ORA-12519: Solved

You are reading this post because you have come across  this error : ORA-12519, TNS:no appropriate service handler found.
 This problem is often due to the maximum number of  processes being exceeded. 
 In my case I had an excel file of around 1500 records that I wanted to read and insert into oracle using JDBC. 
Check your processes statistics:

show parameter processes;

        you may also run the followings for additional informations.

select count(*) from v$session;
select count(*) from v$process;
select * from v$resource_limit where resource_name='processes';

 Now lets us increase the max number of processes  to say 300;

alter system set processes=300 scope=spfile;

 Then shutdown now database

shutdown immediate;

Restart it

startup mount;

alter database archivelog;

alter database open;

Finally recheck

show paramter processes;

You may now run your program hopefully it will work.
This may not be the exact solution but at least, it is a way arounds.
Feel free to drop your comments;