension {
   private final Logger log = LoggerFactory.getLogger(JsonRpcService.class);
   private final Map<String, JsonRpcService> services = new HashMap<>();
   private final String path;
+  private @Nullable JsonRpcInvoker invoker;
 
   public JsonRpcModule(String path, JsonRpcService service, JsonRpcService... services) {
     this.path = path;
@@ -61,6 +63,15 @@ public JsonRpcModule(JsonRpcService service, JsonRpcService... services) {
     this("/rpc", service, services);
   }
 
+  public JsonRpcModule invoker(JsonRpcInvoker invoker) {
+    if (this.invoker != null) {
+      this.invoker = invoker.then(this.invoker);
+    } else {
+      this.invoker = invoker;
+    }
+    return this;
+  }
+
   private void registry(JsonRpcService service) {
     for (var method : service.getMethods()) {
       this.services.put(method, service);
@@ -121,20 +132,25 @@ private Object handle(Context ctx) {
       try {
         var targetService = services.get(fullMethod);
         if (targetService != null) {
-          var result = targetService.execute(ctx, request);
+          var result =
+              invoker == null
+                  ? targetService.execute(ctx, request)
+                  : invoker.invoke(ctx, request, () -> targetService.execute(ctx, request));
           // Spec: If the "id" is missing, it is a notification and no response is returned.
           if (request.getId() != null) {
-            responses.add(JsonRpcResponse.success(request.getId(), result));
+            if (result instanceof JsonRpcResponse jsonRpcResponse) {
+              responses.add(jsonRpcResponse);
+            } else {
+              responses.add(JsonRpcResponse.success(request.getId(), result));
+            }
           }
         } else {
           // Spec: -32601 Method not found
-          if (request.getId() != null) {
-            responses.add(
-                JsonRpcResponse.error(
-                    request.getId(),
-                    JsonRpcErrorCode.METHOD_NOT_FOUND,
-                    "Method not found: " + fullMethod));
-          }
+          responses.add(
+              JsonRpcResponse.error(
+                  request.getId(),
+                  JsonRpcErrorCode.METHOD_NOT_FOUND,
+                  "Method not found: " + fullMethod));
         }
       } catch (JsonRpcException cause) {
         log(ctx, request, cause);

modules/jooby-jsonrpc/src/main/java/io/jooby/jsonrpc/JsonRpcRequest.java

@@ -10,6 +10,8 @@
 import java.util.Iterator;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Represents a JSON-RPC 2.0 Request object, and simultaneously acts as an iterable container for
  * batch requests.
@@ -48,7 +50,7 @@ public class JsonRpcRequest implements Iterable<JsonRpcRequest> {
    * An identifier established by the Client that MUST contain a String, Number, or NULL value if
    * included. If it is not included it is assumed to be a notification.
    */
-  private Object id;
+  private @Nullable Object id;
 
   // --- Batch State ---
   private boolean batch;
@@ -80,11 +82,11 @@ public void setParams(Object params) {
     this.params = params;
   }
 
-  public Object getId() {
+  public @Nullable Object getId() {
     return id;
   }
 
-  public void setId(Object id) {
+  public void setId(@Nullable Object id) {
     this.id = id;
   }
 

modules/jooby-jsonrpc/src/main/java/io/jooby/jsonrpc/JsonRpcResponse.java

@@ -16,13 +16,14 @@
 public class JsonRpcResponse {
 
   private String jsonrpc = "2.0";
-  private Object result;
-  private ErrorDetail error;
-  private Object id;
+  private @Nullable Object result;
+  private @Nullable ErrorDetail error;
+  private @Nullable Object id;
 
   public JsonRpcResponse() {}
 
-  private JsonRpcResponse(Object id, Object result, ErrorDetail error) {
+  private JsonRpcResponse(
+      @Nullable Object id, @Nullable Object result, @Nullable ErrorDetail error) {
     this.id = id;
     this.result = result;
     this.error = error;
@@ -47,7 +48,7 @@ public static JsonRpcResponse success(Object id, Object result) {
    * @param data Additional data about the error.
    * @return A populated JsonRpcResponse.
    */
-  public static JsonRpcResponse error(Object id, JsonRpcErrorCode code, Object data) {
+  public static JsonRpcResponse error(@Nullable Object id, JsonRpcErrorCode code, Object data) {
     return new JsonRpcResponse(
         id, null, new ErrorDetail(code.getCode(), code.getMessage(), data(data)));
   }
@@ -67,27 +68,27 @@ public void setJsonrpc(String jsonrpc) {
     this.jsonrpc = jsonrpc;
   }
 
-  public Object getResult() {
+  public @Nullable Object getResult() {
     return result;
   }
 
-  public void setResult(Object result) {
+  public void setResult(@Nullable Object result) {
     this.result = result;
   }
 
   public @Nullable ErrorDetail getError() {
     return error;
   }
 
-  public void setError(ErrorDetail error) {
+  public void setError(@Nullable ErrorDetail error) {
     this.error = error;
   }
 
   public @Nullable Object getId() {
     return id;
   }
 
-  public void setId(Object id) {
+  public void setId(@Nullable Object id) {
     this.id = id;
   }
 

modules/jooby-mcp/src/main/java/io/jooby/internal/mcp/DefaultMcpInvoker.java

@@ -5,6 +5,7 @@
  */
 package io.jooby.internal.mcp;
 
+import org.jspecify.annotations.NonNull;
 import org.slf4j.LoggerFactory;
 
 import io.jooby.Jooby;
@@ -24,7 +25,7 @@ public DefaultMcpInvoker(Jooby application) {
 
   @SuppressWarnings("unchecked")
   @Override
-  public <R> R invoke(McpOperation operation, SneakyThrows.Supplier<R> action) {
+  public <R> R invoke(@NonNull McpOperation operation, SneakyThrows.@NonNull Supplier<R> action) {
     try {
       return action.get();
     } catch (McpError mcpError) {

modules/jooby-mcp/src/main/java/io/jooby/mcp/McpInvoker.java

@@ -5,6 +5,8 @@
  */
 package io.jooby.mcp;
 
+import java.util.Objects;
+
 import io.jooby.SneakyThrows;
 
 /**
@@ -69,9 +71,7 @@ public interface McpInvoker {
    * @return A composed invoker.
    */
   default McpInvoker then(McpInvoker next) {
-    if (next == null) {
-      return this;
-    }
+    Objects.requireNonNull(next, "next invoker is required");
     return new McpInvoker() {
       @Override
       public <R> R invoke(McpOperation operation, SneakyThrows.Supplier<R> action) {