PasswordProvider (Storm 2.7.1 API)

All Known Implementing Classes:

JassPasswordProvider, WorkerTokenAuthorizer
```
public interface PasswordProvider
```
A very basic API that will provide a password for a given user name. This is intended to be used with the SimpleSaslServerCallbackHandler to verify a user that is attempting to log in.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`Optional<char[]>`	`getPasswordFor(String user)`	Get an optional password for a user.
`default boolean`	`isImpersonationAllowed()`	Should impersonation be allowed by this password provider.
`default String`	`userName(String user)`	Convert the supplied user name to the actual user name that should be used in the system.

- Method Detail
  - getPasswordFor
```
Optional<char[]> getPasswordFor(String user)
```
    Get an optional password for a user. If no password for the user is found the option will be empty and another PasswordProvider would be tried.
    
    Parameters:
    
    user - the user this is for.
    
    Returns:
    
    the password if it is found.
  - isImpersonationAllowed
```
default boolean isImpersonationAllowed()
```
    Should impersonation be allowed by this password provider. The default is false.
    
    Returns:
    
    true if it should else false.
  - userName
```
default String userName(String user)
```
    Convert the supplied user name to the actual user name that should be used in the system. This may be called on any name. If it cannot be translated then a null may be returned or an exception thrown. If getPassword returns successfully this should not return null, nor throw an exception for the same user.
    
    Parameters:
    
    user - the SASL negotiated user name.
    
    Returns:
    
    the user name that storm should use.