Bean References

evaluation context가 bean resolver로 구성된 경우, @ symbol을 prefix로 사용하여 expression에서 bean을 조회할 수 있습니다. 다음 예제는 그 방법을 보여 줍니다:

1ExpressionParser parser = new SpelExpressionParser();
2StandardEvaluationContext context = new StandardEvaluationContext();
3context.setBeanResolver(new MyBeanResolver());
4
5// This will end up calling resolve(context, "someBean") on MyBeanResolver
6// during evaluation.
7Object bean = parser.parseExpression("@someBean").getValue(context);

1val parser = SpelExpressionParser()
2val context = StandardEvaluationContext()
3context.setBeanResolver(MyBeanResolver())
4
5// This will end up calling resolve(context, "someBean") on MyBeanResolver
6// during evaluation.
7val bean = parser.parseExpression("@someBean").getValue(context)

bean name에 dot (.)이나 다른 special character가 포함된 경우, bean의 name을 _string literal_로 제공해야 합니다. 예를 들어, @'order.service'와 같습니다.

factory bean 자체에 접근하려면, 대신 bean name 앞에 & symbol을 prefix로 붙여야 합니다. 다음 예제는 그 방법을 보여 줍니다:

1ExpressionParser parser = new SpelExpressionParser();
2StandardEvaluationContext context = new StandardEvaluationContext();
3context.setBeanResolver(new MyBeanResolver());
4
5// This will end up calling resolve(context, "&someFactoryBean") on
6// MyBeanResolver during evaluation.
7Object factoryBean = parser.parseExpression("&someFactoryBean").getValue(context);

1val parser = SpelExpressionParser()
2val context = StandardEvaluationContext()
3context.setBeanResolver(MyBeanResolver())
4
5// This will end up calling resolve(context, "&someFactoryBean") on
6// MyBeanResolver during evaluation.
7val factoryBean = parser.parseExpression("&someFactoryBean").getValue(context)