I have got a error when runing like this
BuildContext buildContext= DefaultBuildContext.reflectionContext; GraphQLOutputType a=buildContext.getOutputType(Map.class);

and the error result is

7:55.723 [main] WARN graphql.java.generator.type.TypeGenerator - Failed to generate type named sun_reflect_generics_reflectiveObjects_TypeVariableImpl with kind INPUT_OBJECT 14:47:55.728 [main] DEBUG graphql.java.generator.type.TypeGenerator - Failed to generate type, exception is graphql.AssertException: wrappedType can't be null at graphql.Assert.assertNotNull(Assert.java:10) at graphql.schema.GraphQLList.<init>(GraphQLList.java:13)