ewe.database
Interface DataValidator

All Known Implementing Classes:

FieldModifier

public interface DataValidator

Method Summary

void	validateEntry(Database database, DatabaseEntry newData, DatabaseEntry oldData) This method can be used to either alter data before it is saved into the database or to abort a particular operation by throwing an InvalidDataException.

Method Detail

validateEntry

public void validateEntry(Database database,
                          DatabaseEntry newData,
                          DatabaseEntry oldData)
                   throws InvalidDataException,
                          IOException

This method can be used to either alter data before it is saved into the database or to abort a particular operation by throwing an InvalidDataException.

This method is called under four circumstances.

When a new DatabaseEntry is being saved - in which case the newData parameter holds the new data while the oldData parameter will be null.

When a DatabaseEntry is being modified - in which case the newData parameter holds the new data while the oldData parameter will hold the old data.

When a DatabaseEntry is being deleted - in which case the newData parameter will be null while the oldData parameter will hold the old data.

When a DatabaseEntry is being read - in which case the newData parameter refers to the same object as the oldData parameter (i.e. newData == oldData).

Parameters:

database - The Database that holds the data.

newData - The data being saved or changed or read. If you need to modify the data, then modify this parameter.

oldData - The original data before the change or deletion.

Throws:

InvalidDataException - If the operation should be disallowed due to bad data.

IOException