java.sql.SQLException: ORA-01000: maximum open cursors exceeded

Could you run the sql command to determine the number of open_cursors set by default:
show PARAMETER cursors;

If the value for open_cursors is 300, please run this following sql command to set it to a higher value:
ALTER SYSTEM SET open_cursors =800;

Run this sql command again to see if the change was made:
show PARAMETER cursors;