Feature/default utf8 encoding

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

@@ -87,9 +87,10 @@ private GraphQLInvocationInput getGraphQLInvocationInput(
                   }
                 });
 
-    String query = read(inputStream);
+    String query = read(inputStream, request.getCharacterEncoding());
     if ("query".equals(key) && isSingleQuery(query)) {
-      GraphQLRequest graphqlRequest = buildRequestFromQuery(query, graphQLObjectMapper, parts);
+      GraphQLRequest graphqlRequest =
+          buildRequestFromQuery(query, graphQLObjectMapper, parts, request.getCharacterEncoding());
       variablesMap.ifPresent(m -> mapMultipartVariables(graphqlRequest, m, parts));
       return invocationInputFactory.create(graphqlRequest, request, response);
     } else if (isSingleQuery(query)) {
@@ -109,6 +110,7 @@ private Optional<Part> findPart(Map<String, List<Part>> parts) {
         .filter(parts::containsKey)
         .map(key -> getPart(parts, key))
         .findFirst()
+        .filter(Optional::isPresent)
         .map(Optional::get);
   }
 
@@ -141,33 +143,38 @@ private void mapMultipartVariables(
   }
 
   private GraphQLRequest buildRequestFromQuery(
-      String query, GraphQLObjectMapper graphQLObjectMapper, Map<String, List<Part>> parts)
+      String query,
+      GraphQLObjectMapper graphQLObjectMapper,
+      Map<String, List<Part>> parts,
+      String charset)
       throws IOException {
     Map<String, Object> variables = null;
     final Optional<Part> variablesItem = getPart(parts, "variables");
     if (variablesItem.isPresent()) {
       variables =
-          graphQLObjectMapper.deserializeVariables(read(variablesItem.get().getInputStream()));
+          graphQLObjectMapper.deserializeVariables(
+              read(variablesItem.get().getInputStream(), charset));
     }
 
     Map<String, Object> extensions = null;
     final Optional<Part> extensionsItem = getPart(parts, "extensions");
     if (extensionsItem.isPresent()) {
       extensions =
-          graphQLObjectMapper.deserializeExtensions(read(extensionsItem.get().getInputStream()));
+          graphQLObjectMapper.deserializeExtensions(
+              read(extensionsItem.get().getInputStream(), charset));
     }
 
     String operationName = null;
     final Optional<Part> operationNameItem = getPart(parts, "operationName");
     if (operationNameItem.isPresent()) {
-      operationName = read(operationNameItem.get().getInputStream()).trim();
+      operationName = read(operationNameItem.get().getInputStream(), charset).trim();
     }
 
     return new GraphQLRequest(query, variables, extensions, operationName);
   }
 
-  private String read(InputStream inputStream) throws IOException {
-    try (InputStreamReader streamReader = new InputStreamReader(inputStream);
+  private String read(InputStream inputStream, String charset) throws IOException {
+    try (InputStreamReader streamReader = new InputStreamReader(inputStream, charset);
         BufferedReader reader = new BufferedReader(streamReader)) {
       return reader.lines().collect(joining());
     }

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

@@ -10,7 +10,6 @@
 import graphql.kickstart.servlet.input.GraphQLInvocationInputFactory;
 import java.io.IOException;
 import java.util.List;
-import java.util.stream.Collectors;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 

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

@@ -4,6 +4,7 @@
 import graphql.GraphQLException;
 import graphql.kickstart.execution.input.GraphQLInvocationInput;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import lombok.extern.slf4j.Slf4j;
@@ -32,14 +33,17 @@ public HttpRequestHandlerImpl(
   @Override
   public void handle(HttpServletRequest request, HttpServletResponse response) throws IOException {
     try {
+      if (request.getCharacterEncoding() == null) {
+        request.setCharacterEncoding(StandardCharsets.UTF_8.name());
+      }
       GraphQLInvocationInputParser invocationInputParser =
           GraphQLInvocationInputParser.create(
               request,
               configuration.getInvocationInputFactory(),
               configuration.getObjectMapper(),
               configuration.getContextSetting());
       GraphQLInvocationInput invocationInput =
-          invocationInputParser.getGraphQLInvocationInput(request, response);
+          invocationInputParser.  getGraphQLInvocationInput(request, response);
       requestInvoker.execute(invocationInput, request, response);
     } catch (GraphQLException | JsonProcessingException e) {
       response.setStatus(STATUS_BAD_REQUEST);