Best database for JSP?

Hello
I am new in Java
I want to know which database it the best for JSP?
for example php+MySQL is very good.
now I am using Xammp +Tomcat + JDK

You can use any database for Java. Try using all and see the differences.

I like to use oracle but I don't know it is free or no?

Yeah you can use it and download it freely. But remember, it's not free for commercial usage.

Can you give me download link?(I am windows user 7)

I don't know why many people don't use google. Oracle Database Software Downloads