added ToMany.removeById()

Author: greenrobot

objectbox-java/src/main/java/io/objectbox/relation/ToMany.java

@@ -327,6 +327,26 @@ public synchronized boolean remove(Object object) {
         return removed;
     }
 
+    @Beta
+    /** Removes an object by its entity ID. */
+    public synchronized TARGET removeById(long id) {
+        ensureEntities();
+        int size = entities.size();
+        IdGetter<TARGET> idGetter = relationInfo.targetInfo.getIdGetter();
+        for (int i = 0; i < size; i++) {
+            TARGET candidate = entities.get(i);
+            if (idGetter.getId(candidate) == id) {
+                TARGET removed = remove(i);
+                if (removed != candidate) {
+                    throw new IllegalStateException("Mismatch: " + removed + " vs. " + candidate);
+                }
+                return candidate;
+            }
+
+        }
+        return null;
+    }
+
     @Override
     public synchronized boolean removeAll(Collection<?> objects) {
         boolean changes = false;
@@ -518,7 +538,7 @@ public boolean hasA(QueryFilter<TARGET> filter) {
     public boolean hasAll(QueryFilter<TARGET> filter) {
         ensureEntities();
         Object[] objects = entities.toArray();
-        if(objects.length == 0) {
+        if (objects.length == 0) {
             return false;
         }
         for (Object target : objects) {

tests/objectbox-java-test/src/main/java/io/objectbox/relation/ToManyTest.java

@@ -187,6 +187,20 @@ public void testRemoveAll() {
         assertOrder2And4Removed(count, customer, toMany);
     }
 
+    @Test
+    public void testRemoveById() {
+        int count = 5;
+        Customer customer = putCustomerWithOrders(count);
+        ToMany<Order> toMany = (ToMany<Order>) customer.orders;
+        Order removed1 = toMany.removeById(toMany.get(3).getId());
+        assertEquals("order4", removed1.getText());
+        Order removed2 = toMany.removeById(toMany.get(1).getId());
+        assertEquals("order2", removed2.getText());
+        assertNull(toMany.removeById(42));
+        customerBox.put(customer);
+        assertOrder2And4Removed(count, customer, toMany);
+    }
+
     @Test
     public void testRetainAll() {
         int count = 5;