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Automatic Compilation  RSS feed

 
Sanath Ramesh kumar
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When i make some changes to the java content of my jsp (i.e,scriptlet), why do these changes reflect directly eventhough a JSP internally converts to a servlet??where as when changes are made to servlet they must be compiled manually to reflect the changes that have been made?
 
Guy deLyonesse
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Because a .jsp is not converted to a servlet internally in the way you might think. A .jsp page is compiled on the fly the first time it's requested, and relies on an actual servlet to be able to run. A true servlet is already compiled when it's installed.
 
Bear Bibeault
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That doesn't really answer the question.

After the changed JSP is translated into a servlet, that servlet is compiled and the resulting class is re-loaded, replacing the previously loaded class for that JSP's servlet. The reason that this is possible is because the containers use a special class-loader for re-loadng the JSP-generated servlet classes. Regular servlets use a "normal" class loader that doesn't reload classes on-the-fly.
 
Sanath Ramesh kumar
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@Bear Bibeault

According to you, every time I make changes to a .jsp file ,it would convert to a servlet.r8??Can i take this as granted??
 
Bear Bibeault
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Sanath Ramesh kumar wrote:every time I make changes to a .jsp file ,it would convert to a servlet.r8?

I don't know what a servlet.r8 is.

Every time the container detects that the JSP has been updated it will go through the translation an compilation process. See this article.
 
It is sorta covered in the JavaRanch Style Guide.
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