How to fix JSP compiler warning: one JAR was scann

Question

When starting the application or compiling JSP via ant, Tomcat 7 Jasper complains about superfluous or misplaced JAR file. I got below message

**compile-jsp:**
   [jasper] Jul 31, 2012 7:15:15 PM org.apache.jasper.compiler.TldLocationsCache tldScanJar
   [jasper] INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time. 

how to Skipping unneeded JARs during scanning can improve startup time and JSP compilation time in tomcat?

how to enable better output?

Answer 1

Uncomment this line (in /conf/logging.properties)

org.apache.jasper.compiler.TldLocationsCache.level = FINE

Work's for me in tomcat 7.0.53!

Answer 2

For Tomcat 8, I had to add the following line to tomcat/conf/logging.properties for the jars scanned by Tomcat to show up in the logs:

org.apache.jasper.servlet.TldScanner.level = FINE

Answer 3

Tomcat 8.5. Inside catalina.properties, located in the /conf directory set:

tomcat.util.scan.StandardJarScanFilter.jarsToSkip=\*.jar

Or go into context.xml, located in Tomcat's /conf directory and add:

<JarScanner scanClassPath="false"/>

Answer 4

For Tomcat 8, I had to add the following line to catalina.properties for preventing jars scanned by Tomcat:

tomcat.util.scan.StandardJarScanFilter.jarsToSkip=jsp-api.jar,servlet-api.jar