org.apache.cayenne.PersistenceState Maven / Gradle / Ivy
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package org.apache.cayenne;
/**
* Defines a set of object states from the point of view of persistence. I.e.
* PersistenceState is the state of data stored in an object relative to the external
* persistence store. If an object's state matches the state of the persistence store, the
* object is COMMITTED. If object is not intended to be persistent or is not explicitly
* made persistent, the state is TRANSIENT, and so on.
*
* Object persistence states should not be modified directly. Rather it is a
* responsibility of a ObjectContext/DataContext to maintain correct state of the managed
* objects.
*
*/
public class PersistenceState {
/**
* Returns String label for persistence state. Used for debugging.
*/
public static String persistenceStateName(int persistenceState) {
switch (persistenceState) {
case PersistenceState.TRANSIENT:
return "transient";
case PersistenceState.NEW:
return "new";
case PersistenceState.MODIFIED:
return "modified";
case PersistenceState.COMMITTED:
return "committed";
case PersistenceState.HOLLOW:
return "hollow";
case PersistenceState.DELETED:
return "deleted";
default:
return "unknown";
}
}
/**
* Describes a state of an object not registered with DataContext/ObjectContext, and
* therefore having no persistence features.
*/
public static final int TRANSIENT = 1;
/**
* Describes a state of an object freshly registered with DataContext/ObjectContext,
* but not committed to the database yet. So there is no corresponding database record
* for this object just yet.
*/
public static final int NEW = 2;
/**
* Describes a state of an object registered with DataContext/ObjectContext, whose
* fields exactly match the state of a corresponding database row. This state is not
* fully "clean", since database record may have been externally modified.
*/
public static final int COMMITTED = 3;
/**
* Describes a state of an object registered with DataContext/ObjectContext, and
* having a corresponding database row. This object state is known to be locally
* modified and different from the database state.
*/
public static final int MODIFIED = 4;
/**
* Describes a state of an object registered with DataContext/ObjectContext, and
* having a corresponding database row. This object does not store any fields except
* for its id (it is "hollow"), so next time it is accessed, it will be populated from
* the database by the context. In this respect this is a real "clean" object.
*/
public static final int HOLLOW = 5;
/**
* Describes a state of an object registered with DataContext/ObjectContext, that will
* be deleted from the database on the next commit.
*/
public static final int DELETED = 6;
}