Getting a list of active sessions in Tomcat using Java

Question

I am developing a project in Java in which I want the count of all active sessions in Tomcat. Based on that I want to see how much of those users are active and actually usi

Answer 1

You can attach a jolokia jvm agent to the running tomcat and query the activeSessions attribute from the relevant MBeans via curl.

java -jar agent.jar start [TOMCAT-PID]
curl 'http://127.0.0.1:8778/jolokia/read/Catalina:context=*,host=*,type=Manager/activeSessions'
java -jar agent.jar stop [TOMCAT-PID]

This will give you something like

{  
   "request":{  
      "mbean":"Catalina:context=*,host=*,type=Manager",
      "attribute":"activeSessions",
      "type":"read"
   },
   "value":{  
      "Catalina:context=\/SampleApp,host=localhost,type=Manager":{  
         "activeSessions":1
      }
   },
   "timestamp":1553105659,
   "status":200
}