It is called APPC, this tool calls underneath to jspc and ejbc to achieve this task.
http://docs.oracle.com/cd/E17904_01/web.1111/e13719/appc_ejbc.htm#EJBPG1088
After calling setDomainEnv.sh (.cmd) we can execute directly: weblogic.appc [files]
Also, we can compile only JSPs files with: weblogic.jspc [files]
http://docs.oracle.com/cd/E17904_01/web.1111/e13712/reference.htm#i57791
It is recommended to use it at development time as well, so we can hit compilation errors before the first request on the web container.
It exists the Ant task as well: wlapcc
Sample:
java weblogic.jspc -forceGeneration -keepgenerated -verboseJspc -d d:\tmp\export\ -classpath .;D:\proj\webapp-wl-v4\web\WEB-INF\classes;D:\proj\webapp-wl-v4\foo.jar;D:\proj\webapp-wl-v4\lib\bar.jar index.jsp