/**
* Finds a method by reflection. This iterates all methods of the class, comparing names and
* parameter types. Unlike the method Class.getMethod(String, Class ...), this method is able to
* match primitive and wrapper types. If no appropriate method is found, a ConfigurationError is
* raised.
*
* @param type
* @param methodName
* @param paramTypes
* @return a method with matching names and parameters
*/
public static Method getMethod(Class<?> type, String methodName, Class<?>... paramTypes) {
Method method = findMethod(type, methodName, paramTypes);
if (method == null)
throw new ConfigurationError(
"method not found in class "
+ type.getName()
+ ": "
+ methodName
+ '('
+ ArrayFormat.format(paramTypes)
+ ')');
return method;
}
@SuppressWarnings({"unchecked", "rawtypes"})
public static <T> T newInstance(Class<T> type, boolean strict, Object... parameters) {
if (parameters.length == 0) return newInstanceFromDefaultConstructor(type);
Constructor<T> constructorToUse = null;
try {
Constructor<T>[] constructors = (Constructor<T>[]) type.getConstructors();
List<Constructor<T>> candidates = new ArrayList<Constructor<T>>(constructors.length);
int paramCount = parameters.length;
for (Constructor<T> constructor : constructors)
if (constructor.getParameterTypes().length == paramCount) candidates.add(constructor);
if (candidates.size() == 1) constructorToUse = candidates.get(0);
else if (candidates.size() == 0)
throw new ConfigurationError(
"No constructor with " + paramCount + " parameters found for " + type);
else {
// there are several candidates - find the first one with matching types
Class<?>[] paramTypes = new Class[parameters.length];
for (int i = 0; i < parameters.length; i++) paramTypes[i] = parameters[i].getClass();
for (Constructor c : type.getConstructors()) {
if (typesMatch(c.getParameterTypes(), paramTypes)) {
constructorToUse = c;
break;
}
}
// there is no ideal match
if (constructorToUse == null) {
if (strict)
throw new NoSuchMethodException(
"No appropriate constructor found: "
+ type
+ '('
+ ArrayFormat.format(", ", paramTypes)
+ ')');
Exception mostRecentException = null;
for (Constructor<T> candidate : candidates) {
try {
return newInstance(candidate, strict, parameters);
} catch (Exception e) {
mostRecentException = e;
logger.warn("Exception in constructor call: " + candidate, e);
continue; // ignore exception and try next constructor
}
}
// no constructor could be called without exception
String errMsg =
(mostRecentException != null
? "None of these constructors could be called without exception: "
+ candidates
+ ", latest exception: "
+ mostRecentException
: type
+ " has no appropriate constructor for the arguments "
+ ArrayFormat.format(", ", parameters));
throw new ConfigurationError(errMsg);
}
}
if (!strict) parameters = convertArray(parameters, constructorToUse.getParameterTypes());
return newInstance(constructorToUse, parameters);
} catch (SecurityException e) {
throw ExceptionMapper.configurationException(e, constructorToUse);
} catch (NoSuchMethodException e) {
throw ExceptionMapper.configurationException(e, type);
}
}
