src/main/java/net/hostsharing/hsadminng/hs/booking/item/HsBookingItemEntity.java

@@ -11,6 +11,7 @@ import lombok.NoArgsConstructor;
 import lombok.Setter;
 import net.hostsharing.hsadminng.hs.office.debitor.HsOfficeDebitorEntity;
 import net.hostsharing.hsadminng.hs.office.relation.HsOfficeRelationEntity;
+import net.hostsharing.hsadminng.mapper.PatchableMapWrapper;
 import net.hostsharing.hsadminng.rbac.rbacdef.RbacView;
 import net.hostsharing.hsadminng.rbac.rbacdef.RbacView.SQL;
 import net.hostsharing.hsadminng.rbac.rbacobject.RbacObject;
@@ -25,15 +26,16 @@ import jakarta.persistence.Id;
 import jakarta.persistence.JoinColumn;
 import jakarta.persistence.ManyToOne;
 import jakarta.persistence.Table;
+import jakarta.persistence.Transient;
 import jakarta.persistence.Version;
 import java.io.IOException;
 import java.time.LocalDate;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.UUID;
 
 import static java.util.Optional.ofNullable;
-import static net.hostsharing.hsadminng.mapper.PatchableMap.mapToString;
 import static net.hostsharing.hsadminng.mapper.PostgresDateRange.lowerInclusiveFromPostgresDateRange;
 import static net.hostsharing.hsadminng.mapper.PostgresDateRange.toPostgresDateRange;
 import static net.hostsharing.hsadminng.mapper.PostgresDateRange.upperInclusiveFromPostgresDateRange;
@@ -65,7 +67,7 @@ public class HsBookingItemEntity implements Stringifyable, RbacObject {
             .withProp(e -> e.getDebitor().toShortString())
             .withProp(e -> e.getValidity().asString())
             .withProp(HsBookingItemEntity::getCaption)
-            .withProp(e -> mapToString(e.getResources()))
+            .withProp(HsBookingItemEntity::getResources)
             .quotedValues(false);
 
     @Id
@@ -91,7 +93,10 @@ public class HsBookingItemEntity implements Stringifyable, RbacObject {
     @Setter(AccessLevel.NONE)
     @Type(JsonType.class)
     @Column(columnDefinition = "resources")
-    private Map<String, Object> resources = new TreeMap<>();
+    private Map<String, Object> resources = new HashMap<>();
+
+    @Transient
+    private PatchableMapWrapper resourcesWrapper;
 
     public void setValidFrom(final LocalDate validFrom) {
         setValidity(toPostgresDateRange(validFrom, getValidTo()));
@@ -109,6 +114,17 @@ public class HsBookingItemEntity implements Stringifyable, RbacObject {
         return upperInclusiveFromPostgresDateRange(getValidity());
     }
 
+    public PatchableMapWrapper getResources() {
+        if ( resourcesWrapper == null ) {
+            resourcesWrapper = new PatchableMapWrapper(resources);
+        }
+        return resourcesWrapper;
+    }
+
+    public void putResources(Map<String, Object> entries) {
+        resourcesWrapper.assign(entries);
+    }
+
     @Override
     public String toString() {
         return stringify.apply(this);

src/main/java/net/hostsharing/hsadminng/hs/booking/item/HsBookingItemEntityPatcher.java

@@ -25,19 +25,13 @@ public class HsBookingItemEntityPatcher implements EntityPatcher<HsBookingItemPa
         OptionalFromJson.of(resource.getCaption())
                 .ifPresent(entity::setCaption);
         Optional.ofNullable(resource.getResources())
-                .ifPresent(r -> setResources(entity, r));
+                .ifPresent(r -> entity.putResources(objectToMap(resource.getResources())));
         OptionalFromJson.of(resource.getValidFrom())
                 .ifPresent(entity::setValidFrom);
         OptionalFromJson.of(resource.getValidTo())
                 .ifPresent(entity::setValidTo);
     }
 
-    private static void setResources(
-            final HsBookingItemEntity entity,
-            final ArbitraryBookingResourcesJsonResource arbitraryBookingResourcesJsonResource) {
-        entity.getResources().putAll(objectToMap(arbitraryBookingResourcesJsonResource));
-    }
-
     static Map<String, Object> objectToMap(final Object obj) {
         return stream(obj.getClass().getDeclaredFields())
                 .map(field -> {

src/main/java/net/hostsharing/hsadminng/mapper/PatchMap.java

@@ -0,0 +1,30 @@
+package net.hostsharing.hsadminng.mapper;
+
+import org.apache.commons.lang3.tuple.ImmutablePair;
+
+import jakarta.validation.constraints.NotNull;
+import java.util.Map;
+import java.util.TreeMap;
+
+import static java.util.Arrays.stream;
+
+/**
+ * This is a map which can take key-value-pairs where the value can be null
+ * thus JSON nullable object structures from HTTP PATCH can be represented.
+ */
+public class PatchMap extends TreeMap<String, Object> {
+
+    public PatchMap(final ImmutablePair<String, Object>[] entries) {
+        stream(entries).forEach(r -> put(r.getKey(), r.getValue()));
+    }
+
+//    @SafeVarargs
+//    public static Map<String, Object> patchMap(final ImmutablePair<String, Object>... entries) {
+//        return new PatchMap(entries);
+//    }
+//
+//    @NotNull
+//    public static ImmutablePair<String, Object> entry(final String key, final Object value) {
+//        return new ImmutablePair<>(key, value);
+//    }
+}

src/main/java/net/hostsharing/hsadminng/mapper/PatchableMap.java

@@ -1,42 +0,0 @@
-package net.hostsharing.hsadminng.mapper;
-
-import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemEntity;
-import org.apache.commons.lang3.tuple.ImmutablePair;
-
-import jakarta.validation.constraints.NotNull;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.function.BiConsumer;
-
-import static java.util.stream.Collectors.joining;
-
-public class PatchableMap {
-
-    @SafeVarargs
-    public static Map<String, Object> patchableMap(final ImmutablePair<String, Object>... entries) {
-        final var map = new HashMap<String, Object>();
-        Arrays.stream(entries).forEach(r -> map.put(r.getKey(), r.getValue()));
-        return map;
-    }
-
-    @NotNull
-    public static ImmutablePair<String, Object> entry(final String key, final Object value) {
-        return new ImmutablePair<>(key, value);
-    }
-
-    public static BiConsumer<? extends Object, ? super Map<String, Object>> assignMap = (HsBookingItemEntity i, Map<String, Object> r) -> {
-        i.getResources().clear();
-        i.getResources().putAll(r);
-    };
-
-    public static String mapToString(final Map<String, Object> resources) {
-        return "{ "
-                + (
-                resources.keySet().stream().sorted()
-                        .map(k -> k + ": " + resources.get(k)))
-                .collect(joining(", ")
-                )
-                + " }";
-    }
-}

src/main/java/net/hostsharing/hsadminng/mapper/PatchableMapWrapper.java

@@ -0,0 +1,107 @@
+package net.hostsharing.hsadminng.mapper;
+
+import org.apache.commons.lang3.tuple.ImmutablePair;
+
+import jakarta.validation.constraints.NotNull;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.joining;
+
+/** This class wraps another (usually persistent) map and
+ * supports applying `PatchMap` as well as a toString method with stable entry order.
+ */
+public class PatchableMapWrapper implements Map<String, Object> {
+
+    private final Map<String, Object> delegate;
+
+    public PatchableMapWrapper(final Map<String, Object> map) {
+        delegate = map;
+    }
+
+    @NotNull
+    public static ImmutablePair<String, Object> entry(final String key, final Object value) {
+        return new ImmutablePair<>(key, value);
+    }
+
+    public void assign(final Map<String, Object> entries) {
+        delegate.clear();
+        delegate.putAll(entries);
+    }
+
+    public String toString() {
+        return "{ "
+                + (
+                    keySet().stream().sorted()
+                            .map(k -> k + ": " + get(k)))
+                            .collect(joining(", ")
+                )
+                + " }";
+    }
+
+    // --- below just delegating methods --------------------------------
+
+    @Override
+    public int size() {
+        return delegate.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return delegate.isEmpty();
+    }
+
+    @Override
+    public boolean containsKey(final Object key) {
+        return delegate.containsKey(key);
+    }
+
+    @Override
+    public boolean containsValue(final Object value) {
+        return delegate.containsValue(value);
+    }
+
+    @Override
+    public Object get(final Object key) {
+        return delegate.get(key);
+    }
+
+    @Override
+    public Object put(final String key, final Object value) {
+        return delegate.put(key, value);
+    }
+
+    @Override
+    public Object remove(final Object key) {
+        return delegate.remove(key);
+    }
+
+    @Override
+    public void putAll(final Map<? extends String, ?> m) {
+        delegate.putAll(m);
+    }
+
+    @Override
+    public void clear() {
+        delegate.clear();
+    }
+
+    @Override
+    public Set<String> keySet() {
+        return delegate.keySet();
+    }
+
+    @Override
+    public Collection<Object> values() {
+        return delegate.values();
+    }
+
+    @Override
+    public Set<Entry<String, Object>> entrySet() {
+        return delegate.entrySet();
+    }
+}

src/test/java/net/hostsharing/hsadminng/hs/booking/item/HsBookingItemControllerAcceptanceTest.java

@@ -233,8 +233,9 @@ class HsBookingItemControllerAcceptanceTest extends ContextBasedTestWithCleanup
                             "validFrom": "2020-06-05",
                             "validTo": "2022-12-31",
                             "resources": {
-                                "CPUs": "2",
+                                "CPUs": "4",
-                                "SSD-storage": "512"
+                                "HDD_storage": null,
+                                "SSD-storage": "4096"
                             }
                         }
                         """)
@@ -249,7 +250,10 @@ class HsBookingItemControllerAcceptanceTest extends ContextBasedTestWithCleanup
                             "caption": "some test-booking",
                             "validFrom": "2020-06-05",
                             "validTo": "2022-12-31",
-                            "resources": null
+                            "resources": {
+                                "CPUs": "2",
+                                "SSD-storage": "2048"
+                            }
                          }
                     """)); // @formatter:on
 
@@ -290,7 +294,9 @@ class HsBookingItemControllerAcceptanceTest extends ContextBasedTestWithCleanup
                             "caption": "some test-booking",
                             "validFrom": "2022-11-01",
                             "validTo": "2022-12-31",
-                            "resources": null
+                            "resources": {
+                                "CPUs": 5
+                            }
                         }
                     """)); // @formatter:on
 

src/test/java/net/hostsharing/hsadminng/hs/booking/item/HsBookingItemEntityPatcherUnitTest.java

@@ -4,7 +4,6 @@ import io.hypersistence.utils.hibernate.type.range.Range;
 import net.hostsharing.hsadminng.hs.booking.generated.api.v1.model.ArbitraryBookingResourcesJsonResource;
 import net.hostsharing.hsadminng.hs.booking.generated.api.v1.model.HsBookingItemPatchResource;
 import net.hostsharing.hsadminng.hs.office.debitor.HsOfficeDebitorEntity;
-import net.hostsharing.hsadminng.mapper.PatchableMap;
 import net.hostsharing.hsadminng.rbac.test.PatchUnitTestBase;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.TestInstance;
@@ -92,7 +91,7 @@ class HsBookingItemEntityPatcherUnitTest extends PatchUnitTestBase<
                         "resources",
                         HsBookingItemPatchResource::setResources,
                         PATCHED_RESOURCES,
-                        PatchableMap.assignMap,
+                        HsBookingItemEntity::putResources,
                         objectToMap(PATCHED_RESOURCES))
                         .notNullable(),
                 new JsonNullableProperty<>(

src/test/java/net/hostsharing/hsadminng/hs/booking/item/HsBookingItemRepositoryIntegrationTest.java

@@ -22,9 +22,9 @@ import jakarta.servlet.http.HttpServletRequest;
 import java.time.LocalDate;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 
-import static net.hostsharing.hsadminng.mapper.PatchableMap.entry;
+import static java.util.Map.entry;
-import static net.hostsharing.hsadminng.mapper.PatchableMap.patchableMap;
 import static net.hostsharing.hsadminng.rbac.rbacgrant.RawRbacGrantEntity.distinctGrantDisplaysOf;
 import static net.hostsharing.hsadminng.rbac.rbacrole.RawRbacRoleEntity.distinctRoleNamesOf;
 import static net.hostsharing.hsadminng.rbac.test.Array.fromFormatted;
@@ -312,7 +312,7 @@ class HsBookingItemRepositoryIntegrationTest extends ContextBasedTestWithCleanup
                     .caption("some temp booking item")
                     .validity(Range.closedOpen(
                             LocalDate.parse("2020-01-01"), LocalDate.parse("2023-01-01")))
-                    .resources(patchableMap(
+                    .resources(Map.ofEntries(
                             entry("CPUs", 1),
                             entry("SSD-storage", 256)))
                     .build();