What was found
(CAN) AFTER GAINING ACCESS INSIDE THE COCKPIT, THE F/A COULDN`T REOPENED THE DOOR. AFTER MANY UNSUCCESSFUL ATTEMPTS TO UNLOCK/OPEN THE DOOR, F/A STAYED INSIDE THE COCKPIT FOR THE REMINDER OF THE FLIGHT. CABIN DUTIES WERE PERFORMED BY THE OTHER F/A. UPON ARRIVAL, MAINTENANCE OPENED THE DOOR. THE SPRING PIN ATTACHING THE LATCH BOLT TO THE SLIDE LATCH ASSY WAS FOUND BROKEN. THE PIN WAS REPLACED, THE DOOR TESTED AND THE ACFT RELEASE FOR SERVICE.