java.lang.Object
- com.aoapps.appcluster.ResourceSynchronizer<R,RN>
- - com.aoapps.appcluster.CronResourceSynchronizer<R,RN>

```
public abstract class CronResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
extends ResourceSynchronizer<R,RN>
```
Synchronizes resource based on cron-like schedules. If the local node is stopped, the synchronizer is stopped. If the locale node or the remote node is disabled, the synchronized is disabled. Otherwise, the synchronizer will operate on a cron-like scheduled basis for testing and synchronizing.

To support masters synchronizing while slaves only test, if a test and a synchronization are scheduled at the same moment, the synchronization is performed if possible, and the test is only performed if the synchronization is not possible. Thus, a synchronization also counts as a test and should perform at least as thorough of a check as a test would perform.

If a synchronization or test is missed, no catch-up is performed. This is true for both when the node is down or when a previous test/synchronization took too long, overlapping the current schedule.

Author:

AO Industries, Inc.

Field Summary
- Fields inherited from class com.aoapps.appcluster.ResourceSynchronizer
  localResourceNode, remoteResourceNode

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`CronResourceSynchronizer(RN localResourceNode, RN remoteResourceNode, Schedule synchronizeSchedule, Schedule testSchedule)`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected abstract boolean`	`canSynchronize(ResourceSynchronizationMode mode, ResourceNodeDnsResult localDnsResult, ResourceNodeDnsResult remoteDnsResult)`	Checks if a resource may be synchronized given the current DNS state of the nodes.
`boolean`	`canSynchronizeNow(ResourceSynchronizationMode mode)`	Determines if the synchronizer can run now.
`boolean`	`getCanSynchronizeNow()`	Convenience method for JavaBeans property.
`boolean`	`getCanTestNow()`	Convenience method for JavaBeans property.
`ResourceSynchronizationResult`	`getLastResult()`	Gets the last synchronization result or `null` if unavailable.
`ResourceSynchronizerState`	`getState()`	Gets the current synchronization state.
`String`	`getStateMessage()`	Gets a description of the current state or `null` for no specific message.
`Schedule`	`getSynchronizeSchedule()`	Gets the synchronize schedule.
`Schedule`	`getTestSchedule()`	Gets the test schedule.
`protected void`	`start()`	Starts the synchronizer.
`protected void`	`stop()`	Stops the synchronizer.
`protected abstract ResourceSynchronizationResult`	`synchronize(ResourceSynchronizationMode mode, ResourceNodeDnsResult localDnsResult, ResourceNodeDnsResult remoteDnsResult)`	Synchronizes (or tests) the resource.
`void`	`synchronizeNow(ResourceSynchronizationMode mode)`	Schedules an immediate synchronization if the resource is enabled and sleeping.

Methods inherited from class com.aoapps.appcluster.ResourceSynchronizer
getLocalResourceNode, getRemoteResourceNode, getResultStatus, toString

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

- Constructor Detail
  - CronResourceSynchronizer
```
protected CronResourceSynchronizer(RN localResourceNode,
                                   RN remoteResourceNode,
                                   Schedule synchronizeSchedule,
                                   Schedule testSchedule)
```
- Method Detail
  - getSynchronizeSchedule
```
public Schedule getSynchronizeSchedule()
```
    Gets the synchronize schedule.
  - canSynchronizeNow
```
public boolean canSynchronizeNow(ResourceSynchronizationMode mode)
```
    Determines if the synchronizer can run now.
  - getCanSynchronizeNow
```
public boolean getCanSynchronizeNow()
```
    Convenience method for JavaBeans property.
    
    See Also:
    
    canSynchronizeNow(com.aoapps.appcluster.ResourceSynchronizationMode), ResourceSynchronizationMode.SYNCHRONIZE
  - getCanTestNow
```
public boolean getCanTestNow()
```
    Convenience method for JavaBeans property.
    
    See Also:
    
    canSynchronizeNow(com.aoapps.appcluster.ResourceSynchronizationMode), ResourceSynchronizationMode.TEST_ONLY
  - synchronizeNow
```
public void synchronizeNow(ResourceSynchronizationMode mode)
```
    Schedules an immediate synchronization if the resource is enabled and sleeping.
    
    Specified by:
    
    synchronizeNow in class ResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
  - getTestSchedule
```
public Schedule getTestSchedule()
```
    Gets the test schedule.
  - getState
```
public ResourceSynchronizerState getState()
```
    Description copied from class: ResourceSynchronizer
    
    Gets the current synchronization state.
    
    Specified by:
    
    getState in class ResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
  - getStateMessage
```
public String getStateMessage()
```
    Description copied from class: ResourceSynchronizer
    
    Gets a description of the current state or null for no specific message.
    
    Specified by:
    
    getStateMessage in class ResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
  - getLastResult
```
public ResourceSynchronizationResult getLastResult()
```
    Description copied from class: ResourceSynchronizer
    
    Gets the last synchronization result or null if unavailable.
    
    Specified by:
    
    getLastResult in class ResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
  - start
```
protected void start()
```
    Description copied from class: ResourceSynchronizer
    
    Starts the synchronizer.
    
    Specified by:
    
    start in class ResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
  - stop
```
protected void stop()
```
    Description copied from class: ResourceSynchronizer
    
    Stops the synchronizer.
    
    Specified by:
    
    stop in class ResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>
  - canSynchronize
```
protected abstract boolean canSynchronize(ResourceSynchronizationMode mode,
                                          ResourceNodeDnsResult localDnsResult,
                                          ResourceNodeDnsResult remoteDnsResult)
```
    Checks if a resource may be synchronized given the current DNS state of the nodes.
  - synchronize
```
protected abstract ResourceSynchronizationResult synchronize(ResourceSynchronizationMode mode,
                                                             ResourceNodeDnsResult localDnsResult,
                                                             ResourceNodeDnsResult remoteDnsResult)
```
    Synchronizes (or tests) the resource.

Class CronResourceSynchronizer<R extends CronResource<R,​RN>,​RN extends CronResourceNode<R,​RN>>

Field Summary

Fields inherited from class com.aoapps.appcluster.ResourceSynchronizer

Constructor Summary

Method Summary

Methods inherited from class com.aoapps.appcluster.ResourceSynchronizer

Methods inherited from class java.lang.Object

Constructor Detail

CronResourceSynchronizer

Method Detail

getSynchronizeSchedule

canSynchronizeNow

getCanSynchronizeNow

getCanTestNow

synchronizeNow

getTestSchedule

getState

getStateMessage

getLastResult

start

stop

canSynchronize

synchronize

Class CronResourceSynchronizer<R extends CronResource<R,RN>,RN extends CronResourceNode<R,RN>>