com.cedarsoft.gdao.GenericService Maven / Gradle / Ivy
/**
* Copyright (C) cedarsoft GmbH.
*
* Licensed under the GNU General Public License version 3 (the "License")
* with Classpath Exception; you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.cedarsoft.org/gpl3ce
* (GPL 3 with Classpath Exception)
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 only, as
* published by the Free Software Foundation. cedarsoft GmbH designates this
* particular file as subject to the "Classpath" exception as provided
* by cedarsoft GmbH in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 3 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 3 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact cedarsoft GmbH, 72810 Gomaringen, Germany,
* or visit www.cedarsoft.com if you need additional information or
* have any questions.
*/
package com.cedarsoft.gdao;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.lang.Override;
/**
* A generic service that extends the behaviour of simple DAOs with transaction support.
*/
public interface GenericService extends GenericDao {
/**
* Performs an action within an transaction.
*
* @param callback the callback that is called within a transaction
* @return the return value (optional)
*/
@Nullable
R perform( @NotNull ServiceCallback callback );
/**
* A callback that can be used to be invoked within a service (in a transaction).
*/
interface ServiceCallback {
/**
* Perform the action
*
* @param service the service
* @return the return value (may be null)
*/
@Nullable
R perform( @NotNull GenericService service );
}
/**
* Abstract base class for service callbacks without return value.
*/
abstract class ServiceCallbackWithoutReturnValue implements ServiceCallback {
@Override
@Nullable
public Object perform( @NotNull GenericService service ) {
performVoid( service );
return null;
}
/**
* Perform the action without any return value
*
* @param service the service
*/
protected abstract void performVoid( @NotNull GenericService service );
}
}