public static <T> T create(Class<T> clazz, Class<? super T> parent) {
try {
ReflectionFactory rf = ReflectionFactory.getReflectionFactory();
Constructor objDef = parent.getDeclaredConstructor();
Constructor intConstr = rf.newConstructorForSerialization(clazz, objDef);
return clazz.cast(intConstr.newInstance());
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new IllegalStateException("Cannot create object", e);
}
}
public SunReflectionFactoryInstantiator(final Class type) {
final ReflectionFactory reflectionFactory = ReflectionFactory.getReflectionFactory();
Constructor javaLangObjectConstructor;
try {
javaLangObjectConstructor = Object.class.getConstructor((Class[]) null);
} catch (final NoSuchMethodException e) {
throw new Error("Cannot find constructor for java.lang.Object!");
}
this.mungedConstructor =
reflectionFactory.newConstructorForSerialization(type, javaLangObjectConstructor);
this.mungedConstructor.setAccessible(true);
}
public static void setStaticFinalField(Field field, Object value)
throws NoSuchFieldException, IllegalAccessException {
field.setAccessible(true);
final Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
int modifiers = modifiersField.getInt(field);
modifiers &= ~Modifier.FINAL;
modifiersField.setInt(field, modifiers);
final FieldAccessor fieldAccessor = reflectionFactory.newFieldAccessor(field, false);
fieldAccessor.set(null, value);
}
public class ReflectionUtil {
private static final ReflectionFactory reflectionFactory =
ReflectionFactory.getReflectionFactory();
public static void setStaticFinalField(Field field, Object value)
throws NoSuchFieldException, IllegalAccessException {
field.setAccessible(true);
final Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
int modifiers = modifiersField.getInt(field);
modifiers &= ~Modifier.FINAL;
modifiersField.setInt(field, modifiers);
final FieldAccessor fieldAccessor = reflectionFactory.newFieldAccessor(field, false);
fieldAccessor.set(null, value);
}
public static <T> T getPrivateField(Object target, String fieldName, Class<T> fieldType)
throws Exception {
Class<?> type = target.getClass();
Field field = getField(fieldName, type);
if (!fieldType.isAssignableFrom(field.getType())) {
throw new IllegalArgumentException(
"Field type does not match " + field.getType() + " is no subclass of " + "" + fieldType);
}
field.setAccessible(true);
return fieldType.cast(field.get(target));
}
private static Field getField(String fieldName, Class<? extends Object> type)
throws NoSuchFieldException {
if (type == null) {
throw new NoSuchFieldException(fieldName);
}
try {
Field field = type.getDeclaredField(fieldName);
if (field != null) {
return field;
}
} catch (NoSuchFieldError e) {
} catch (NoSuchFieldException e) {
}
return getField(fieldName, type.getSuperclass());
}
}
/**
* Constructs an instance even if the corresponding class doesn't have a default constructor.
*
* @param cls A class to instantiate.
* @return A newly allocated instance.
* @throws InvocationTargetException Something went wrong while instantiating.
* @throws IllegalAccessException Something went wrong while instantiating.
* @throws InstantiationException Something went wrong while instantiating.
*/
static Object forceNewInstance(Class cls)
throws InvocationTargetException, IllegalAccessException, InstantiationException {
return ReflectionFactory.getReflectionFactory()
.newConstructorForSerialization(cls, OBJECT_CONSTRUCTOR)
.newInstance();
}
/*
* Bootstrapping protocol between java.lang and java.lang.reflect
* packages
*/
static {
sun.reflect.ReflectionFactory factory =
(sun.reflect.ReflectionFactory)
AccessController.doPrivileged(new ReflectionFactory.GetReflectionFactoryAction());
factory.setLangReflectAccess(new java.lang.reflect.ReflectAccess());
}