posted 7 years ago
The first time a JSP is accessed, it is compiled into a class file and stored in a cache. The second time it is accessed, the application server checks to see if the JSP file has changed since the class file was created. If it has not changed, the compile step is skipped and the same class file is used. If you change the JSP, the application server will detect that it was changed since the last compile and will perform the compile step again and replace the class file in the cache.