Page History

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1. Wiki Markup
   \[#Q1 I am unable to compile my JSP!\]

2. Wiki Markup
   \[#Q2 I can't get servlets to work under /servlet/\*!\]

3. Wiki Markup
   \[#Q3 Why is the invoker evil?\]

4. Wiki Markup
   \[#Q4 How to I get Tomcat's version number?\]

5. Wiki Markup
   \[#Q5 Tomcat eats 100% of the CPU!\]

6. Wiki Markup
   \[#Q6 How do I get a customized error page?\]

7. Wiki Markup
   \[#Q7 Should I use the LE version?\]

8. Wiki Markup
   \[#Q8 How do I configure Tomcat to NOT to store the sessions during shutdown?\]

9. Wiki Markup
   \[#Q9 How do I disable tag pooling?\]

10. Wiki Markup
    \[#Q10 Is there a DTD for server.xml?\]

11. Wiki Markup
    \[#Q11 How do I change the welcome file? ( I want to show index.jsp instead of index.html)\]

12. Wiki Markup
    \[#Q12 How do I enable/disable directory listings?\]

13. Wiki Markup
    \[#Q13 How do I use symbolic links with jars?\]

14. Wiki Markup
    \[#Q14 How do I change the name of the file in the download Save-As dialog from a servlet? (or jsp)\]

15. Wiki Markup
    \[#Q15 Is tag pooling broken? It doesn't call release!\]

16. Wiki Markup
    \[#Q16 Why do I get java.lang.IllegalStateException ?\]

17. Wiki Markup
    \[#Q17 How do I make a scheduled event on Tomcat?\]

18. Wiki Markup
    \[#Q18 What is Element "web-app" does not allow "servlet" here?\]

19. Wiki Markup
    \[#Q19 How do open a file for reading in my webapp?\]

20. Wiki Markup
    \[#Q20 Can I run tomcat with the JRE, or do I need the full JDK?\]

21. Wiki Markup
    \[#Q21 Is tomcat an EJB server? Can I use EJBs with tomcat?\]

22. Wiki Markup
    \[#Q22 Can I access Tomcat's JNDI provider from outside tomcat?\]

23. Wiki Markup
    \[#Q23 Who uses tomcat in production?\]

24. Wiki Markup
    \[#Q24 I'm getting java.lang.ThreadDeath exceptions when reloading my webapp.\]

25. Wiki Markup
    \[#Q25 Help! Even though I run shutdown.sh (or shutdown.bat), Tomcat does not stop!\]

26. Wiki Markup
    \[#Q26 How do I debug JSP errors in the Admin web application?\]

27. Wiki Markup
    \[#Q27 What order do webapps start (or How can I change startup order)?\]

28. Wiki Markup
    \[#Q28 What's the different between a Valve and Filter? \\

Answers

I am unable to compile my JSP!

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There is no expected startup order. Neither the Servlet spec nor Tomcat define one. You can't rely on the apps starting in any particular order.

What's the different between a Valve and Filter?

A Filter lives in the webapp space and it's behavior is defined by the Servlet spec. It will work across all Servlet containers.

A Valve can do everything a Filter can do but is Tomcat specific, and potentially not portable across Tomcat versions. A Valve can be executed earlier in the lifecycle of a request, access Tomcat internals, and do other "interesting" decorations to your webapp in the chance you cannot change your deployed webapp.

If you can achieve the desired functionality with a Filter, it is the preferred way to go.