Provide ability to plug in pre configured objectmapper

src/main/java/graphql/servlet/ConfiguringObjectMapperProvider.java

@@ -1,32 +1,34 @@
 package graphql.servlet;
 
-import com.fasterxml.jackson.databind.InjectableValues;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
 
 public class ConfiguringObjectMapperProvider implements ObjectMapperProvider {
 
+  private final ObjectMapper objectMapperTemplate;
+
   private final ObjectMapperConfigurer objectMapperConfigurer;
 
+  public ConfiguringObjectMapperProvider(ObjectMapper objectMapperTemplate, ObjectMapperConfigurer objectMapperConfigurer) {
+    this.objectMapperTemplate = objectMapperTemplate == null ? new ObjectMapper() : objectMapperTemplate;
+    this.objectMapperConfigurer = objectMapperConfigurer == null ? new DefaultObjectMapperConfigurer() : objectMapperConfigurer;
+  }
+
+  public ConfiguringObjectMapperProvider(ObjectMapper objectMapperTemplate) {
+      this(objectMapperTemplate, null);
+  }
+
   public ConfiguringObjectMapperProvider(ObjectMapperConfigurer objectMapperConfigurer) {
-    this.objectMapperConfigurer = objectMapperConfigurer;
+    this(null, objectMapperConfigurer);
   }
 
   public ConfiguringObjectMapperProvider() {
-    this.objectMapperConfigurer = new DefaultObjectMapperConfigurer();
+    this(null, null);
   }
 
   @Override
   public ObjectMapper provide() {
-    ObjectMapper mapper = new ObjectMapper().disable(
-      SerializationFeature.FAIL_ON_EMPTY_BEANS).registerModule(new Jdk8Module());
-    objectMapperConfigurer.configure(mapper);
-
-    InjectableValues.Std injectableValues = new InjectableValues.Std();
-    injectableValues.addValue(ObjectMapper.class, mapper);
-    mapper.setInjectableValues(injectableValues);
-
+    ObjectMapper mapper = this.objectMapperTemplate.copy();
+    this.objectMapperConfigurer.configure(mapper);
     return mapper;
   }
 }

src/main/java/graphql/servlet/DefaultObjectMapperConfigurer.java

@@ -1,13 +1,20 @@
 package graphql.servlet;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
 
 /**
  * @author Andrew Potter
  */
 public class DefaultObjectMapperConfigurer implements ObjectMapperConfigurer {
+
     @Override
     public void configure(ObjectMapper mapper) {
-
+        // default configuration for GraphQL Java Servlet
+        mapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
+        mapper.registerModule(new Jdk8Module());
+        mapper.setDefaultPropertyInclusion(JsonInclude.Include.ALWAYS);
     }
 }

src/main/java/graphql/servlet/GraphQLObjectMapper.java

@@ -1,6 +1,5 @@
 package graphql.servlet;
 
-import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.MappingIterator;
@@ -45,8 +44,7 @@ public ObjectMapper getJacksonMapper() {
             synchronized(this) {
                 result = mapper;
                 if (result == null) { // Second check (with locking)
-                    mapper = result = objectMapperProvider.provide().copy();
-                    mapper.setDefaultPropertyInclusion(JsonInclude.Include.ALWAYS);
+                    mapper = result = objectMapperProvider.provide();
                 }
             }
         }

src/main/java/graphql/servlet/internal/VariablesDeserializer.java

@@ -1,10 +1,10 @@
 package graphql.servlet.internal;
 
 import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.ObjectCodec;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.JsonDeserializer;
-import com.fasterxml.jackson.databind.ObjectMapper;
 
 import java.io.IOException;
 import java.util.Map;
@@ -15,17 +15,17 @@
 public class VariablesDeserializer extends JsonDeserializer<Map<String, Object>> {
     @Override
     public Map<String, Object> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
-        return deserializeVariablesObject(p.readValueAs(Object.class), (ObjectMapper) ctxt.findInjectableValue(ObjectMapper.class.getName(), null, null));
+        return deserializeVariablesObject(p.readValueAs(Object.class), p.getCodec());
     }
 
-    public static Map<String, Object> deserializeVariablesObject(Object variables, ObjectMapper mapper) {
+    public static Map<String, Object> deserializeVariablesObject(Object variables, ObjectCodec codec) {
         if (variables instanceof Map) {
             @SuppressWarnings("unchecked")
             Map<String, Object> genericVariables = (Map<String, Object>) variables;
             return genericVariables;
         } else if (variables instanceof String) {
             try {
-                return mapper.readValue((String) variables, new TypeReference<Map<String, Object>>() {});
+                return codec.readValue(codec.getFactory().createParser((String) variables), new TypeReference<Map<String, Object>>() {});
             } catch (IOException e) {
                 throw new RuntimeException(e);
             }