Oracle DB: Listener refused the connection with the following error: ORA-12519, TNS:no appropriate service handler found in Oracle database

The above error  can be caused by low "processes" values,  The current process value in the Oracle Database can be identified by following query,

select * from v$resource_limit where resource_name = 'processes'; 

RESOURCE_NAME CURRENT_UTILIZATION MAX_UTILIZATION LIMIT_VALUE 

------------- ------------------- --------------- ----------- 

processes           148           150               150   

Resolution:  Increase the number of processes in the Oracle spfile, refer the following link,
https://community.oracle.com/thread/2471899?tstart=0
Increase the no. of processes by issuing the following command, before that shutdown mysql server, and Tomcat Server.
cmd>sqlplus / as sysdba
sqlplus>alter system set processes=300 scope=spfile;
sqlplus>shut immediate;
sqlplus>startup

By setting the high Processes value, we can avoid TNS Connection Handler issue in OracleXE