Programmatically get Tomcat8 HTTP Connector's maxPostSize in a JSP

Question

I am using Tomcat 8 and would like to be able to retrieve the maxPostSize (defined in the HTTP Connector in server.xml) programmatically from within a JSP so that I can know what the max file upload size is.

Is there a way to get this?

Answer 1

You can use JMX to access the Connector MBeans locally and retrieve the value you need. You will need to know the port your Tomcat is running on.

An example:

private static int getMaxPostSize(int httpPort) throws Exception {
    MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();
    ObjectName objectName = new ObjectName("Catalina:type=Connector,port=" + httpPort);
    return (int) mbeanServer.getAttribute(objectName, "maxPostSize");
}