to.etc.dbutil

Class DbLockKeeper

java.lang.Object

to.etc.dbutil.DbLockKeeper

@ThreadSafe
public final class DbLockKeeper
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DbLockKeeper.LockHandle Handle for a specific lock.

Method Summary

Modifier and Type	Method and Description
static DbLockKeeper	getInstance()
static void	init(DataSource ds) Initializes the DbLockKeeper.
DbLockKeeper.LockHandle	lock(String lockName) Method should be used to create a lock.
DbLockKeeper.LockHandle	lockNowait(String lockName) Get a lock, but do not wait for it- if the lock is taken the code returns immediately, returning a null lock handle.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static DbLockKeeper getInstance()

init

public static void init(DataSource ds)

Initializes the DbLockKeeper. Creates the required tables and sets the datasource. Should be called before the first use of this class.

Parameters:

ds - the datasource used to create the connections.

lock

public DbLockKeeper.LockHandle lock(String lockName)
                             throws Exception

Method should be used to create a lock. It can be used to make sure that certain processes won't run at the same time on multiple servers. The method won't finish until lock is given. IMPORTANT The lock must be released after execution of the code.

Parameters:

lockName - the name of the lock

Throws:

Exception

lockNowait

@Nullable
public DbLockKeeper.LockHandle lockNowait(String lockName)
                                             throws Exception

Get a lock, but do not wait for it- if the lock is taken the code returns immediately, returning a null lock handle.

Parameters:

lockName -

Returns:

Throws:

Exception