/**
* Convert an annotation member value from JDT into Reflection, and from whatever its actual type
* is into whatever type the reflective invoker of a method is expecting.
*
* <p>Only certain types are permitted as member values. Specifically, a member must be a
* constant, and must be either a primitive type, String, Class, an enum constant, an annotation,
* or an array of any of those. Multidimensional arrays are not permitted.
*
* @param actualValue the value as represented by {@link ElementValuePair#getValue()}
* @param actualType the return type of the corresponding {@link MethodBinding}
* @param expectedType the type that the reflective method invoker is expecting
* @return an object of the expected type representing the annotation member value, or an
* appropriate dummy value (such as null) if no value is available
*/
private Object getReflectionValue(
Object actualValue, TypeBinding actualType, Class<?> expectedType) {
if (null == expectedType) {
// With no expected type, we can't even guess at a conversion
return null;
}
if (null == actualValue) {
// Return a type-appropriate equivalent of null
return Factory.getMatchingDummyValue(expectedType);
}
if (expectedType.isArray()) {
if (Class.class.equals(expectedType.getComponentType())) {
// package Class[]-valued return as a MirroredTypesException
if (actualType.isArrayType()
&& actualValue instanceof Object[]
&& ((ArrayBinding) actualType).leafComponentType.erasure().id
== TypeIds.T_JavaLangClass) {
Object[] bindings = (Object[]) actualValue;
List<TypeMirror> mirrors = new ArrayList<>(bindings.length);
for (int i = 0; i < bindings.length; ++i) {
if (bindings[i] instanceof TypeBinding) {
mirrors.add(_env.getFactory().newTypeMirror((TypeBinding) bindings[i]));
}
}
throw new MirroredTypesException(mirrors);
}
// TODO: actual value is not a TypeBinding[]. Should we return a TypeMirror[] around an
// ErrorType?
return null;
}
// Handle arrays of types other than Class, e.g., int[], MyEnum[], ...
return convertJDTArrayToReflectionArray(actualValue, actualType, expectedType);
} else if (Class.class.equals(expectedType)) {
// package the Class-valued return as a MirroredTypeException
if (actualValue instanceof TypeBinding) {
TypeMirror mirror = _env.getFactory().newTypeMirror((TypeBinding) actualValue);
throw new MirroredTypeException(mirror);
} else {
// TODO: actual value is not a TypeBinding. Should we return a TypeMirror around an
// ErrorType?
return null;
}
} else {
// Handle unitary values of type other than Class, e.g., int, MyEnum, ...
return convertJDTValueToReflectionType(actualValue, actualType, expectedType);
}
}
/**
* Convert a JDT annotation value as obtained from ElementValuePair.getValue() (e.g., IntConstant,
* FieldBinding, etc.) to the type expected by a reflective method invocation (e.g., int, an enum
* constant, etc.).
*
* @return a value of type {@code expectedType}, or a dummy value of that type if the actual value
* cannot be converted.
*/
private Object convertJDTValueToReflectionType(
Object jdtValue, TypeBinding actualType, Class<?> expectedType) {
if (expectedType.isPrimitive() || String.class.equals(expectedType)) {
if (jdtValue instanceof Constant) {
if (boolean.class.equals(expectedType)) {
return ((Constant) jdtValue).booleanValue();
} else if (byte.class.equals(expectedType)) {
return ((Constant) jdtValue).byteValue();
} else if (char.class.equals(expectedType)) {
return ((Constant) jdtValue).charValue();
} else if (double.class.equals(expectedType)) {
return ((Constant) jdtValue).doubleValue();
} else if (float.class.equals(expectedType)) {
return ((Constant) jdtValue).floatValue();
} else if (int.class.equals(expectedType)) {
return ((Constant) jdtValue).intValue();
} else if (long.class.equals(expectedType)) {
return ((Constant) jdtValue).longValue();
} else if (short.class.equals(expectedType)) {
return ((Constant) jdtValue).shortValue();
} else if (String.class.equals(expectedType)) {
return ((Constant) jdtValue).stringValue();
}
}
// Primitive or string is expected, but our actual value cannot be coerced into one.
// TODO: if the actual value is an array of primitives, should we unpack the first one?
return Factory.getMatchingDummyValue(expectedType);
} else if (expectedType.isEnum()) {
Object returnVal = null;
if (actualType != null && actualType.isEnum() && jdtValue instanceof FieldBinding) {
FieldBinding binding = (FieldBinding) jdtValue;
try {
Field returnedField = null;
returnedField = expectedType.getField(new String(binding.name));
if (null != returnedField) {
returnVal = returnedField.get(null);
}
} catch (NoSuchFieldException nsfe) {
// return null
} catch (IllegalAccessException iae) {
// return null
}
}
return null == returnVal ? Factory.getMatchingDummyValue(expectedType) : returnVal;
} else if (expectedType.isAnnotation()) {
// member value is expected to be an annotation type. Wrap it in an Annotation proxy.
if (actualType.isAnnotationType() && jdtValue instanceof AnnotationBinding) {
AnnotationMirrorImpl annoMirror =
(AnnotationMirrorImpl)
_env.getFactory().newAnnotationMirror((AnnotationBinding) jdtValue);
return Proxy.newProxyInstance(
expectedType.getClassLoader(), new Class[] {expectedType}, annoMirror);
} else {
// No way to cast a non-annotation value to an annotation type; return null to caller
return null;
}
} else {
return Factory.getMatchingDummyValue(expectedType);
}
}
/**
* Convert an array of JDT types as obtained from ElementValuePair.getValue() (e.g., an Object[]
* containing IntConstant elements) to the type expected by a reflective method invocation (e.g.,
* int[]).
*
* <p>This does not handle arrays of Class, but it does handle primitives, enum constants, and
* types such as String.
*
* @param jdtValue the actual value returned by ElementValuePair.getValue() or
* MethodBinding.getDefault()
* @param jdtType the return type of the annotation method binding
* @param expectedType the type that the invoker of the method is expecting; must be an array type
* @return an Object which is, e.g., an int[]; or null, if an array cannot be created.
*/
private Object convertJDTArrayToReflectionArray(
Object jdtValue, TypeBinding jdtType, Class<?> expectedType) {
assert null != expectedType && expectedType.isArray();
if (!jdtType.isArrayType()) {
// the compiler says that the type binding isn't an array type; this probably means
// that there's some sort of syntax error.
return null;
}
Object[] jdtArray;
// See bug 261969: it's legal to pass a solo element for an array-typed value
if (jdtValue != null && !(jdtValue instanceof Object[])) {
// Create an array of the expected type
jdtArray = (Object[]) Array.newInstance(jdtValue.getClass(), 1);
jdtArray[0] = jdtValue;
} else {
jdtArray = (Object[]) jdtValue;
}
TypeBinding jdtLeafType = jdtType.leafComponentType();
Class<?> expectedLeafType = expectedType.getComponentType();
final int length = jdtArray.length;
final Object returnArray = Array.newInstance(expectedLeafType, length);
for (int i = 0; i < length; ++i) {
Object jdtElementValue = jdtArray[i];
if (expectedLeafType.isPrimitive() || String.class.equals(expectedLeafType)) {
if (jdtElementValue instanceof Constant) {
if (boolean.class.equals(expectedLeafType)) {
Array.setBoolean(returnArray, i, ((Constant) jdtElementValue).booleanValue());
} else if (byte.class.equals(expectedLeafType)) {
Array.setByte(returnArray, i, ((Constant) jdtElementValue).byteValue());
} else if (char.class.equals(expectedLeafType)) {
Array.setChar(returnArray, i, ((Constant) jdtElementValue).charValue());
} else if (double.class.equals(expectedLeafType)) {
Array.setDouble(returnArray, i, ((Constant) jdtElementValue).doubleValue());
} else if (float.class.equals(expectedLeafType)) {
Array.setFloat(returnArray, i, ((Constant) jdtElementValue).floatValue());
} else if (int.class.equals(expectedLeafType)) {
Array.setInt(returnArray, i, ((Constant) jdtElementValue).intValue());
} else if (long.class.equals(expectedLeafType)) {
Array.setLong(returnArray, i, ((Constant) jdtElementValue).longValue());
} else if (short.class.equals(expectedLeafType)) {
Array.setShort(returnArray, i, ((Constant) jdtElementValue).shortValue());
} else if (String.class.equals(expectedLeafType)) {
Array.set(returnArray, i, ((Constant) jdtElementValue).stringValue());
}
} else {
// Primitive or string is expected, but our actual value cannot be coerced into one.
// TODO: if the actual value is an array of primitives, should we unpack the first one?
Factory.setArrayMatchingDummyValue(returnArray, i, expectedLeafType);
}
} else if (expectedLeafType.isEnum()) {
Object returnVal = null;
if (jdtLeafType != null
&& jdtLeafType.isEnum()
&& jdtElementValue instanceof FieldBinding) {
FieldBinding binding = (FieldBinding) jdtElementValue;
try {
Field returnedField = null;
returnedField = expectedLeafType.getField(new String(binding.name));
if (null != returnedField) {
returnVal = returnedField.get(null);
}
} catch (NoSuchFieldException nsfe) {
// return null
} catch (IllegalAccessException iae) {
// return null
}
}
Array.set(returnArray, i, returnVal);
} else if (expectedLeafType.isAnnotation()) {
// member value is expected to be an annotation type. Wrap it in an Annotation proxy.
Object returnVal = null;
if (jdtLeafType.isAnnotationType() && jdtElementValue instanceof AnnotationBinding) {
AnnotationMirrorImpl annoMirror =
(AnnotationMirrorImpl)
_env.getFactory().newAnnotationMirror((AnnotationBinding) jdtElementValue);
returnVal =
Proxy.newProxyInstance(
expectedLeafType.getClassLoader(), new Class[] {expectedLeafType}, annoMirror);
}
Array.set(returnArray, i, returnVal);
} else {
Array.set(returnArray, i, null);
}
}
return returnArray;
}
@Override
public DeclaredType getAnnotationType() {
return (DeclaredType) _env.getFactory().newTypeMirror(_binding.getAnnotationType());
}