org.apache.mina.core.session

Interface IoSessionAttributeMap

public interface IoSessionAttributeMap

Stores the user-defined attributes which is provided per IoSession. All user-defined attribute accesses in IoSession are forwarded to the instance of IoSessionAttributeMap.

Author:

Apache MINA Project

Method Summary

Modifier and Type	Method and Description
boolean	containsAttribute(IoSession session, Object key)
void	dispose(IoSession session) Disposes any releases associated with the specified session.
Object	getAttribute(IoSession session, Object key, Object defaultValue)
Set<Object>	getAttributeKeys(IoSession session)
Object	removeAttribute(IoSession session, Object key) Removes a user-defined attribute with the specified key.
boolean	removeAttribute(IoSession session, Object key, Object value) Removes a user defined attribute with the specified key if the current attribute value is equal to the specified value.
boolean	replaceAttribute(IoSession session, Object key, Object oldValue, Object newValue) Replaces a user defined attribute with the specified key if the value of the attribute is equals to the specified old value.
Object	setAttribute(IoSession session, Object key, Object value) Sets a user-defined attribute.
Object	setAttributeIfAbsent(IoSession session, Object key, Object value) Sets a user defined attribute if the attribute with the specified key is not set yet.

Method Detail

getAttribute

Object getAttribute(IoSession session,
                    Object key,
                    Object defaultValue)

Parameters:

session - the session for which we want to get an attribute

key - The key we are looking for

defaultValue - The default returned value if the attribute is not found

Returns:

the value of user defined attribute associated with the specified key. If there's no such attribute, the specified default value is associated with the specified key, and the default value is returned. This method is same with the following code except that the operation is performed atomically.

 if (containsAttribute(key)) {
     return getAttribute(key);
 } else {
     setAttribute(key, defaultValue);
     return defaultValue;
 }
 

setAttribute

Object setAttribute(IoSession session,
                    Object key,
                    Object value)

Sets a user-defined attribute.

Parameters:

session - the session for which we want to set an attribute

key - the key of the attribute

value - the value of the attribute

Returns:

The old value of the attribute. null if it is new.

setAttributeIfAbsent

Object setAttributeIfAbsent(IoSession session,
                            Object key,
                            Object value)

Sets a user defined attribute if the attribute with the specified key is not set yet. This method is same with the following code except that the operation is performed atomically.

 if (containsAttribute(key)) {
     return getAttribute(key);
 } else {
     return setAttribute(key, value);
 }
 

Parameters:

session - the session for which we want to set an attribute

key - The key we are looking for

value - The value to inject

Returns:

The previous attribute

removeAttribute

Object removeAttribute(IoSession session,
                       Object key)

Removes a user-defined attribute with the specified key.

Parameters:

session - the session for which we want to remove an attribute

key - The key we are looking for

Returns:

The old value of the attribute. null if not found.

removeAttribute

boolean removeAttribute(IoSession session,
                        Object key,
                        Object value)

Removes a user defined attribute with the specified key if the current attribute value is equal to the specified value. This method is same with the following code except that the operation is performed atomically.

 if (containsAttribute(key) && getAttribute(key).equals(value)) {
     removeAttribute(key);
     return true;
 } else {
     return false;
 }
 

Parameters:

session - the session for which we want to remove a value

key - The key we are looking for

value - The value to remove

Returns:

true if the value has been removed, false if the key was not found of the value not removed

replaceAttribute

boolean replaceAttribute(IoSession session,
                         Object key,
                         Object oldValue,
                         Object newValue)

Replaces a user defined attribute with the specified key if the value of the attribute is equals to the specified old value. This method is same with the following code except that the operation is performed atomically.

 if (containsAttribute(key) && getAttribute(key).equals(oldValue)) {
     setAttribute(key, newValue);
     return true;
 } else {
     return false;
 }
 

Parameters:

session - the session for which we want to replace an attribute

key - The key we are looking for

oldValue - The old value to replace

newValue - The new value to set

Returns:

true if the value has been replaced, false if the key was not found of the value not replaced

containsAttribute

boolean containsAttribute(IoSession session,
                          Object key)

Parameters:

session - the session for which wa want to check if an attribute is present

key - The key we are looking for

Returns:

true if this session contains the attribute with the specified key.

getAttributeKeys

Set<Object> getAttributeKeys(IoSession session)

Parameters:

session - the session for which we want the set of attributes

Returns:

the set of keys of all user-defined attributes.

dispose

void dispose(IoSession session)
      throws Exception

Disposes any releases associated with the specified session. This method is invoked on disconnection.

Parameters:

session - the session to be disposed

Throws:

Exception - If the session can't be disposed