<choose>
<when test="">
...
</when>
<otherwise>
...
</otherwise>
</choose>
choose为一个整体,类似于switch;
when相当于if,otherwise相当于else
<choose>
<when test="">
...
</when>
<otherwise>
...
</otherwise>
</choose>
choose为一个整体,类似于switch;
when相当于if,otherwise相当于else