com.livis.livingtalks.ejb
Interface DataHandler

All Known Implementing Classes:

WriteThroughCache, CachingEntityHandler

public interface DataHandler

Method Summary

java.lang.Object	read(java.lang.String key) Read data stored at key.
java.lang.String	writeNew(java.lang.String key, java.lang.Object data) Write new data.
void	writeOld(java.lang.String key, java.lang.Object data) Updates old data.

Method Detail

writeNew

public java.lang.String writeNew(java.lang.String key,
                                 java.lang.Object data)
                          throws javax.ejb.CreateException

Write new data.

Parameters:

data - The data to be stored. data must not be null.

key - The key under which the data should be stored. key may be null.

Returns:

the key under which the data finally got stored.

Throws:

CreateException - if key does already exist and no other key was used.

writeOld

public void writeOld(java.lang.String key,
                     java.lang.Object data)
              throws javax.ejb.CreateException

Updates old data.

Parameters:

data - the data to be stored. A value of null will delete the data.

key - The key under which to store the data. key must not be null.

Throws:

CreateException - if key does not exist

read

public java.lang.Object read(java.lang.String key)

Read data stored at key.

Parameters:

key - The key to retrieve the data for. A value of null will return null.

Returns:

The object previously stored, or null if no such data exists.

Throws:

CreateException - if key does not exist