ExchangeAttribute (Undertow Core 2.3.20.Final API)

All Known Implementing Classes:

AuthenticationTypeExchangeAttribute, BytesSentAttribute, CompositeExchangeAttribute, ConstantExchangeAttribute, CookieAttribute, DateTimeAttribute, HostAndPortAttribute, IdentUsernameAttribute, LocalIPAttribute, LocalPortAttribute, LocalServerNameAttribute, NullAttribute, PathParameterAttribute, PredicateContextAttribute, QueryParameterAttribute, QueryStringAttribute, QuotingExchangeAttribute, RelativePathAttribute, RemoteHostAttribute, RemoteIPAttribute, RemoteObfuscatedIPAttribute, RemoteUserAttribute, RequestCookieAttribute, RequestHeaderAttribute, RequestLineAttribute, RequestMethodAttribute, RequestPathAttribute, RequestProtocolAttribute, RequestSchemeAttribute, RequestURLAttribute, ResolvedPathAttribute, ResponseCodeAttribute, ResponseCookieAttribute, ResponseHeaderAttribute, ResponseReasonPhraseAttribute, ResponseTimeAttribute, SecureExchangeAttribute, SslCipherAttribute, SslClientCertAttribute, SslSessionIdAttribute, StoredResponse, SubstituteEmptyWrapper.SubstituteEmptyAttribute, ThreadNameAttribute, TransportProtocolAttribute
```
public interface ExchangeAttribute
```
Representation of a string attribute from a HTTP server exchange.

Author:

Stuart Douglas

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`String`	`readAttribute(HttpServerExchange exchange)`	Resolve the attribute from the HTTP server exchange.
`void`	`writeAttribute(HttpServerExchange exchange, String newValue)`	Sets a new value for the attribute.

- Method Detail
  - readAttribute
```
String readAttribute(HttpServerExchange exchange)
```
    Resolve the attribute from the HTTP server exchange. This may return null if the attribute is not present.
    
    Parameters:
    
    exchange - The exchange
    
    Returns:
    
    The attribute
  - writeAttribute
```
void writeAttribute(HttpServerExchange exchange,
                    String newValue)
             throws ReadOnlyAttributeException
```
    Sets a new value for the attribute. Not all attributes are writable.
    
    Parameters:
    
    exchange - The exchange
    
    newValue - The new value for the attribute
    
    Throws:
    
    ReadOnlyAttributeException - when attribute cannot be written