切换工程的Libraries
选中工程,右键,Build Path,Config Build Path,选中你当前的Libraries,
点Romove,点Add Librarie,选Myeclipse Libraries,Next,J2EE6 Libraries,Finish
Never frown, even when you are sad, because you never know who is falling in love with your smile.
纵然伤心,也不要愁眉不展,因为你不知道谁会爱上你的笑容。