Allowed classes to have no attributes (#138)

Allowed superclasses to have no attributes

An error message was thrown if a class had no immediate or superclass
attributes to be saved to the database. This is a valid check on a low
level class, but it's entirely fair to have a superclass (typically
abstract) which has no attributes, and this error was being thrown here
too.

The check is safe to remove as it's illegal to save a class with no
attributes to the database because there will be no @id field so will
throw an exception anyway.

Co-authored-by: Tim Faulkes <[email protected]>

Author: tim-aero

src/main/java/com/aerospike/mapper/tools/ClassCacheEntry.java

@@ -146,10 +146,6 @@ public ClassCacheEntry<T> construct() {
         this.loadPropertiesFromClass();
         this.superClazz = ClassCache.getInstance().loadClass(this.clazz.getSuperclass(), this.mapper, !this.mapAll);
         this.binCount = this.values.size() + (superClazz != null ? superClazz.binCount : 0);
-        if (this.binCount == 0) {
-            throw new AerospikeException(String.format("Class %s has no values defined to be stored in the database",
-                    clazz.getSimpleName()));
-        }
         this.formOrdinalsFromValues();
         Method factoryConstructorMethod = findConstructorFactoryMethod();
         if (factoryConstructorMethod == null) {

src/test/java/com/aerospike/mapper/BaseClassWithNoAttributesTest.java

@@ -0,0 +1,129 @@
+package com.aerospike.mapper;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import com.aerospike.mapper.annotations.AerospikeBin;
+import com.aerospike.mapper.annotations.AerospikeEmbed;
+import com.aerospike.mapper.annotations.AerospikeEmbed.EmbedType;
+import com.aerospike.mapper.annotations.AerospikeKey;
+import com.aerospike.mapper.annotations.AerospikeRecord;
+import com.aerospike.mapper.tools.AeroMapper;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+public class BaseClassWithNoAttributesTest extends AeroMapperBaseTest {
+	
+	public static class Animal {
+	}
+	
+	@Data
+	@AllArgsConstructor
+	@AerospikeRecord(namespace = "test", set = "zoo")
+	public static class Dog extends Animal{
+		
+		@AerospikeKey
+		private String dogId;
+	    private String breed;
+	    
+	    public Dog(){
+			dogId = "" + ((int) (Math.random() * 1000));
+	    }
+	    
+	    public Dog(String breed) {
+	    	this.breed = breed;
+			dogId = "" + ((int) (Math.random() * 1000));
+	    }
+	    
+	    public String getBreed() {
+			return breed;
+		}
+	    
+	    public String getDogId() {
+			return dogId;
+		}
+	}
+	
+	@Data
+	@AllArgsConstructor
+	@AerospikeRecord(namespace = "test", set = "zoo")
+	public static class Cat extends Animal {
+		
+		@AerospikeKey
+		private String catId;
+		private String breed;
+		private String lifeSpan;
+
+		public Cat(String breed, String lifeSpan) {
+			this.breed = breed;
+			this.lifeSpan = lifeSpan;
+			
+			catId = "" + ((int) (Math.random() * 1000));
+		}
+
+		public Cat() {
+			catId = "" + ((int) (Math.random() * 1000));
+		}
+		
+		public String getBreed() {
+			return breed;
+		}
+		
+		public String getCatId() {
+			return catId;
+		}
+		
+		public String getLifeSpan() {
+			return lifeSpan;
+		}
+	}
+
+	@AerospikeRecord(namespace = "test", set = "zoo", mapAll = false)
+	@NoArgsConstructor
+	@Data
+	public static class Zoo {
+
+		@AerospikeBin
+		@AerospikeKey
+		private String zooId;
+
+		@AerospikeBin
+		@AerospikeEmbed(type = EmbedType.LIST, elementType = EmbedType.MAP)
+		private List<Animal> animalsList;
+
+		public Zoo(String zooId, List<Animal> animalsList) {
+			super();
+			this.zooId = zooId;
+			this.animalsList = animalsList;
+		}
+	}
+	
+	
+	@Test
+	public void runTest() {
+		AeroMapper mapper = new AeroMapper.Builder(client).build();
+		
+		Zoo zoo = new Zoo();
+		zoo.setZooId("103");
+		
+		List<Animal> listOfAnimals = new ArrayList<>();
+		listOfAnimals.add(new Cat("Persian", "30"));
+		listOfAnimals.add(new Cat("Indian", "21"));
+		listOfAnimals.add(new Dog("Lab"));
+		listOfAnimals.add(new Cat("Korean", "15"));
+		listOfAnimals.add(new Dog("Desi"));
+		
+		zoo.setAnimalsList(listOfAnimals);
+		mapper.save(zoo);
+
+		Zoo readZoo = mapper.read(Zoo.class, "103");
+		assertEquals(zoo.zooId, readZoo.zooId);
+		assertEquals(zoo, readZoo);
+	}
+}