exceptions of uri

You will feel unconfident when you met some troubles especially when you really want to learn sth.  the problem is still there even if you have spent lots of time and energy to try to solve it. and then you will gradually  learn to give it up. and finally, nothing you will get.

recently, i me the problem, when i am learning the Expression Language, in one of the examples, there is a sentence like this: <%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jst1/fmt" %>.
the browser will throw an exception:
org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application.
tell you a story, i dreamed that i have solved the  question last night, the main problem is that  my pc could not link to the network.   aha, it is crazy, maybe  ridiculous.

it is upset that when i found that was just a dream.
but,fortunately, i didn't give up, i decided to turn to others who know El clearly, aha, it is great and it works.
now the answer is to put the standard.jar on the apllication classpath WEB-INF/lib
hahah....................

althought you suffer a lot, i think, you will get sth equal to your pain.
really, once you find you  learn sth new, you will not feel the life is dull, in contrast, feeling of achievement.
so, go ahead...................