Properties of inherited models can be used on different child models

Author: rPraml

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

@@ -668,6 +668,33 @@ public void setTenantValue(EntityBean entityBean, Object tenantId) {
     setValue(entityBean, tenantId);
   }
 
+  /**
+   * By default, getIntercept and setIntercept will check, if the passed bean is an instance of descriptor type.
+   * <p>
+   * If the property is not part of the type hierarchy (i.e. is this property from this descriptor)
+   * an UnsuppoertedOperation is thrown.
+   * <p>
+   * If inheritance is involved, this method returns false instead of an exception, if the property might exist in
+   * one of the child beans. This is necessary for getIntercept, as it returns <code>null</code> in this case.
+   * @return true if property can be
+   */
+  private boolean checkPropertyAccess(EntityBean bean) {
+    if (bean == null || descriptor.type().isInstance(bean)) { // null = fall through - NPE is catched later.
+      return true;
+    }
+    InheritInfo inheritInfo = descriptor.inheritInfo();
+    if (inheritInfo == null || inheritInfo.isRoot() || !inheritInfo.getRoot().getType().isInstance(bean)) {
+      throw new IllegalArgumentException(propertyIncomatibleMsg(bean));
+    } else {
+      return false;
+    }
+  }
+
+  private String propertyIncomatibleMsg(EntityBean bean) {
+    String beanType = bean == null ? "null" : bean.getClass().getName();
+    return "Property " + name + " on [" + descriptor + "] is incompatible with type[" + beanType + "]";
+  }
+
   /**
    * Set the value of the property without interception or
    * PropertyChangeSupport.
@@ -684,6 +711,9 @@ public void setValue(EntityBean bean, Object value) {
    * Set the value of the property.
    */
   public void setValueIntercept(EntityBean bean, Object value) {
+    if (!checkPropertyAccess(bean)) {
+      throw new IllegalArgumentException(propertyIncomatibleMsg(bean));
+    }
     try {
       setter.setIntercept(bean, value);
     } catch (Exception ex) {
@@ -795,6 +825,9 @@ public Object getValue(EntityBean bean) {
   }
 
   public Object getValueIntercept(EntityBean bean) {
+    if (!checkPropertyAccess(bean)) {
+      return null;
+    }
     try {
       return getter.getIntercept(bean);
     } catch (Exception ex) {

ebean-test/src/test/java/org/tests/inheritance/TestPropertyAccess.java

@@ -0,0 +1,118 @@
+package org.tests.inheritance;
+
+import io.ebean.DB;
+import io.ebean.plugin.ExpressionPath;
+import org.junit.jupiter.api.Test;
+import org.tests.model.basic.*;
+
+import java.sql.Timestamp;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+/**
+ * @author Roland Praml, FOCONIS AG
+ */
+public class TestPropertyAccess {
+
+
+  private ExpressionPath custCretime = DB.getDefault().pluginApi().beanType(Customer.class).expressionPath("cretime");
+  private ExpressionPath custName = DB.getDefault().pluginApi().beanType(Customer.class).expressionPath("name");
+  // Note: Animal.name is only present in "Cat" not in "Dog"
+  private ExpressionPath animalName = DB.getDefault().pluginApi().beanType(Animal.class).expressionPath("name");
+  private ExpressionPath productName = DB.getDefault().pluginApi().beanType(Product.class).expressionPath("name");
+  private ExpressionPath animalSpecies = DB.getDefault().pluginApi().beanType(Animal.class).expressionPath("species");
+
+  @Test
+  void testOnInheritance() {
+    Cat cat = new Cat();
+    cat.setName("Tom");
+    DB.save(cat);
+
+    Dog dog = new Dog();
+    dog.setRegistrationNumber("FOO");
+    DB.save(dog);
+
+
+    Animal animal = DB.find(Animal.class, cat.getId());
+    assertThat(animalName.pathGet(animal)).isEqualTo("Tom");
+
+    animal = DB.find(Animal.class, dog.getId());
+    assertThat(animalName.pathGet(animal)).isNull();
+
+    animalName.pathSet(cat, "Jerry");
+    assertThat(cat.getName()).isEqualTo("Jerry");
+
+    assertThatThrownBy(() -> animalName.pathSet(dog, "Jerry"))
+      .isInstanceOf(IllegalArgumentException.class);
+
+    animalSpecies.pathSet(cat, "Angora");
+    animalSpecies.pathSet(dog, "Bulldog");
+
+    assertThat(cat.getSpecies()).isEqualTo("Angora");
+    assertThat(dog.getSpecies()).isEqualTo("Bulldog");
+  }
+
+  @Test
+  void testOnMappedSuperClass() {
+    Customer cust = new Customer();
+
+    Timestamp ts = new Timestamp(123);
+    custCretime.pathSet(cust, ts);
+    assertThat(custCretime.pathGet(cust)).isEqualTo(ts);
+
+    custName.pathSet(cust, "Roland");
+    assertThat(custName.pathGet(cust)).isEqualTo("Roland");
+
+  }
+
+  @Test
+  void testOnPlainBean() {
+    Product product = new Product();
+
+    productName.pathSet(product, "Roland");
+    assertThat(productName.pathGet(product)).isEqualTo("Roland");
+  }
+
+  @Test
+  void testOnContactGroup() {
+    ContactGroup cg = new ContactGroup();
+
+    // CHECKEM: Ist it OK to us the "custCretime" on "contactGroup"
+    assertThatThrownBy(() -> custCretime.pathGet(cg)).isInstanceOf(IllegalArgumentException.class);
+  }
+
+  @Test
+  void testOnCrossUsage() {
+    Product product = new Product();
+    Customer cust = new Customer();
+    Cat cat = new Cat();
+    Dog dog = new Dog();
+
+
+    assertThatThrownBy(() -> custCretime.pathGet(product)).isInstanceOf(IllegalArgumentException.class);
+    custCretime.pathGet(cust);
+    assertThatThrownBy(() -> custCretime.pathGet(cat)).isInstanceOf(IllegalArgumentException.class);
+    assertThatThrownBy(() -> custCretime.pathGet(dog)).isInstanceOf(IllegalArgumentException.class);
+
+    assertThatThrownBy(() -> custName.pathGet(product)).isInstanceOf(IllegalArgumentException.class);
+    custName.pathGet(cust);
+    assertThatThrownBy(() -> custName.pathGet(cat)).isInstanceOf(IllegalArgumentException.class);
+    assertThatThrownBy(() -> custName.pathGet(dog)).isInstanceOf(IllegalArgumentException.class);
+
+    assertThatThrownBy(() -> animalName.pathGet(product)).isInstanceOf(IllegalArgumentException.class);
+    assertThatThrownBy(() -> animalName.pathGet(cust)).isInstanceOf(IllegalArgumentException.class);
+    animalName.pathGet(cat);
+    animalName.pathGet(dog);
+
+    productName.pathGet(product);
+    assertThatThrownBy(() -> productName.pathGet(cust)).isInstanceOf(IllegalArgumentException.class);
+    assertThatThrownBy(() -> productName.pathGet(cat)).isInstanceOf(IllegalArgumentException.class);
+    assertThatThrownBy(() -> productName.pathGet(dog)).isInstanceOf(IllegalArgumentException.class);
+
+    assertThatThrownBy(() -> animalSpecies.pathGet(product)).isInstanceOf(IllegalArgumentException.class);
+    assertThatThrownBy(() -> animalSpecies.pathGet(cust)).isInstanceOf(IllegalArgumentException.class);
+    animalSpecies.pathGet(cat);
+    animalSpecies.pathGet(dog);
+  }
+}