Programmatically get Tomcat HTTP Connector's maxPostSize in a JSP

问题

I am using Tomcat 6 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?

回答1:

Assuming that you've only one Tomcat service with one connector, then you can access it in Servlet by:

int maxPostSize = ServerFactory.getServer().findServices()[0].findConnectors()[0].getMaxPostSize();

ServerFactory is by the way org.apache.catlina.ServerFactory.

Note: this tight-couples your code to the Tomcat servletcontainer and your webapp may not be reuseable on other servletcontainers, possibly even not different versions. Consider configuring your own context parameter in web.xml with the same value.

<context-param>
    <param-name>maxPostSize</param-name>
    <param-value>2097152</param-value>
</context-param>

Then you can access it in Servlet by

int maxPostSize = Integer.valueOf(getServletContext().getInitParameter("maxPostSize"));

or in JSP by

${initParam.maxPostSize}

回答2:

In Tomcat7 the ServerFactory class is gone. Apparently one should be able to obtain the Server reference using

org.apache.tomee.loader.TomcatHelper.getServer()

...which resides in org.apache.openejb:tomee-loader.

来源：https://stackoverflow.com/questions/3894413/programmatically-get-tomcat-http-connectors-maxpostsize-in-a-jsp