/**
* Returns the value of the given <code>field</code> in the given <code>object</code>. If
* necessary, the field is made accessible, assuming the security manager allows it.
*
* @param field The field containing the value
* @param object The object to retrieve the field's value from
* @return the value of the <code>field</code> in the <code>object</code>
* @throws IllegalStateException if the field is not accessible and the security manager doesn't
* allow it to be made accessible
*/
public static Object getFieldValue(Field field, Object object) {
ensureAccessible(field);
try {
return field.get(object);
} catch (IllegalAccessException ex) {
throw new IllegalStateException("Unable to access field.", ex);
}
}
/**
* Creates a MethodMessageHandler for the given <code>method</code>, using given <code>
* explicitPayloadType</code> (if not <code>null</code>) defining the payload of the message it
* supports. If <code>null</code>, the payload type is deducted from the first parameter of the
* method.
*
* @param method The method to create a Handler for
* @param explicitPayloadType The payload type explicitly defined on the method, or <code>null
* </code>
* @return The MethodMessageHandler implementation for the given method.
* @throws UnsupportedHandlerException if the given method is not suitable as a Handler
*/
public static MethodMessageHandler createFor(Method method, Class<?> explicitPayloadType) {
ParameterResolver[] resolvers =
findResolvers(
method.getAnnotations(),
method.getParameterTypes(),
method.getParameterAnnotations(),
explicitPayloadType == null);
Class<?> payloadType = explicitPayloadType;
if (explicitPayloadType == null) {
Class<?> firstParameter = method.getParameterTypes()[0];
if (Message.class.isAssignableFrom(firstParameter)) {
payloadType = Object.class;
} else {
payloadType = firstParameter;
}
}
ensureAccessible(method);
validate(method, resolvers);
return new MethodMessageHandler(method, resolvers, payloadType);
}
