Merge pull request #4 from sergehuber/quick-fixes

Servlet API downgrade, correction in groupId and made some service references optional

Author: yrashk

build.gradle

@@ -65,7 +65,7 @@ publishing {
     publications {
         MyPublication(MavenPublication) {
             from components.java
-            groupId 'graphql-java-servlet'
+            groupId 'com.graphql-java'
             artifactId project.name
             version project.version
 
@@ -112,7 +112,7 @@ dependencies {
     compile 'biz.aQute.bnd:biz.aQute.bndlib:3.1.0'
 
     // Servlet
-    compile 'javax.servlet:javax.servlet-api:3.1.0'
+    compile 'javax.servlet:javax.servlet-api:3.0.1'
     // Multipart support
     compile 'commons-fileupload:commons-fileupload:1.3.1'
 

src/main/java/graphql/servlet/GraphQLServlet.java

@@ -131,15 +131,15 @@ public String[] getMutations() {
     private GraphQLContextBuilder contextBuilder = new DefaultGraphQLContextBuilder();
     private ExecutionStrategyProvider executionStrategyProvider = new EnhancedExecutionStrategyProvider();
 
-    @Reference
+    @Reference(cardinality = ReferenceCardinality.OPTIONAL)
     public void setContextProvider(GraphQLContextBuilder contextBuilder) {
         this.contextBuilder = contextBuilder;
     }
     public void unsetContextProvider(GraphQLContextBuilder contextBuilder) {
         this.contextBuilder = new DefaultGraphQLContextBuilder();
     }
 
-    @Reference
+    @Reference(cardinality = ReferenceCardinality.OPTIONAL)
     public void setExecutionStrategyProvider(ExecutionStrategyProvider provider) {
         executionStrategyProvider = provider;
     }