@Nullable
public static Type resolveVariable(
TypeVariable variable, final Class classType, boolean resolveInInterfacesOnly) {
final Class aClass = getRawType(classType);
int index = ArrayUtilRt.find(ReflectionCache.getTypeParameters(aClass), variable);
if (index >= 0) {
return variable;
}
final Class[] classes = ReflectionCache.getInterfaces(aClass);
final Type[] genericInterfaces = ReflectionCache.getGenericInterfaces(aClass);
for (int i = 0; i <= classes.length; i++) {
Class anInterface;
if (i < classes.length) {
anInterface = classes[i];
} else {
anInterface = ReflectionCache.getSuperClass(aClass);
if (resolveInInterfacesOnly || anInterface == null) {
continue;
}
}
final Type resolved = resolveVariable(variable, anInterface);
if (resolved instanceof Class || resolved instanceof ParameterizedType) {
return resolved;
}
if (resolved instanceof TypeVariable) {
final TypeVariable typeVariable = (TypeVariable) resolved;
index = ArrayUtilRt.find(ReflectionCache.getTypeParameters(anInterface), typeVariable);
if (index < 0) {
LOG.error(
"Cannot resolve type variable:\n"
+ "typeVariable = "
+ typeVariable
+ "\n"
+ "genericDeclaration = "
+ declarationToString(typeVariable.getGenericDeclaration())
+ "\n"
+ "searching in "
+ declarationToString(anInterface));
}
final Type type =
i < genericInterfaces.length ? genericInterfaces[i] : aClass.getGenericSuperclass();
if (type instanceof Class) {
return Object.class;
}
if (type instanceof ParameterizedType) {
return getActualTypeArguments((ParameterizedType) type)[index];
}
throw new AssertionError("Invalid type: " + type);
}
}
return null;
}
@Nullable
public static Class<?> substituteGenericType(final Type genericType, final Type classType) {
if (genericType instanceof TypeVariable) {
final Class<?> aClass = getRawType(classType);
final Type type = resolveVariable((TypeVariable) genericType, aClass);
if (type instanceof Class) {
return (Class) type;
}
if (type instanceof ParameterizedType) {
return (Class<?>) ((ParameterizedType) type).getRawType();
}
if (type instanceof TypeVariable && classType instanceof ParameterizedType) {
final int index = ArrayUtilRt.find(ReflectionCache.getTypeParameters(aClass), type);
if (index >= 0) {
return getRawType(getActualTypeArguments((ParameterizedType) classType)[index]);
}
}
} else {
return getRawType(genericType);
}
return null;
}