How to use

castOrCopy

method

in

org.apache.sis.internal.util.CheckedArrayList

/**
 * Creates a new association of the given role initialized to the given values.
 *
 * @param role   Information about the association.
 * @param values The initial values, or {@code null} for initializing to an empty list.
 */
MultiValuedAssociation(final DefaultAssociationRole role, final Object values) {
  super(role);
  if (values == null) {
    this.values = new CheckedArrayList<>(AbstractFeature.class);
  } else {
    this.values = CheckedArrayList.castOrCopy((CheckedArrayList<?>) values, AbstractFeature.class);
  }
}

/**
 * Creates a new association of the given role initialized to the given values.
 *
 * @param role   Information about the association.
 * @param values The initial values, or {@code null} for initializing to an empty list.
 */
MultiValuedAssociation(final DefaultAssociationRole role, final Object values) {
  super(role);
  if (values == null) {
    this.values = new CheckedArrayList<>(AbstractFeature.class);
  } else {
    this.values = CheckedArrayList.castOrCopy((CheckedArrayList<?>) values, AbstractFeature.class);
  }
}

/**
 * Verifies the validity of the given attribute value, and returns the value to store in the feature.
 * An attribute:
 * <ul>
 *   <li>May be a singleton,  in which case the value class is verified.</li>
 *   <li>May be a collection, in which case the class each elements in the collection is verified.</li>
 * </ul>
 *
 * @param  value  the value, which shall be non-null.
 */
private static <T> Object verifyAttributeValue(final DefaultAttributeType<T> type, final Object value) {
  final Class<T> valueClass = type.getValueClass();
  final boolean isSingleton = Field.isSingleton(type.getMaximumOccurs());
  if (valueClass.isInstance(value)) {
    return isSingleton ? value : singletonList(valueClass, type.getMinimumOccurs(), value);
  } else if (!isSingleton && value instanceof Collection<?>) {
    return CheckedArrayList.castOrCopy((Collection<?>) value, valueClass);
  } else {
    throw new ClassCastException(illegalValueClass(type, valueClass, value));
  }
}

/**
 * Verifies the validity of the given attribute value, and returns the value to store in the feature.
 * An attribute:
 * <ul>
 *   <li>May be a singleton,  in which case the value class is verified.</li>
 *   <li>May be a collection, in which case the class each elements in the collection is verified.</li>
 * </ul>
 *
 * @param  value  the value, which shall be non-null.
 */
private static <T> Object verifyAttributeValue(final DefaultAttributeType<T> type, final Object value) {
  final Class<T> valueClass = type.getValueClass();
  final boolean isSingleton = Field.isSingleton(type.getMaximumOccurs());
  if (valueClass.isInstance(value)) {
    return isSingleton ? value : singletonList(valueClass, type.getMinimumOccurs(), value);
  } else if (!isSingleton && value instanceof Collection<?>) {
    return CheckedArrayList.castOrCopy((Collection<?>) value, valueClass);
  } else {
    throw new ClassCastException(illegalValueClass(type, valueClass, value));
  }
}

  return CheckedArrayList.castOrCopy((Collection<?>) value, AbstractFeature.class);
} else {
  throw new ClassCastException(illegalValueClass(role, AbstractFeature.class, value));

  return CheckedArrayList.castOrCopy((Collection<?>) value, AbstractFeature.class);
} else {
  throw new ClassCastException(illegalValueClass(role, AbstractFeature.class, value));

  /**
   * Tests {@link CheckedArrayList#castOrCopy(Collection, Class)}.
   */
  @Test
  @DependsOnMethod("testAddAll")
  public void testCastOrCopy() {
    assertNull(CheckedArrayList.castOrCopy(null, String.class));
    final List<String> fruits = Arrays.asList("Apple", "Orange", "Raisin");
    final CheckedArrayList<String> asStrings = CheckedArrayList.castOrCopy(fruits, String.class);
    assertEquals ("Should have the given element type.", String.class, asStrings.getElementType());
    assertNotSame("Should have created a new instance.", fruits, asStrings);
    assertEquals ("Should contain the same data.",       fruits, asStrings);
    assertSame   ("Should cast existing instance.", asStrings, CheckedArrayList.castOrCopy(asStrings, String.class));

    final CheckedArrayList<CharSequence> asChars = CheckedArrayList.castOrCopy(asStrings, CharSequence.class);
    assertEquals ("Should have the given element type.", CharSequence.class, asChars.getElementType());
    assertNotSame("Should have created a new instance.", asStrings, asChars);
    assertEquals ("Should contain the same data.",       asStrings, asChars);
    assertEquals ("Should contain the same data.",       fruits,    asChars);

    try {
      CheckedArrayList.castOrCopy(asChars, Integer.class);
      fail("Should not be allowed to cast String to Integer.");
    } catch (ClassCastException e) {
      final String message = e.getMessage();
      assertTrue(message, message.contains("String"));
      assertTrue(message, message.contains("Integer"));
    }
  }
}