Mercurial > hg > blitz_condensed
diff src/org/prevayler/Command.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/prevayler/Command.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,53 @@ +/* + The copyright of all source code included in this Prevayler distribution is + held by Klaus Wuestefeld, except the files that specifically state otherwise. + All rights are reserved. "PREVAYLER" is a trademark of Klaus Wuestefeld. + + + BSD License: + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + - Redistributions of source code must retain the above copyright notice, this + list of conditions and the following disclaimer. + + - Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + - Neither the name of Prevayler nor the names of its contributors may be used + to endorse or promote products derived from this software without specific + prior written permission. + + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. +*/ + +package org.prevayler; + +import java.io.Serializable; + + +/** + * An atomic transaction to be executed on a PrevalentSystem. Any operation which changes the observable state of a PrevalentSystem must be encapsulated as a Command. + */ +public interface Command extends Serializable { + + /** + * Executes this command on the received system. See org.prevayler.demos for examples. The returned object has to be Serializable in preparation for future versions of Prevayler that will provide fault-tolerance through system replicas. + * @return The object returned by the execution of this command. Most commands simply return null. + */ + public Serializable execute(PrevalentSystem system) throws Exception; + +}