Domino synchronization. How to convert Lotusscript functions like CodeLock to Java?

Question

This class for syncronization in Lotusscript, create Lock for document by document ID. Implement functional: only one agent can simultaneously change document or documents under the lockID to database.

Class classSynchronization
    
    Private lockName As String
    Private lockID As Integer

    Function getCount As long
        getCount = CodeLockCheck(Me.lockID)
    End Function
    
    Function Wait As Boolean
        Wait = CodeLock(Me.lockID) 
    End Function
    
    Sub New( lockNameID As String)
        
        Me.lockName = lockNameID
        Me.lockID = CreateLock(Me.lockName)

    '   MsgBox "Synchronization Lock: "+ Me.lockName+ " Count in queue: " + CStr (CodeLockCheck(Me.lockID)  )

    End Sub
    
    Sub Delete()
    
        Dim releaseLock As Boolean
        Dim deleteLock As Boolean
    
        '   MsgBox "Synchronization Release Lock: "+ Me.lockName+ " Count in queue: " + CStr (CodeLockCheck(Me.lockID)  )
        
        ' When we are finished, destroy this reference  to the lock
        releaseLock = CodeUnlock(Me.lockID)
        deleteLock = DestroyLock(Me.lockID) 
    
    End Sub 
    
End Class

How to convert this class to Java class in domino?

Answer 1

There are no direct Java equivalents to the builtin locking (CodeLock, CodeUnLock, DestroyLock, CreateLock, DestroyLock...) functions in LotusScript. You will need to learn about Java's synchronization primitives, analyze your application's synchronization requirements, and find the best fit to accomplish what your application requires.

Answer 2

1. Is the Java operation synchronized(obj) work between NotesSession? (In other words, 2 users run one agent at the same time and try to set changes in a document). where obj is a string and has the value NoteID.
2. How to create the obj available between NotesSession?

No Effect

    import lotus.domino.*;
    import java.util.*;

public class JavaAgent extends AgentBase {

    public void NotesMain() {


        try {
            Session session = getSession();
            AgentContext agentContext = session.getAgentContext();
            Document doc = agentContext.getDocumentContext();

            String lock = doc.getNoteID();

            synchronized (lock) {

                for (int i = 1; i < 10; i++){
                    System.out.println(lock + " " + session.getEffectiveUserName() + " " + Integer.toString(i));
                    Thread.sleep(1000);
                }
            }

        } catch(Exception e) {
            e.printStackTrace();
        }
    }
}

Result:

[002413:000171-00007F99DC253700] 12/03/2021 11:47:51 PM  HTTP JVM: 46AFE CN=Administrator/O=test 1
[002413:000171-00007F99DC253700] 12/03/2021 11:47:52 PM  HTTP JVM: 46AFE CN=Administrator/O=test 2
[002413:000171-00007F99DC253700] 12/03/2021 11:47:53 PM  HTTP JVM: 46AFE CN=Administrator/O=test 3
[002413:000173-00007F99DC4C7700] 12/03/2021 11:47:54 PM  HTTP JVM: 46AFE CN=User 3/O=test 1
[002413:000171-00007F99DC253700] 12/03/2021 11:47:54 PM  HTTP JVM: 46AFE CN=Administrator/O=test 4
[002413:000173-00007F99DC4C7700] 12/03/2021 11:47:55 PM  HTTP JVM: 46AFE CN=User 3/O=test 2
[002413:000171-00007F99DC253700] 12/03/2021 11:47:55 PM  HTTP JVM: 46AFE CN=Administrator/O=test 5
[002413:000173-00007F99DC4C7700] 12/03/2021 11:47:56 PM  HTTP JVM: 46AFE CN=User 3/O=test 3
[002413:000171-00007F99DC253700] 12/03/2021 11:47:56 PM  HTTP JVM: 46AFE CN=Administrator/O=test 6
[002413:000173-00007F99DC4C7700] 12/03/2021 11:47:57 PM  HTTP JVM: 46AFE CN=User 3/O=test 4
[002413:000171-00007F99DC253700] 12/03/2021 11:47:57 PM  HTTP JVM: 46AFE CN=Administrator/O=test 7
[002413:000173-00007F99DC4C7700] 12/03/2021 11:47:58 PM  HTTP JVM: 46AFE CN=User 3/O=test 5
[002413:000171-00007F99DC253700] 12/03/2021 11:47:58 PM  HTTP JVM: 46AFE CN=Administrator/O=test 8
[002413:000173-00007F99DC4C7700] 12/03/2021 11:47:59 PM  HTTP JVM: 46AFE CN=User 3/O=test 6
[002413:000171-00007F99DC253700] 12/03/2021 11:47:59 PM  HTTP JVM: 46AFE CN=Administrator/O=test 9
[002413:000173-00007F99DC4C7700] 12/03/2021 11:48:00 PM  HTTP JVM: 46AFE CN=User 3/O=test 7
[002413:000173-00007F99DC4C7700] 12/03/2021 11:48:01 PM  HTTP JVM: 46AFE CN=User 3/O=test 8
[002413:000173-00007F99DC4C7700] 12/03/2021 11:48:02 PM  HTTP JVM: 46AFE CN=User 3/O=test 9