Support interface superclass (#140)

* Allowed the top of the hierarchy to be an interface.

If classes implement an interface instead of extending an abstract
class, the Java Object Mapper should respect any AerospikeRecords
annotations on the interface.

The Object Mapper will look for definitions in the config file, then any
AerospikeRecords on the specific class, then the superclasses and
finally anything in the interface hierarchy. The first one which defines
a namespace will be the definition which is used.

* Changed the interface scanning to not store information which is not
needed.

* Added convenience methods for getting namespace/set/key/RecordKey

* Apply suggestions from code review

Co-authored-by: Eugene R. <reugpro@gmail.com>

* Update InterfaceHierarchyTest.java

Utilised "addAll" to add vararg children to parent, and removed redundant saving of nested children

* Modified reactive interface

* Implemented reactive methods

* Fixed the reactive test

* More reactive changes

---------

Co-authored-by: Eugene R. <reugpro@gmail.com>

Author: tim-aero

README.md

@@ -30,6 +30,7 @@ The documentation for this project can be found on [javadoc.io](https://www.java
     + 9.2. [Subclasses](#Subclasses)
         + 9.2.1. [Data Inheritance](#Data-Inheritance)
         + 9.2.2. [Subclass Inheritance](#Subclass-Inheritance)
+        + 9.2.3 [Using Interfaces](#Using-Interfaces)        
     + 9.3. [Custom Object Converters](#Custom-Object-Converters)
 10. [External Configuration File](#External-Configuration-File)
     + 10.1. [File Structure](#File-Structure)
@@ -1704,6 +1705,14 @@ public List customers;
 
 The former is considered better style in Java and also provides the Java Object Mapper with information about the elements in the list, so it will optimize its workings to know how to store a list of Customers. The latter gives it no type information so it must derive the type -- and hence how to map it to Aerospike -- for every element in this list. This can have a noticeable performance impact for large lists, as well as consuming more database space (as it must store the runtime type of each element in the list in addition to the data).
 
+### Using Interfaces
+Sometimes it is better to have an interface to group common types rather an an abstract superclass. In this case the Object Mapper supports placing the `@AerospikeReocrd` annotation on the interface and it will behave as if the annotation was on a superclass. There are multiple different was of placing the `@AerospikeRecord` annotation on a single class, and the order the Object Mapper looks for them in is:
+1. Configuration file
+2. Class level definition
+3. First parent class with `@AerospikeRecord` annotation (of any ancestor)
+4. Interface with `@AerospikeRecord` annotation (first one found)
+
+Once the Object Mapper finds an appropriate annotation it ignores any further annotations and uses the definitions on the first one found.
 
 ----
 

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

@@ -726,4 +726,28 @@ private Policy getPolicyByClassAndType(Class<?> clazz, PolicyType policyType) {
             throw new UnsupportedOperationException("Provided unsupported policy.");
         }
     }
+
+    @Override
+    public String getNamespace(Class<?> clazz) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(clazz, this);
+        return entry == null ? null : entry.getNamespace();
+    }
+
+    @Override
+    public String getSet(Class<?> clazz) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(clazz, this);
+        return entry == null ? null : entry.getSetName();
+    }
+
+    @Override
+    public Object getKey(Object obj) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(obj.getClass(), this);
+        return entry == null ? null : entry.getKey(obj);
+    }
+
+    @Override
+    public Key getRecordKey(Object obj) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(obj.getClass(), this);
+        return entry == null ? null : new Key(entry.getNamespace(), entry.getSetName(), Value.get(entry.getKey(obj)));
+    }
 }

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

@@ -45,7 +45,8 @@ public <T> ClassCacheEntry<T> loadClass(@NotNull Class<T> clazz, IBaseAeroMapper
 
     @SuppressWarnings("unchecked")
     public <T> ClassCacheEntry<T> loadClass(@NotNull Class<T> clazz, IBaseAeroMapper mapper, boolean requireRecord) {
-        if (clazz.isPrimitive() || clazz.equals(Object.class) || clazz.equals(String.class)
+        // Clazz can be null if an interface is passed
+        if (clazz == null || clazz.isPrimitive() || clazz.equals(Object.class) || clazz.equals(String.class)
                 || clazz.equals(Character.class) || Number.class.isAssignableFrom(clazz)) {
             return null;
         }

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

@@ -122,16 +122,7 @@ private enum FactoryMethodType {
             throw new NotAnnotatedClass(String.format("Class %s is not augmented by the @AerospikeRecord annotation",
                     clazz.getName()));
         } else if (recordDescription != null) {
-            this.namespace = ParserUtils.getInstance().get(recordDescription.namespace());
-            this.setName = ParserUtils.getInstance().get(recordDescription.set());
-            this.ttl = recordDescription.ttl();
-            this.mapAll = recordDescription.mapAll();
-            this.version = recordDescription.version();
-            this.sendKey = recordDescription.sendKey();
-            this.durableDelete = recordDescription.durableDelete();
-            this.shortenedClassName = recordDescription.shortName();
-            this.factoryClass = recordDescription.factoryClass();
-            this.factoryMethod = recordDescription.factoryMethod();
+            this.setPropertiesFromAerospikeRecord(recordDescription);
         }
         this.config = config;
     }
@@ -142,16 +133,24 @@ public ClassCacheEntry<T> construct() {
             this.overrideSettings(config);
         }
 
+        if (this.namespace == null || this.namespace.isEmpty()) {
+            List<AerospikeRecord> aerospikeInterfaceRecords = this.loadAerospikeRecordsFromInterfaces(this.clazz);
+            for (int i = 0; (this.namespace == null || this.namespace.isEmpty()) && i < aerospikeInterfaceRecords.size(); i++) {
+                this.setPropertiesFromAerospikeRecord(aerospikeInterfaceRecords.get(i));
+            }
+        }
         this.loadFieldsFromClass();
         this.loadPropertiesFromClass();
         this.superClazz = ClassCache.getInstance().loadClass(this.clazz.getSuperclass(), this.mapper, !this.mapAll);
         this.binCount = this.values.size() + (superClazz != null ? superClazz.binCount : 0);
         this.formOrdinalsFromValues();
         Method factoryConstructorMethod = findConstructorFactoryMethod();
-        if (factoryConstructorMethod == null) {
-            this.findConstructor();
-        } else {
-            this.setConstructorFactoryMethod(factoryConstructorMethod);
+        if (!this.clazz.isInterface()) {
+            if (factoryConstructorMethod == null) {
+                this.findConstructor();
+            } else {
+                this.setConstructorFactoryMethod(factoryConstructorMethod);
+            }
         }
         if (StringUtils.isBlank(this.shortenedClassName)) {
             this.shortenedClassName = clazz.getSimpleName();
@@ -236,6 +235,33 @@ public boolean isChildClass() {
         return isChildClass;
     }
 
+    private List<AerospikeRecord> loadAerospikeRecordsFromInterfaces(Class<?> clazz) {
+        List<AerospikeRecord> results = new ArrayList<>();
+        Class<?>[] interfaces = clazz.getInterfaces();
+        for (int i = 0; i < interfaces.length; i++) {
+            Class<?> thisInterface = interfaces[i];
+            AerospikeRecord[] aerospikeRecords = thisInterface.getAnnotationsByType(AerospikeRecord.class);
+            for (int j = 0; j < aerospikeRecords.length; j++) {
+                results.add(aerospikeRecords[j]);
+            }
+            results.addAll(loadAerospikeRecordsFromInterfaces(thisInterface));
+        }
+        return results;
+    }
+    
+    private void setPropertiesFromAerospikeRecord(AerospikeRecord recordDescription) {
+        this.namespace = ParserUtils.getInstance().get(recordDescription.namespace());
+        this.setName = ParserUtils.getInstance().get(recordDescription.set());
+        this.ttl = recordDescription.ttl();
+        this.mapAll = recordDescription.mapAll();
+        this.version = recordDescription.version();
+        this.sendKey = recordDescription.sendKey();
+        this.durableDelete = recordDescription.durableDelete();
+        this.shortenedClassName = recordDescription.shortName();
+        this.factoryClass = recordDescription.factoryClass();
+        this.factoryMethod = recordDescription.factoryMethod();
+    }
+
     private void checkRecordSettingsAgainstSuperClasses() {
         if (!StringUtils.isBlank(this.namespace) && !StringUtils.isBlank(this.setName)) {
             // This class defines its own namespace + set, it is only a child class if its closest named superclass is the same as ours.

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

@@ -7,6 +7,7 @@
 
 import com.aerospike.client.AerospikeException;
 import com.aerospike.client.IAerospikeClient;
+import com.aerospike.client.Key;
 import com.aerospike.client.Operation;
 import com.aerospike.client.policy.BatchPolicy;
 import com.aerospike.client.policy.Policy;
@@ -392,5 +393,35 @@ public interface IAeroMapper extends IBaseAeroMapper {
      */
     <T> VirtualList<T> asBackedList(@NotNull Class<?> owningClazz, @NotNull Object key, @NotNull String binName, Class<T> elementClazz);
 
+    /**
+     * Get the IAerospikeClient which was used to create this mapper.
+     * @return the underlying mapper.
+     */
     IAerospikeClient getClient();
+    
+    /**
+     * Get the namespace associated with the passed class
+     * @param clazz - the class to retrieve the namespace of
+     * @return the namespace
+     */
+    String getNamespace(Class<?> clazz);
+
+    /**
+     * Get the set associated with the passed class
+     * @param clazz - the class to retrieve the set of
+     * @return the set
+     */
+    String getSet(Class<?> clazz);
+    
+    /**
+     * Get the primary id associated with the passed object
+     */
+    Object getKey(Object obj);
+    
+    /**
+     * Get the Aerospike Key used to read the record associated with the passed key
+     * @param obj - the object to return the key of
+     * @return the key which could be used to retrieve this record.
+     */
+    Key getRecordKey(Object obj);
 }

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

@@ -1,17 +1,24 @@
 package com.aerospike.mapper.tools;
 
+import java.util.function.Function;
+
+import javax.validation.constraints.NotNull;
+
 import com.aerospike.client.AerospikeException;
+import com.aerospike.client.Key;
 import com.aerospike.client.Operation;
-import com.aerospike.client.policy.*;
+import com.aerospike.client.policy.BatchPolicy;
+import com.aerospike.client.policy.Policy;
+import com.aerospike.client.policy.QueryPolicy;
+import com.aerospike.client.policy.ScanPolicy;
+import com.aerospike.client.policy.WritePolicy;
 import com.aerospike.client.query.Filter;
 import com.aerospike.client.reactor.IAerospikeReactorClient;
 import com.aerospike.mapper.tools.virtuallist.ReactiveVirtualList;
+
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-import javax.validation.constraints.NotNull;
-import java.util.function.Function;
-
 public interface IReactiveAeroMapper extends IBaseAeroMapper {
 
     /**
@@ -321,4 +328,30 @@ public interface IReactiveAeroMapper extends IBaseAeroMapper {
     <T> ReactiveVirtualList<T> asBackedList(@NotNull Class<?> owningClazz, @NotNull Object key, @NotNull String binName, Class<T> elementClazz);
 
     IAerospikeReactorClient getReactorClient();
+    /**
+     * Get the namespace associated with the passed class
+     * @param clazz - the class to retrieve the namespace of
+     * @return the namespace
+     */
+    <T> Mono<String> getNamespace(Class<T> clazz);
+
+    /**
+     * Get the set associated with the passed class
+     * @param clazz - the class to retrieve the set of
+     * @return the set
+     */
+    <T> Mono<String> getSet(Class<T> clazz);
+    
+    /**
+     * Get the primary id associated with the passed object
+     */
+    Mono<Object> getKey(Object obj);
+    
+    /**
+     * Get the Aerospike Key used to read the record associated with the passed key
+     * 
+     * @param obj - the object to return the key of
+     * @return the key which could be used to retrieve this record.
+     */
+    Mono<Key> getRecordKey(Object obj);
 }

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

@@ -556,4 +556,28 @@ private Throwable translateError(Throwable e) {
         }
         return e;
     }
+    
+    @Override
+    public <T> Mono<String> getNamespace(Class<T> clazz) {
+        ClassCacheEntry<T> entry = MapperUtils.getEntryAndValidateNamespace(clazz, this);
+        return entry == null ? null : Mono.just(entry.getNamespace());
+    }
+
+    @Override
+    public <T> Mono<String> getSet(Class<T> clazz) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(clazz, this);
+        return entry == null ? null : Mono.just(entry.getSetName());
+    }
+
+    @Override
+    public Mono<Object> getKey(Object obj) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(obj.getClass(), this);
+        return entry == null ? null : Mono.just(entry.getKey(obj));
+    }
+
+    @Override
+    public Mono<Key> getRecordKey(Object obj) {
+        ClassCacheEntry<?> entry = ClassCache.getInstance().loadClass(obj.getClass(), this);
+        return entry == null ? null : Mono.just(new Key(entry.getNamespace(), entry.getSetName(), Value.get(entry.getKey(obj))));
+    }
 }