what does the attribute
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/poll">
<Resource name="jdbc/PollDatasource" auth="Container" type="javax.sql.DataSource"
// etc etc
"antiJARLocking - If true, the Tomcat classloader will take extra measures to avoid JAR file locking when resources are accessed inside JARs through URLs. This will impact startup time of applications, but could prove to be useful on platforms or configurations where file locking can occur. If not specified, the default value is false."
(The problem they are trying to address … I think … is that a locked JAR file will stop things like hot redeployment from working.)
Read the documentation for more information.
antiJARLocking attribute is gone in Tomcat 8. See the