Changes DeployCreateProperties to allow processing of inheritance hierarchies with generics

Author: dsa-ferreira

ebean-core/src/main/java/io/ebeaninternal/server/deploy/parse/DeployCreateProperties.java

@@ -11,6 +11,8 @@
 
 import jakarta.persistence.*;
 import java.lang.reflect.*;
+import java.util.HashMap;
+import java.util.Map;
 
 import static java.lang.System.Logger.Level.*;
 
@@ -35,7 +37,7 @@ public DeployCreateProperties(TypeManager typeManager) {
    * Create the appropriate properties for a bean.
    */
   public void createProperties(DeployBeanDescriptor<?> desc) {
-    createProperties(desc, desc.getBeanType(), 0);
+    createProperties(desc, desc.getBeanType(), 0, new HashMap<>());
     desc.sortProperties();
   }
 
@@ -56,15 +58,20 @@ private boolean ignoreFieldByName(String fieldName) {
 
   private boolean ignoreField(Field field) {
     return Modifier.isStatic(field.getModifiers())
-      || Modifier.isTransient(field.getModifiers())
-      || ignoreFieldByName(field.getName());
+        || Modifier.isTransient(field.getModifiers())
+        || ignoreFieldByName(field.getName());
   }
 
   /**
-   * properties the bean properties from Class. Some of these properties may not map to database
+   * properties the bean properties from Class. Some of these properties may not
+   * map to database
    * columns.
    */
-  private void createProperties(DeployBeanDescriptor<?> desc, Class<?> beanType, int level) {
+  private void createProperties(
+      DeployBeanDescriptor<?> desc,
+      Class<?> beanType,
+      int level,
+      Map<TypeVariable<?>, Class<?>> genericTypeMap) {
     if (beanType.equals(Model.class)) {
       // ignore all fields on model (_$dbName)
       return;
@@ -74,7 +81,7 @@ private void createProperties(DeployBeanDescriptor<?> desc, Class<?> beanType, i
       for (int i = 0; i < fields.length; i++) {
         Field field = fields[i];
         if (!ignoreField(field)) {
-          DeployBeanProperty prop = createProp(desc, field, beanType);
+          DeployBeanProperty prop = createProp(desc, field, beanType, genericTypeMap);
           if (prop != null) {
             // set a order that gives priority to inherited properties
             // push Id/EmbeddedId up and CreatedTimestamp/UpdatedTimestamp down
@@ -95,7 +102,7 @@ private void createProperties(DeployBeanDescriptor<?> desc, Class<?> beanType, i
       if (!superClass.equals(Object.class)) {
         // recursively add any properties in the inheritance hierarchy
         // up to the Object.class level...
-        createProperties(desc, superClass, level + 1);
+        createProperties(desc, superClass, level + 1, mapGenerics(beanType));
       }
     } catch (PersistenceException ex) {
       throw ex;
@@ -116,8 +123,13 @@ private DeployBeanProperty createManyType(DeployBeanDescriptor<?> desc, Class<?>
     return new DeployBeanPropertyAssocMany<>(desc, targetType, manyType);
   }
 
-  private DeployBeanProperty createProp(DeployBeanDescriptor<?> desc, Field field) {
-    Class<?> propertyType = field.getType();
+  private DeployBeanProperty createProp(
+      DeployBeanDescriptor<?> desc,
+      Field field,
+      Map<TypeVariable<?>, Class<?>> genericTypeMap) {
+    Class<?> propertyType = field.getGenericType() instanceof TypeVariable<?>
+        ? genericTypeMap.get(field.getGenericType())
+        : field.getType();
     if (isSpecialScalarType(field)) {
       return new DeployBeanProperty(desc, propertyType, field.getGenericType());
     }
@@ -131,7 +143,8 @@ private DeployBeanProperty createProp(DeployBeanDescriptor<?> desc, Field field)
           // not supporting this field (generic type used)
           return null;
         }
-        CoreLog.internal.log(WARNING, "Could not find parameter type (via reflection) on " + desc.getFullName() + " " + field.getName());
+        CoreLog.internal.log(WARNING,
+            "Could not find parameter type (via reflection) on " + desc.getFullName() + " " + field.getName());
       }
       return createManyType(desc, targetType, manyType);
     }
@@ -147,7 +160,8 @@ private DeployBeanProperty createProp(DeployBeanDescriptor<?> desc, Field field)
       return new DeployBeanProperty(desc, propertyType, null, null);
     }
     if (AnnotationUtil.has(field, Convert.class)) {
-      throw new IllegalStateException("No AttributeConverter registered for type " + propertyType + " at " + desc.getFullName() + "." + field.getName());
+      throw new IllegalStateException("No AttributeConverter registered for type " + propertyType + " at "
+          + desc.getFullName() + "." + field.getName());
     }
     try {
       return new DeployBeanPropertyAssocOne<>(desc, propertyType);
@@ -162,18 +176,22 @@ private DeployBeanProperty createProp(DeployBeanDescriptor<?> desc, Field field)
    */
   private boolean isSpecialScalarType(Field field) {
     return (AnnotationUtil.has(field, DbJson.class))
-      || (AnnotationUtil.has(field, DbJsonB.class))
-      || (AnnotationUtil.has(field, DbArray.class))
-      || (AnnotationUtil.has(field, DbMap.class))
-      || (AnnotationUtil.has(field, UnmappedJson.class));
+        || (AnnotationUtil.has(field, DbJsonB.class))
+        || (AnnotationUtil.has(field, DbArray.class))
+        || (AnnotationUtil.has(field, DbMap.class))
+        || (AnnotationUtil.has(field, UnmappedJson.class));
   }
 
   private boolean isTransientField(Field field) {
     return AnnotationUtil.has(field, Transient.class);
   }
 
-  private DeployBeanProperty createProp(DeployBeanDescriptor<?> desc, Field field, Class<?> beanType) {
-    DeployBeanProperty prop = createProp(desc, field);
+  private DeployBeanProperty createProp(
+      DeployBeanDescriptor<?> desc,
+      Field field,
+      Class<?> beanType,
+      Map<TypeVariable<?>, Class<?>> genericTypeMap) {
+    DeployBeanProperty prop = createProp(desc, field, genericTypeMap);
     if (prop == null) {
       // transient annotation on unsupported type
       return null;
@@ -186,7 +204,8 @@ private DeployBeanProperty createProp(DeployBeanDescriptor<?> desc, Field field,
   }
 
   /**
-   * Determine the type of the List,Set or Map. Not been set explicitly so determine this from
+   * Determine the type of the List,Set or Map. Not been set explicitly so
+   * determine this from
    * ParameterizedType.
    */
   private Class<?> determineTargetType(Field field) {
@@ -224,4 +243,40 @@ private Class<?> determineTargetType(Field field) {
     // if targetType is null, then must be set in annotations
     return null;
   }
+
+  private Map<TypeVariable<?>, Class<?>> mapGenerics(Class<?> clazz) {
+    Type genericSuperclass = clazz.getGenericSuperclass();
+    if (!(genericSuperclass instanceof ParameterizedType)) {
+      return new HashMap<>();
+    }
+
+    ParameterizedType parameterized = (ParameterizedType) genericSuperclass;
+    TypeVariable<?>[] typeVars = ((Class<?>) parameterized.getRawType()).getTypeParameters();
+    Type[] actualTypes = parameterized.getActualTypeArguments();
+
+    Map<TypeVariable<?>, Class<?>> typeMap = new HashMap<>();
+    for (int i = 0; i < typeVars.length; i++) {
+      Type actual = actualTypes[i];
+      Class<?> resolvedClass = resolveToClass(actual);
+      if (resolvedClass != null) {
+        typeMap.put(typeVars[i], resolvedClass);
+      } else {
+        // ignore
+      }
+    }
+    return typeMap;
+  }
+
+  private static Class<?> resolveToClass(Type type) {
+    if (type instanceof Class<?>) {
+      return (Class<?>) type;
+    } else if (type instanceof ParameterizedType) {
+      ParameterizedType pType = (ParameterizedType) type;
+      Type raw = pType.getRawType();
+      if (raw instanceof Class<?>) {
+        return (Class<?>) raw;
+      }
+    }
+    return null;
+  }
 }