| Class | Description | 
|---|---|
| DefaultMessageSecurityExpressionHandler<T> | 
 The default implementation of  
SecurityExpressionHandler which uses a
 MessageSecurityExpressionRoot. | 
| ExpressionBasedMessageSecurityMetadataSourceFactory | 
 A class used to create a  
MessageSecurityMetadataSource that uses
 MessageMatcher mapped to Spring Expressions. | 
| MessageExpressionVoter<T> | 
 Voter which handles  
Message authorisation decisions. | 
| MessageSecurityExpressionRoot | 
 The  
SecurityExpressionRoot used for Message expressions. |