Merge pull request #194 from mkarg/GH-193

GH-193 May adapter input / output be null?

Author: aguibert

api/src/main/java/javax/json/bind/adapter/JsonbAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -71,8 +71,8 @@ public interface JsonbAdapter<Original, Adapted> {
      * After conversion Adapted type will be mapped to JSON the standard way.
      *
      * @param obj
-     *      Object to convert.
-     * @return Converted object which will be serialized to JSON.
+     *      Object to convert or {@code null}.
+     * @return Converted object which will be serialized to JSON or {@code null}.
      * @throws Exception if there is an error during the conversion.
      */
     Adapted adaptToJson(Original obj) throws Exception;
@@ -81,8 +81,8 @@ public interface JsonbAdapter<Original, Adapted> {
      * This method is used on deserialization only. It contains a conversion logic from type Adapted to type Original.
      *
      * @param obj
-     *      Object to convert.
-     * @return Converted object representing pojo to be set into object graph.
+     *      Object to convert or {@code null}.
+     * @return Converted object representing pojo to be set into object graph or {@code null}.
      * @throws Exception if there is an error during the conversion.
      */
     Original adaptFromJson(Adapted obj) throws Exception;

docs/src/docs/user-guide.adoc

@@ -515,6 +515,8 @@ public class CustomerAnnotated {
 public class CustomerAdapter implements JsonbAdapter<Customer, CustomerAnnotated> {
     @Override
     public CustomerAnnotated adaptToJson(Customer c) throws Exception {
+        if (c == null)
+            return null;
         CustomerAnnotated customer = new Customer();
         customer.setId(c.getId());
         customer.setName(c.getName());
@@ -523,6 +525,8 @@ public class CustomerAdapter implements JsonbAdapter<Customer, CustomerAnnotated
 
     @Override
     public Customer adaptFromJson(CustomerAnnotated adapted) throws Exception {
+        if (adapted == null)
+            return null;
         Customer customer = new Customer();
         customer.setId(adapted.getId());
         customer.setName(adapted.getName());