If you are using Spring, you have this enum org.springframework.web.bind.annotation.RequestMethod
public enum RequestMethod {
GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS, TRACE;
}
EDIT : Here is the complete list of constants values in Java 6 You can see that some of those are available in the class HttpMethod but it contains less values than RequestMethod.
public @interface HttpMethod {
java.lang.String GET = "GET";
java.lang.String POST = "POST";
java.lang.String PUT = "PUT";
java.lang.String DELETE = "DELETE";
java.lang.String HEAD = "HEAD";
java.lang.String OPTIONS = "OPTIONS";
java.lang.String value();
}