java.lang.Object
- com.zfabrik.work.WorkUnit

All Implemented Interfaces:

java.lang.AutoCloseable
```
public final class WorkUnit
extends java.lang.Object
implements java.lang.AutoCloseable
```
A Work Unit comprises resources that are bound to some logical work process. A work unit may be transactional or immediate. Resources are encouraged to register with the work unit. In order to orderly use the work unit mechanism, it is required to initialize and later close a work unit by using it as an AutoCloseable or explicitly:
```
 try (WorkUnit.initCurrent()) {
 ...
 }
 
```
or
```
 WorkUnit.initCurrent();
 try {
 ...
 } finally {
    WorkUnit.closeCurrent();
 }
 
```
This pattern is implemented by the work(Callable) method and its sibling. The application thread pool implementation uses this pattern, so that in general it is not necessary to implement it individually, except work has to be done in a Timer Thread and will not be associated with the Application Thread Pool (which is the preferred method!). See also IThreadPool.executeAs(Runnable, boolean). On the current thread however, after any completion, i.a. after a call to close() we release the work unit association. This is for resource consumption reasons (and not to hold on to something that should be collectable) but also so that we can normally see whether a thread has been setup correctly during getCurrent(). We want to know (by exception) if a thread is querying for a work unit although it has not been properly initialized - which in turn indicates that it will most likely not be completed properly either.
Author:

Henning

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`attach(WorkUnit unit)`	attaches a given work unit with the current thread.
`void`	`bindResource(java.lang.String key, IWorkResource resource)`	bind and, if unit is stateful, begin resource
`void`	`close()`	Close work unit.
`static void`	`closeCurrent()`	Closes the current work unit (if any).
`void`	`commit()`	Commit work unit.
`static void`	`commitCurrent()`	commits the current work unit (if any)
`static WorkUnit`	`detach()`	Detaches current work unit (if any) from the current thread
`static WorkUnit`	`getCurrent()`	gets current work unit.
`IWorkResource`	`getResource(java.lang.String key)`	returns a named work resource
`boolean`	`getRollbackOnly()`	Gets whether this unit is to be rolled back on close
`static boolean`	`getRollbackOnlyCurrent()`	Gets whether the current work unit, if any, is to be rolled back on close.
`static WorkUnit`	`initCurrent()`	initializes a work unit orderly on a thread join the current, if present.
`static WorkUnit`	`queryCurrent()`	queries current work unit but will not instantiate one.
`void`	`rollback()`	Rollback the work unit.
`static void`	`rollBackCurrent()`	rolls back the current work unit (if any)
`void`	`setRollbackOnly()`	Sets this unit to be rolled back on close.
`static void`	`setRollbackOnlyCurrent()`	Sets the current work unit, if any, to be rolled back on close.
`static <T,E extends java.lang.Exception> T`	`supply(ThrowingSupplier<T,E> supplier)`	Execute a `ThrowingSupplier` within a complete work unit, incl.
`IWorkResource`	`unbindResource(java.lang.String key)`	unbind and if unit stateful rolls back resource
`static void`	`work(java.lang.Runnable r)`	Execute a runnable within a complete work unit, incl.
`static <T> T`	`work(java.util.concurrent.Callable<T> r)`	Execute a `Callable` within a complete work unit, incl.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - queryCurrent
```
public static final WorkUnit queryCurrent()
```
    queries current work unit but will not instantiate one.
  - getCurrent
```
public static final WorkUnit getCurrent()
```
    gets current work unit. If none bound, throw an exception as this indicates that this is a thread that has not orderly initialized the work unit.
  - commitCurrent
```
public static void commitCurrent()
```
    commits the current work unit (if any)
  - rollBackCurrent
```
public static void rollBackCurrent()
```
    rolls back the current work unit (if any)
  - initCurrent
```
public static WorkUnit initCurrent()
```
    initializes a work unit orderly on a thread join the current, if present.
  - closeCurrent
```
public static void closeCurrent()
```
    Closes the current work unit (if any). See close().
  - setRollbackOnlyCurrent
```
public static void setRollbackOnlyCurrent()
```
    Sets the current work unit, if any, to be rolled back on close. See setRollbackOnly()
  - getRollbackOnlyCurrent
```
public static boolean getRollbackOnlyCurrent()
```
    Gets whether the current work unit, if any, is to be rolled back on close. See getRollbackOnly().
  - detach
```
public static WorkUnit detach()
```
    Detaches current work unit (if any) from the current thread
  - attach
```
public static void attach(WorkUnit unit)
```
    attaches a given work unit with the current thread. Will fail if there is one currently associated with the current thread.
  - commit
```
public void commit()
```
    Commit work unit. If the work unit is set for rollback only however, the work unit will be rolled back. In the case of a commit, all enlisted resources will first receive a IWorkResource.beforeCompletion(boolean). If during that phase the work unit is set to rollback only, a rollback is performed. See rollback(). Otherwise all resources receive a IWorkResource.commit() before all resources receive a IWorkResource.afterCompletion(boolean).
  - rollback
```
public void rollback()
```
    Rollback the work unit. For all enlisted resources a rollback and an after completion event will be triggered. See IWorkResource for more details.
  - setRollbackOnly
```
public void setRollbackOnly()
```
    Sets this unit to be rolled back on close. That is, instead of committing a close will rollback(), if set to true
  - getRollbackOnly
```
public boolean getRollbackOnly()
```
    Gets whether this unit is to be rolled back on close
  - close
```
public void close()
```
    Close work unit. Note that a call to initCurrent() is either opening a new work unit of joining an existing. In the latter case, a use counter is incremented. A call to close only performs the actual close action, when the use counter is 1. Otherwise the use counter will simply be decreased. The actual close action is rollback(), if the work unit was set to rollback only (via setRollbackOnly() or setRollbackOnlyCurrent()) or commit() otherwise. In both cases, all enlisted resources will receive a close event. See IWorkResource for more details. If this work unit is the current work unit, it will be detached and there will be no current work unit anymore.
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
  - bindResource
```
public void bindResource(java.lang.String key,
                         IWorkResource resource)
```
    bind and, if unit is stateful, begin resource
  - unbindResource
```
public IWorkResource unbindResource(java.lang.String key)
```
    unbind and if unit stateful rolls back resource
  - getResource
```
public IWorkResource getResource(java.lang.String key)
```
    returns a named work resource
  - work
```
public static void work(java.lang.Runnable r)
```
    Execute a runnable within a complete work unit, incl. initialization and close. If the execution of the runnable throws an exception, the work unit will be rolled back.
  - supply
```
public static <T,E extends java.lang.Exception> T supply(ThrowingSupplier<T,E> supplier)
                                                        throws E extends java.lang.Exception
```
    Execute a ThrowingSupplier within a complete work unit, incl. initialization and close. If the execution of the runnable throws an exception, the work unit will be rolled back.
    
    Throws:
    
    E extends java.lang.Exception
  - work
```
public static <T> T work(java.util.concurrent.Callable<T> r)
                  throws java.lang.Exception
```
    Execute a Callable within a complete work unit, incl. initialization and close. If the execution of the runnable throws an exception, the work unit will be rolled back.
    
    Throws:
    
    java.lang.Exception

Class WorkUnit

Method Summary

Methods inherited from class java.lang.Object

Method Detail

queryCurrent

getCurrent

commitCurrent

rollBackCurrent

initCurrent

closeCurrent

setRollbackOnlyCurrent

getRollbackOnlyCurrent

detach

attach

commit

rollback

setRollbackOnly

getRollbackOnly

close

bindResource

unbindResource

getResource

work

supply

work