messaging/src/main/java/org/springframework/security/messaging/context/AuthenticationPrincipalArgumentResolver.java
public Object resolveArgument(MethodParameter parameter, Message<?> message)
			throws Exception {
		Authentication authentication = SecurityContextHolder.getContext()
				.getAuthentication();
		if (authentication == null) {
			return null;
		}
		Object principal = authentication.getPrincipal();

		AuthenticationPrincipal authPrincipal = findMethodAnnotation(
				AuthenticationPrincipal.class, parameter);

		String expressionToParse = authPrincipal.expression();
		if (StringUtils.hasLength(expressionToParse)) {
			StandardEvaluationContext context = new StandardEvaluationContext();
			context.setRootObject(principal);
			context.setVariable("this", principal);

			Expression expression = this.parser.parseExpression(expressionToParse);
			principal = expression.getValue(context);
		}

		if (principal != null
				&& !parameter.getParameterType().isAssignableFrom(principal.getClass())) {
			if (authPrincipal.errorOnInvalidType()) {
				throw new ClassCastException(principal + " is not assignable to "
						+ parameter.getParameterType());
			}
			else {
				return null;
			}
		}
		return principal;
	}
public Object resolveArgument(MethodParameter parameter, Message<?> message)
			throws Exception {
		Authentication authentication = SecurityContextHolder.getContext()
				.getAuthentication();
		if (authentication == null) {
			return null;
		}
		Object principal = authentication.getPrincipal();

		AuthenticationPrincipal authPrincipal = findMethodAnnotation(
				AuthenticationPrincipal.class, parameter);

		String expressionToParse = authPrincipal.expression();
		if (StringUtils.hasLength(expressionToParse)) {
			StandardEvaluationContext context = new StandardEvaluationContext();
			context.setRootObject(principal);
			context.setVariable("this", principal);

			Expression expression = this.parser.parseExpression(expressionToParse);
			principal = expression.getValue(context);
		}

		if (principal != null
				&& !parameter.getParameterType().isAssignableFrom(principal.getClass())) {
			if (authPrincipal.errorOnInvalidType()) {
				throw new ClassCastException(principal + " is not assignable to "
						+ parameter.getParameterType());
			}
			else {
				return null;
			}
		}
		return principal;
	}
public Object resolveArgument ( MethodParameter parameter , Message < ? > message ) throws Exception { Authentication authentication = SecurityContextHolder . getContext ( ) . getAuthentication ( ) ; if ( authentication == null ) { return null ; } Object principal = authentication . getPrincipal ( ) ; AuthenticationPrincipal authPrincipal = findMethodAnnotation ( AuthenticationPrincipal . class , parameter ) ; String expressionToParse = authPrincipal . expression ( ) ; if ( StringUtils . hasLength ( expressionToParse ) ) { StandardEvaluationContext context = new StandardEvaluationContext ( ) ; context . setRootObject ( principal ) ; context . setVariable ( "this" , principal ) ; Expression expression = this . parser . parseExpression ( expressionToParse ) ; principal = expression . getValue ( context ) ; } if ( principal != null && ! parameter . getParameterType ( ) . isAssignableFrom ( principal . getClass ( ) ) ) { if ( authPrincipal . errorOnInvalidType ( ) ) { throw new ClassCastException ( principal + " is not assignable to " + parameter . getParameterType ( ) ) ; } else { return null ; } } return principal ; }
/*
(non-Javadoc)

@see
org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver#
resolveArgument(org.springframework.core.MethodParameter,
org.springframework.messaging.Message)
/ * ( non - Javadoc )