From 22e62f93372a53377b7f9c4b6ecf5bc5268feeba Mon Sep 17 00:00:00 2001
From: "angelo.andreussi" <angelo.andreussi@eurotech.com>
Date: Tue, 29 Oct 2024 16:29:45 +0100
Subject: [PATCH] fix: restored possibility to update XMl configurations
 properties with null or empty values

---
 .../xml/adapters/XmlPropertiesAdapter.java    | 15 ++++++----
 .../adapters/XmlPropertiesAdapterTest.java    | 29 +++++++++++++++++++
 2 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/service/api/src/main/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapter.java b/service/api/src/main/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapter.java
index 4b2a8d52765..eb6ab54f302 100644
--- a/service/api/src/main/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapter.java
+++ b/service/api/src/main/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapter.java
@@ -22,6 +22,7 @@
 import java.util.Optional;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
+import java.util.HashMap;
 
 public class XmlPropertiesAdapter<T extends Enum<T>, V extends XmlPropertyAdapted<T>> extends XmlAdapter<V[], Map<String, Object>> {
     private final Class<V> propertyClass;
@@ -47,16 +48,18 @@ public Map<String, Object> unmarshal(V[] properties) {
                     }
                 })
                 .filter(adaptedProp -> xmlPropertyAdapters.containsKey((adaptedProp.getType())))
-                .collect(Collectors.toMap(
-                        XmlPropertyAdapted::getName,
-                        adaptedProp -> {
-                            final XmlPropertyAdapter xmlPropertyAdapter = xmlPropertyAdapters.get(adaptedProp.getType());
-                            return xmlPropertyAdapter.unmarshallValues(adaptedProp);
-                        }));
+                .collect(HashMap::new,
+                        (adaptedPropMap, adaptedProp) -> adaptedPropMap.put(adaptedProp.getName(), extractValueFromXmlProperty(adaptedProp)),
+                        HashMap::putAll); // This is a work-around for Collectors.toMap limitation on null values
 
         return unmarshalledProperties;
     }
 
+    private Object extractValueFromXmlProperty(V adaptedProp) {
+        final XmlPropertyAdapter xmlPropertyAdapter = xmlPropertyAdapters.get(adaptedProp.getType());
+        return xmlPropertyAdapter.unmarshallValues(adaptedProp);
+    }
+
     @Override
     public V[] marshal(Map<String, Object> props) {
         final List<V> adaptedProperties = Optional.ofNullable(props)
diff --git a/service/api/src/test/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapterTest.java b/service/api/src/test/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapterTest.java
index a0776ecadf5..31826b8468d 100644
--- a/service/api/src/test/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapterTest.java
+++ b/service/api/src/test/java/org/eclipse/kapua/model/xml/adapters/XmlPropertiesAdapterTest.java
@@ -260,4 +260,33 @@ public void testUnmarshallingMissingType() {
                 new TestPropertyAdapted("anotherValue", null, "42")
         }));
     }
+
+    //Scenario in which, for example, I update a device configuration with some properties set to the default value (null or "") and some to a defined valued
+    @Test
+    public void testUnmarshallingEmptyNullValuesFields() {
+        final StringPropertyAdapter stringAdapter = Mockito.spy(new StringPropertyAdapter());
+        final BooleanPropertyAdapter booleanAdapter = Mockito.spy(new BooleanPropertyAdapter());
+        final LongPropertyAdapter longAdapter = Mockito.spy(new LongPropertyAdapter());
+        final HashMap<TestTypes, XmlPropertyAdapter> adapters = new HashMap<TestTypes, XmlPropertyAdapter>() {
+            {
+                put(TestTypes.First, stringAdapter);
+                put(TestTypes.Second, booleanAdapter);
+                put(TestTypes.Fourth, longAdapter);
+            }
+        };
+        final XmlPropertiesAdapter instance = new TestPropertiesAdapter(adapters);
+        final Map<String, Object> got = instance.unmarshal(new TestPropertyAdapted[]{
+                new TestPropertyAdapted("aString", TestTypes.First, "TheString"),
+                new TestPropertyAdapted("emptyValues", TestTypes.Second, "", ""),
+                new TestPropertyAdapted("emptyValue", TestTypes.Fourth, ""),
+                new TestPropertyAdapted("nullValue", TestTypes.Fourth, (String) null)
+        });
+        Assert.assertNotNull(got);
+        Assert.assertEquals(4, got.keySet().size());
+        Assert.assertNotNull(got.get("aString"));
+        Assert.assertArrayEquals(new Boolean[]{null, null}, (Boolean[]) got.get("emptyValues"));
+        Assert.assertNull(got.get("emptyValue"));
+        Assert.assertNull(got.get("nullValue"));
+    }
+
 }
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