/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import org.hibernate.type.VersionType;
/**
* Represents a replication strategy.
*
* @see Session#replicate(Object, ReplicationMode)
* @author Gavin King
*/
public abstract class ReplicationMode
implements Serializable {
private final String name
;
private static final Map INSTANCES =
new HashMap();
public ReplicationMode
(String name
) {
this.
name=name
;
}
public String toString
() {
return name
;
}
public abstract boolean shouldOverwriteCurrentVersion
(Object entity,
Object currentVersion,
Object newVersion, VersionType versionType
);
/**
* Throw an exception when a row already exists.
*/
public static final ReplicationMode EXCEPTION =
new ReplicationMode
("EXCEPTION") {
public boolean shouldOverwriteCurrentVersion
(Object entity,
Object currentVersion,
Object newVersion, VersionType versionType
) {
throw new AssertionFailure
("should not be called");
}
};
/**
* Ignore replicated entities when a row already exists.
*/
public static final ReplicationMode IGNORE =
new ReplicationMode
("IGNORE") {
public boolean shouldOverwriteCurrentVersion
(Object entity,
Object currentVersion,
Object newVersion, VersionType versionType
) {
return false;
}
};
/**
* Overwrite existing rows when a row already exists.
*/
public static final ReplicationMode OVERWRITE =
new ReplicationMode
("OVERWRITE") {
public boolean shouldOverwriteCurrentVersion
(Object entity,
Object currentVersion,
Object newVersion, VersionType versionType
) {
return true;
}
};
/**
* When a row already exists, choose the latest version.
*/
public static final ReplicationMode LATEST_VERSION =
new ReplicationMode
("LATEST_VERSION") {
public boolean shouldOverwriteCurrentVersion
(Object entity,
Object currentVersion,
Object newVersion, VersionType versionType
) {
if (versionType==
null) return true; //always overwrite nonversioned data
return versionType.
getComparator().
compare(currentVersion, newVersion
) <=
0;
}
};
static {
INSTANCES.
put( LATEST_VERSION.
name, LATEST_VERSION
);
INSTANCES.
put( IGNORE.
name, IGNORE
);
INSTANCES.
put( OVERWRITE.
name, OVERWRITE
);
INSTANCES.
put( EXCEPTION.
name, EXCEPTION
);
}
private Object readResolve
() {
return INSTANCES.
get(name
);
}
}