@Override
    public Set<AuthProvider> getAuthProviders()
    {
        final Set<AuthProvider> result = new LinkedHashSet<>();
        result.addAll( providersByPrefix.values() );
        result.add( fallbackProvider );

        return result;
    }
A {@link AuthProviderMapper} that can be used to draw some users from another source than the other users.

This implementation uses properties to define sets of usernames and a corresponding provider. When a user is not in
any set, a fallback provider is used.

Each set of usernames is defined by two properties. Use the following property to define the classname of an
{@link AuthProvider} to be used for this set: {@code propertyBasedAuthMapper.set.SET_NAME.provider.className}

Use the following property to identify a set of usernames: {@code propertyBasedAuthMapper.set.SET_NAME.members}. The
value for this property must be the name of another property, which is a listing of usernames (such a property is
likely re-used in a corresponding {@link org.jivesoftware.openfire.user.PropertyBasedUserProviderMapper}
configuration).

There is no upper bound on the amount of sets that can be configured.

Users that are not in any set will use the fallback provider. This provider is defined by its class name in the
property {@code propertyBasedAuthMapper.fallbackProvider.className}.

The following example defines two sets. Set "A" serves users john, jane and jack, and uses a DefaultAuthProvider.
Set "B" serves users dave and doris, and uses A JDBCAuthProvider. All other users are served by the fallback provider
that is a NativeAuthProvider.

<ul>
<li>{@code members.set.A = List( "john", "jane", "jack" )}</li>
<li>{@code members.set.B = List( "dave", "doris" )}</li>
<li>{@code propertyBasedAuthMapper.set.A.provider.className = org.jivesoftware.openfire.auth.DefaultAuthProvider}</li>
<li>{@code propertyBasedAuthMapper.set.A.members.propertyName = members.set.A}</li>
<li>{@code propertyBasedAuthMapper.set.B.provider.className = org.jivesoftware.openfire.auth.JDBCAuthProvider}</li>
<li>{@code propertyBasedAuthMapper.set.B.members.propertyName = members.set.B}</li>
<li>{@code propertyBasedAuthMapper.fallbackProvider.className = org.jivesoftware.openfire.auth.NativeAuthProvider}</li>
</ul>

@author Guus der Kinderen, guus@goodbytes.nl
xmppserver/src/main/java/org/jivesoftware/openfire/auth/PropertyBasedAuthProviderMapper.java