Watcher

All Known Subinterfaces:

WatcherEx, WatcherUpdatable
```
public interface Watcher
```
Watcher is the interface for Casbin watchers.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`setUpdateCallback(java.lang.Runnable runnable)`	SetUpdateCallback sets the callback function that the watcher will call when the policy in DB has been changed by other instances.
`void`	`setUpdateCallback(java.util.function.Consumer<java.lang.String> func)`	SetUpdateCallback sets the callback function that the watcher will call when the policy in DB has been changed by other instances.
`void`	`update()`	Update calls the update callback of other instances to synchronize their policy.

- Method Detail
  - setUpdateCallback
```
void setUpdateCallback(java.lang.Runnable runnable)
```
    SetUpdateCallback sets the callback function that the watcher will call when the policy in DB has been changed by other instances. A classic callback is Enforcer.loadPolicy().
    
    Parameters:
    
    runnable - the callback function, will be called when policy is updated.
  - setUpdateCallback
```
void setUpdateCallback(java.util.function.Consumer<java.lang.String> func)
```
    SetUpdateCallback sets the callback function that the watcher will call when the policy in DB has been changed by other instances. A classic callback is Enforcer.loadPolicy().
    
    Parameters:
    
    func - the callback function, will be called when policy is updated.
  - update
```
void update()
```
    Update calls the update callback of other instances to synchronize their policy. It is usually called after changing the policy in DB, like Enforcer.savePolicy(), Enforcer.addPolicy(), Enforcer.removePolicy(), etc.