Java tutorial
package org.springframework.security.oauth2.common.exceptions; /** * Exception thrown when a client was unable to authenticate. * * @author Ryan Heaton */ @SuppressWarnings("serial") public class UnauthorizedClientException extends ClientAuthenticationException { public UnauthorizedClientException(String msg, Throwable t) { super(msg, t); } public UnauthorizedClientException(String msg) { super(msg); } @Override public int getHttpErrorCode() { // The spec says this can be unauthorized return 401; } @Override public String getOAuth2ErrorCode() { return "unauthorized_client"; } }