```
public interface SessionData
```
The data associated with the user session.
The session data can be obtained via the Session.getData() method.
Every item is stored with a SessionKey. A key is comprised of a type (as a Class) and an optional name. The combination of type and name identifies the value. Two keys with differing types but identical names are not considered to be equivalent.
When writing session data, the values are serialized immediately. That is, all objects are treated as immutable value objects from the perspective of this object. Any changes made to an object after it has been written to this object will NOT be persisted. If such changes are to be persisted, the object must be written again.
If a SessionSerializer is not provided for a given get/set, the getDefaultSerializer() will be used. The SessionModule provides a default implementation based on Java serialization. An alternative implementation can be used by overriding the Guice binding for SessionSerializer.
The session data is held in memory for a given request until the Session.save() method is called on the corresponding session. However, this object internally holds the data in serialized form. Therefore, every read and write incurs the cost of serialization and deserialization.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`clear()`	Remove all entries from the session data.
`default <T> Optional<T>`	`get(Class<T> type)`	Read the object with the given type, and no name, using the `default serializer`.
`default <T> Optional<T>`	`get(Class<T> type, SessionSerializer serializer)`	Read the object with the given type, and no name.
`default Optional<?>`	`get(String name)`	Read the object with the given name, using the `default serializer`.
`default Optional<?>`	`get(String name, SessionSerializer serializer)`	Read the object with the given name.
`default <T> Optional<T>`	`get(SessionKey<T> key)`	Fetch the object with the given key, using the `default serializer`.
`<T> Optional<T>`	`get(SessionKey<T> key, SessionSerializer serializer)`	Read the object with the given key.
`default SessionSerializer`	`getDefaultSerializer()`	See `Session.getDefaultSerializer()`.
`default JavaSessionSerializer`	`getJavaSerializer()`	See `Session.getJavaSerializer()`.
`Set<SessionKey<?>>`	`getKeys()`	The keys of all objects currently in the session.
`Session`	`getSession()`	The corresponding `Session` object.
`default boolean`	`isDirty()`	See `Session.isDirty()`.
`default void`	`remove(Class<?> type)`	Removes the object with the given type and no name, if it exists.
`default void`	`remove(String name)`	Removes the object with the name, if it exists.
`void`	`remove(SessionKey<?> key)`	Removes the object with the given key, if it exists.
`default <T> T`	`require(Class<T> type)`	Like `get(Class)`, but throws `NoSuchElementException` on the absence of a value.
`default <T> T`	`require(Class<T> type, SessionSerializer serializer)`	Like `get(Class, SessionSerializer)`, but throws `NoSuchElementException` on the absence of a value.
`default Object`	`require(String name)`	Like `get(String)`, but throws `NoSuchElementException` on the absence of a value.
`default Object`	`require(String name, SessionSerializer serializer)`	Like `get(String, SessionSerializer)`, but throws `NoSuchElementException` on the absence of a value.
`default <T> T`	`require(SessionKey<T> key)`	Like `get(SessionKey)`, but throws `NoSuchElementException` on the absence of a value.
`default <T> T`	`require(SessionKey<T> key, SessionSerializer serializer)`	Like `get(SessionKey, SessionSerializer)`, but throws `NoSuchElementException` on the absence of a value.
`default Operation`	`save()`	See `Session.save()`.
`default <T> void`	`set(Class<T> type, T value)`	Sets the value for the given type, using the `default serializer`.
`default <T> void`	`set(Class<T> type, T value, SessionSerializer serializer)`	Sets the value for the given type.
`default <T> void`	`set(String name, T value)`	Sets the value for the given name and type, using the runtime type of the value and the `default serializer`.
`default <T> void`	`set(String name, T value, SessionSerializer serializer)`	Sets the value for the given name and type, using the runtime type of the value.
`default <T> void`	`set(SessionKey<T> key, T value)`	Sets the value for the given key, using the `default serializer`.
`<T> void`	`set(SessionKey<T> key, T value, SessionSerializer serializer)`	Sets the value for the given key.
`default <T> void`	`set(T value)`	Sets the value for the type, using the runtime type of the value and the `default serializer`.
`default <T> void`	`set(T value, SessionSerializer serializer)`	Sets the value for the type, using the runtime type of the value.
`default Operation`	`terminate()`	See `Session.terminate()`.

- Method Detail
  - getKeys
```
Set<SessionKey<?>> getKeys()
```
    The keys of all objects currently in the session.
    
    Returns:
    
    the keys of all objects currently in the session
  - get
```
default <T> Optional<T> get(SessionKey<T> key)
                     throws Exception
```
    Fetch the object with the given key, using the default serializer.
    
    Type Parameters:
    
    T - the type of object
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
    
    See Also:
    
    require(SessionKey)
  - get
```
<T> Optional<T> get(SessionKey<T> key,
                    SessionSerializer serializer)
             throws Exception
```
    Read the object with the given key.
    
    Type Parameters:
    
    T - the type of object
    
    Parameters:
    
    key - the key
    
    serializer - the serializer
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
    
    See Also:
    
    require(SessionKey, SessionSerializer)
  - get
```
default Optional<?> get(String name)
                 throws Exception
```
    Read the object with the given name, using the default serializer.
    This method will throw an IllegalArgumentException if there is more than one object who's key has the given name.
    
    Parameters:
    
    name - the object name
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
    
    See Also:
    
    require(String)
  - get
```
default Optional<?> get(String name,
                        SessionSerializer serializer)
                 throws Exception
```
    Read the object with the given name.
    This method will throw an IllegalArgumentException if there is more than one object who's key has the given name.
    
    Parameters:
    
    name - the object name
    
    serializer - the serializer
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
    
    See Also:
    
    require(String, SessionSerializer)
  - get
```
default <T> Optional<T> get(Class<T> type)
                     throws Exception
```
    Read the object with the given type, and no name, using the default serializer.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    type - the type
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
    
    See Also:
    
    require(Class)
  - get
```
default <T> Optional<T> get(Class<T> type,
                            SessionSerializer serializer)
                     throws Exception
```
    Read the object with the given type, and no name.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    type - the type
    
    serializer - the serializer
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
    
    See Also:
    
    require(Class, SessionSerializer)
  - require
```
default <T> T require(SessionKey<T> key)
               throws Exception
```
    Like get(SessionKey), but throws NoSuchElementException on the absence of a value.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    key - the object key
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
  - require
```
default <T> T require(SessionKey<T> key,
                      SessionSerializer serializer)
               throws Exception
```
    Like get(SessionKey, SessionSerializer), but throws NoSuchElementException on the absence of a value.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    key - the object key
    
    serializer - the serializer
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
  - require
```
default <T> T require(Class<T> type)
               throws Exception
```
    Like get(Class), but throws NoSuchElementException on the absence of a value.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    type - the type
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
  - require
```
default <T> T require(Class<T> type,
                      SessionSerializer serializer)
               throws Exception
```
    Like get(Class, SessionSerializer), but throws NoSuchElementException on the absence of a value.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    type - the type
    
    serializer - the serializer
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
  - require
```
default Object require(String name)
                throws Exception
```
    Like get(String), but throws NoSuchElementException on the absence of a value.
    This method will throw an IllegalArgumentException if there is more than one object who's key has the given name.
    
    Parameters:
    
    name - the object name
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
  - require
```
default Object require(String name,
                       SessionSerializer serializer)
                throws Exception
```
    Like get(String, SessionSerializer), but throws NoSuchElementException on the absence of a value.
    This method will throw an IllegalArgumentException if there is more than one object who's key has the given name.
    
    Parameters:
    
    name - the object name
    
    serializer - the serializer
    
    Returns:
    
    the value for the given key
    
    Throws:
    
    Exception
  - set
```
default <T> void set(SessionKey<T> key,
                     T value)
              throws Exception
```
    Sets the value for the given key, using the default serializer.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    key - the key
    
    value - the value
    
    Throws:
    
    Exception
  - set
```
<T> void set(SessionKey<T> key,
             T value,
             SessionSerializer serializer)
      throws Exception
```
    Sets the value for the given key.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    key - the key
    
    value - the value
    
    serializer - the serializer
    
    Throws:
    
    Exception
  - set
```
default <T> void set(Class<T> type,
                     T value)
              throws Exception
```
    Sets the value for the given type, using the default serializer.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    type - the type
    
    value - the value
    
    Throws:
    
    Exception
  - set
```
default <T> void set(Class<T> type,
                     T value,
                     SessionSerializer serializer)
              throws Exception
```
    Sets the value for the given type.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    type - the type
    
    value - the value
    
    serializer - the serializer
    
    Throws:
    
    Exception
  - set
```
default <T> void set(String name,
                     T value)
              throws Exception
```
    Sets the value for the given name and type, using the runtime type of the value and the default serializer.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    name - the name
    
    value - the value
    
    Throws:
    
    Exception
  - set
```
default <T> void set(String name,
                     T value,
                     SessionSerializer serializer)
              throws Exception
```
    Sets the value for the given name and type, using the runtime type of the value.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    name - the name
    
    value - the value
    
    serializer - the serializer
    
    Throws:
    
    Exception
  - set
```
default <T> void set(T value)
              throws Exception
```
    Sets the value for the type, using the runtime type of the value and the default serializer.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    value - the value
    
    Throws:
    
    Exception
  - set
```
default <T> void set(T value,
                     SessionSerializer serializer)
              throws Exception
```
    Sets the value for the type, using the runtime type of the value.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    value - the value
    
    serializer - the serializer
    
    Throws:
    
    Exception
  - remove
```
void remove(SessionKey<?> key)
```
    Removes the object with the given key, if it exists.
    
    Parameters:
    
    key - the key
  - remove
```
default void remove(Class<?> type)
```
    Removes the object with the given type and no name, if it exists.
    
    Parameters:
    
    type - the type
  - remove
```
default void remove(String name)
```
    Removes the object with the name, if it exists.
    This method will throw a NoSuchElementException if there are more than one entries with the given name.
    
    Parameters:
    
    name - the name
  - clear
```
void clear()
```
    Remove all entries from the session data.
  - getSession
```
Session getSession()
```
    The corresponding Session object.
    
    Returns:
    
    the session object
  - isDirty
```
default boolean isDirty()
```
    See Session.isDirty().
    
    Returns:
    
    whether or not any changes have been made to the session data since it was accessed
  - save
```
default Operation save()
```
    See Session.save().
    
    Returns:
    
    the save operation
  - terminate
```
default Operation terminate()
```
    See Session.terminate().
    
    Returns:
    
    the terminate operation
  - getDefaultSerializer
```
default SessionSerializer getDefaultSerializer()
```
    See Session.getDefaultSerializer().
    
    Returns:
    
    the serializer to use by default
  - getJavaSerializer
```
default JavaSessionSerializer getJavaSerializer()
```
    See Session.getJavaSerializer().
    
    Returns:
    
    a serializer for Serializable objects

Interface SessionData

Method Summary

Method Detail

getKeys

get

get

get

get

get

get

require

require

require

require

require

require

set

set

set

set

set

set

set

set

remove

remove

remove

clear

getSession

isDirty

save

terminate

getDefaultSerializer

getJavaSerializer