title: how to configure log4j.xml to get the debug info of "javax.net.debug"
body: <p>I want to get the LDAP connect ssl handshake debug info ,so I set the system property "javax.net.debug" value "ssl,handshake" like this : </p>
  
  <p><code>System.property("javax.net.debug" , "ssl,handshake");</code>
  but I didn't get the ssl debug info.In my project,using log4j.xml to control the debug info, so I want to know how to configure log4j.xml to get the debug info of "javax.net.debug"? Thanks for your help!</p>