Refactor webmvc to use the new Handler

spring-graphql-common/build.gradle

@@ -4,7 +4,7 @@ apply plugin: 'java-library'
 
 dependencies {
     implementation "org.springframework:spring-web:$springVersion"
-    implementation 'io.projectreactor:reactor-core:3.3.8.RELEASE'
+    api 'io.projectreactor:reactor-core:3.3.8.RELEASE'
     api "com.graphql-java:graphql-java:$graphqlJavaVersion"
 
     testImplementation("org.assertj:assertj-core:$assertJVersion")

spring-graphql-webmvc/build.gradle

@@ -7,6 +7,7 @@ dependencies {
     implementation "org.springframework:spring-context:$springVersion"
     implementation "com.fasterxml.jackson.core:jackson-databind:$jacksonVersion"
     api "com.graphql-java:graphql-java:$graphqlJavaVersion"
+    implementation project(':spring-graphql-common')
     implementation group: 'javax.servlet', name: 'javax.servlet-api', version: '4.0.1'
 
     testImplementation("org.assertj:assertj-core:$assertJVersion")

spring-graphql-webmvc/src/main/java/org/springframework/graphql/servlet/GraphQLInvocationData.java

@@ -1,31 +0,0 @@
-package org.springframework.graphql.servlet;
-
-import graphql.Assert;
-
-import java.util.Collections;
-import java.util.Map;
-
-public class GraphQLInvocationData {
-
-    private final String query;
-    private final String operationName;
-    private final Map<String, Object> variables;
-
-    public GraphQLInvocationData(String query, String operationName, Map<String, Object> variables) {
-        this.query = Assert.assertNotNull(query, () -> "query must be provided");
-        this.operationName = operationName;
-        this.variables = variables != null ? variables : Collections.emptyMap();
-    }
-
-    public String getQuery() {
-        return query;
-    }
-
-    public String getOperationName() {
-        return operationName;
-    }
-
-    public Map<String, Object> getVariables() {
-        return variables;
-    }
-}

spring-graphql-webmvc/src/main/java/org/springframework/graphql/servlet/components/GraphQLController.java

@@ -1,18 +1,27 @@
 package org.springframework.graphql.servlet.components;
 
 
+import graphql.GraphQL;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.graphql.servlet.GraphQLInvocationData;
+import org.springframework.graphql.DefaultGraphQLInterceptor;
+import org.springframework.graphql.GraphQLHandler;
+import org.springframework.graphql.GraphQLInterceptor;
+import org.springframework.graphql.GraphQLRequestBody;
 import org.springframework.http.MediaType;
 import org.springframework.web.servlet.function.RequestPredicates;
 import org.springframework.web.servlet.function.RouterFunction;
 import org.springframework.web.servlet.function.ServerRequest;
 import org.springframework.web.servlet.function.ServerResponse;
+import reactor.core.publisher.Mono;
 
+import javax.annotation.PostConstruct;
 import javax.servlet.ServletException;
 import java.io.IOException;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
 
 import static org.springframework.web.servlet.function.RouterFunctions.route;
 
@@ -20,7 +29,20 @@ import static org.springframework.web.servlet.function.RouterFunctions.route;
 public class GraphQLController {
 
     @Autowired
-    GraphQLRequestHandler graphQLRequestHandler;
+    GraphQL graphQL;
+
+    GraphQLHandler graphQLHandler;
+
+    @Autowired(required = false)
+    GraphQLInterceptor graphQLInterceptor;
+
+
+    @PostConstruct
+    public void init() {
+        GraphQLInterceptor interceptor = graphQLInterceptor == null ? new DefaultGraphQLInterceptor() : graphQLInterceptor;
+        this.graphQLHandler = new GraphQLHandler(graphQL, interceptor);
+    }
+
 
     @Bean
     public RouterFunction<ServerResponse> routerFunction() {
@@ -33,9 +55,9 @@ public class GraphQLController {
     }
 
     private ServerResponse graphqlPOST(ServerRequest serverRequest) {
-        GraphQLRequestBody body = null;
+        GraphQLServletRequestBody body = null;
         try {
-            body = serverRequest.body(GraphQLRequestBody.class);
+            body = serverRequest.body(GraphQLServletRequestBody.class);
         } catch (ServletException | IOException e) {
             e.printStackTrace();
         }
@@ -43,9 +65,29 @@ public class GraphQLController {
         if (query == null) {
             query = "";
         }
-        GraphQLInvocationData invocationData = new GraphQLInvocationData(query, body.getOperationName(), body.getVariables());
-        Object resultBody = graphQLRequestHandler.invoke(invocationData, serverRequest.headers());
-        return ServerResponse.ok().body(resultBody);
+        Map<String, Object> variables = body.getVariables();
+        if (variables == null) {
+            variables = Collections.emptyMap();
+        }
+
+        GraphQLRequestBody graphQLRequestBody = new GraphQLRequestBody(query, body.getOperationName(), variables);
+
+        Mono<Map<String, Object>> responseRawMono = graphQLHandler.graphqlPOST(graphQLRequestBody, serverRequest.headers().asHttpHeaders())
+                .map(graphQLResponseBody -> {
+                    //TODO: this should be handled better:
+                    // we don't want to serialize `null` values for `errors` and `extensions`
+                    // this is why we convert it to a Map here
+                    Map<String, Object> responseBodyRaw = new LinkedHashMap<>();
+                    responseBodyRaw.put("data", graphQLResponseBody.getData());
+                    if (graphQLResponseBody.getErrors() != null) {
+                        responseBodyRaw.put("errors", graphQLResponseBody.getErrors());
+                    }
+                    if (graphQLResponseBody.getExtensions() != null) {
+                        responseBodyRaw.put("extensions", graphQLResponseBody.getExtensions());
+                    }
+                    return responseBodyRaw;
+                });
+        return ServerResponse.ok().body(responseRawMono);
     }
 
 }

spring-graphql-webmvc/src/main/java/org/springframework/graphql/servlet/components/GraphQLRequestHandler.java

@@ -1,55 +0,0 @@
-package org.springframework.graphql.servlet.components;
-
-import graphql.ExecutionInput;
-import graphql.ExecutionResult;
-import graphql.GraphQL;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.graphql.servlet.GraphQLInvocationData;
-import org.springframework.stereotype.Component;
-import org.springframework.util.Assert;
-import org.springframework.web.servlet.function.ServerRequest;
-
-import java.util.Map;
-import java.util.concurrent.CompletableFuture;
-
-@Component
-public class GraphQLRequestHandler {
-
-    @Autowired
-    private GraphQL graphQL;
-
-
-    public Object invoke(GraphQLInvocationData invocationData,
-                         ServerRequest.Headers headers) {
-        Assert.notNull(graphQL, "graphQL is not set");
-        ExecutionInput executionInput = ExecutionInput.newExecutionInput()
-                .query(invocationData.getQuery())
-                .operationName(invocationData.getOperationName())
-                .variables(invocationData.getVariables())
-                .build();
-        customizeExecutionInput(executionInput, headers);
-        CompletableFuture<ExecutionInput> customizedExecutionInput = customizeExecutionInput(executionInput, headers);
-        CompletableFuture<ExecutionResult> executionResultCompletableFuture = customizedExecutionInput.thenCompose(graphQL::executeAsync);
-        return handleExecutionResult(executionResultCompletableFuture);
-    }
-
-    protected CompletableFuture<ExecutionInput> customizeExecutionInput(ExecutionInput executionInput,
-                                                                        ServerRequest.Headers headers) {
-        return CompletableFuture.completedFuture(executionInput);
-    }
-
-    protected Object handleExecutionResult(CompletableFuture<ExecutionResult> executionResultCF) {
-        if (executionResultCF.isDone()) {
-            return toSpecification(executionResultCF);
-        }
-        return executionResultCF.thenApply(ExecutionResult::toSpecification);
-    }
-
-    private Map<String, Object> toSpecification(CompletableFuture<ExecutionResult> executionResultCF) {
-        try {
-            return executionResultCF.get().toSpecification();
-        } catch (Exception e) {
-            throw new RuntimeException("Should not happen", e);
-        }
-    }
-}

spring-graphql-webmvc/src/main/java/org/springframework/graphql/servlet/components/GraphQLServletRequestBody.java

@@ -2,7 +2,7 @@ package org.springframework.graphql.servlet.components;
 
 import java.util.Map;
 
-public class GraphQLRequestBody {
+public class GraphQLServletRequestBody {
     private String query;
     private String operationName;
     private Map<String, Object> variables;