Allow configuration of websocket by passing configuration fix #157

Author: oliemansm

graphql-java-servlet/src/main/java/graphql/kickstart/servlet/GraphQLConfiguration.java

@@ -120,7 +120,7 @@ public static class Builder {
     private Executor asyncExecutor = Executors.newCachedThreadPool(new GraphQLThreadFactory());
     private long subscriptionTimeout = 0;
     private ContextSetting contextSetting = ContextSetting.PER_QUERY_WITH_INSTRUMENTATION;
-    private Supplier<BatchInputPreProcessor> batchInputPreProcessorSupplier = () -> new NoOpBatchInputPreProcessor();
+    private Supplier<BatchInputPreProcessor> batchInputPreProcessorSupplier = NoOpBatchInputPreProcessor::new;
 
     private Builder(GraphQLInvocationInputFactory.Builder invocationInputFactoryBuilder) {
       this.invocationInputFactoryBuilder = invocationInputFactoryBuilder;

graphql-java-servlet/src/main/java/graphql/kickstart/servlet/GraphQLWebsocketServlet.java

@@ -1,5 +1,6 @@
 package graphql.kickstart.servlet;
 
+import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 import static java.util.stream.Collectors.toList;
 
@@ -20,6 +21,7 @@
 import java.io.EOFException;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -192,8 +194,9 @@ public void modifyHandshake(ServerEndpointConfig sec, HandshakeRequest request,
       response.getHeaders().put(HandshakeResponse.SEC_WEBSOCKET_ACCEPT, allSubscriptionProtocols);
     }
     if (!protocol.isEmpty()) {
+      //noinspection ArraysAsListWithZeroOrOneArgument
       response.getHeaders().put(HandshakeRequest.SEC_WEBSOCKET_PROTOCOL,
-          singletonList(subscriptionProtocolFactory.getProtocol()));
+          new ArrayList<>(asList(subscriptionProtocolFactory.getProtocol())));
     }
   }