====== SpEL ======
  * [[http://docs.spring.io/spring/docs/current/spring-framework-reference/html/expressions.html|SpEL]]
  * [[https://dzone.com/articles/learn-spring-expression-language-with-examples|Learning the Spring Expression Language (SpEL) - DZone Java]]

===== 상수 사용하기 =====
<code>
#{T(fully.qualified.ClassName).CONSTANT}
</code>
===== Operators =====
  * Safe Navigation Operator
    * ''user?.address?.postcode'' 형태로 사용할 경우 user와 address가 null이라도 오류가 발생하지 않게 된다.
    * [[http://entireboy.egloos.com/4648216|[Spring] Safe navigation operator(?.) in SpEL(Spring Expression Language)]]
  * Elvis Operator
    * 지정된 값이 없을 경우 default 값 사용
    * ''@Value("#{myPorperties['my.file.key']?:'/my/default/file/path'}")'' 여기서 ''my.file.key''값이 없으면 기본으로 뒤에 나온 ''/my/defalt/file/path'' 사용
    * [[http://entireboy.egloos.com/4648215|[Spring] Elvis operator(?:) in SpEL(Spring Expression Language)]]