JSTL <c:set> body content exact specification

问题

can someone suggest how possible to interpret <c:set> body?

• <c:set var="movieList">One,Two,Three</c:set>

• <c:set var="movieList">"One","Two","Three"</c:set>

in the first case movieList is a string and in the second it is an array {"One", "Two", "Three"}

what is movieList in these examples:

• <c:set var="movieList">"On"e","Tw"o","Thr"ee"</c:set>

• <c:set var="movieList">"On\"e","Tw"o","Thr\"ee"</c:set>

回答1:

There's no difference in the interpreted Java type of the c:set's body. It are in all cases just String.

Even when you set a non-String type as c:set's body using EL such as

<c:set var="foo">${bean.someInteger}</c:set>

it'll be converted to String anyway by String#valueOf().

Only when you process the variable afterwards, there may be difference, depending on how you processed it. For example,

<c:set var="movieList">One,Two,Three</c:set>
<c:set var="realMovieArray" value="${fn:split(movieList, ',')}" />

will result ${realMovieArray} being a String[] with values of One, Two and Three.

回答2:

<c:set var="alphabet">A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z</c:set>

<c:forTokens items="${alphabet}" delims="," var="letter">
    ${letter}
</c:forTokens>

来源：https://stackoverflow.com/questions/6820666/jstl-cset-body-content-exact-specification