The Supreme Court on Monday adopted its first code of ethics, in the face of sustained criticism over undisclosed trips and gifts from wealthy benefactors to some justices, but the code lacks a means of enforcement. The policy, agreed to by all nine justices, does not appear to impose any significant new requirements and leaves compliance entirely to each justice. Indeed, the justices said they have long adhered to ethics standards and suggested that criticism of the court over ethics was the product of misunderstanding, rather than any missteps by the justices.