001/* 002 * HA-JDBC: High-Availability JDBC 003 * Copyright (C) 2012 Paul Ferraro 004 * 005 * This program is free software: you can redistribute it and/or modify 006 * it under the terms of the GNU Lesser General Public License as published by 007 * the Free Software Foundation, either version 3 of the License, or 008 * (at your option) any later version. 009 * 010 * This program is distributed in the hope that it will be useful, 011 * but WITHOUT ANY WARRANTY; without even the implied warranty of 012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 013 * GNU Lesser General Public License for more details. 014 * 015 * You should have received a copy of the GNU Lesser General Public License 016 * along with this program. If not, see <http://www.gnu.org/licenses/>. 017 */ 018package net.sf.hajdbc.lock.distributed; 019 020import java.util.Map; 021import java.util.concurrent.locks.Lock; 022 023import net.sf.hajdbc.distributed.Command; 024 025/** 026 * Release lock command for execution on group member. 027 * @author Paul Ferraro 028 */ 029public class MemberReleaseLockCommand implements Command<Void, LockCommandContext> 030{ 031 private static final long serialVersionUID = -4088487420468046409L; 032 033 private final RemoteLockDescriptor descriptor; 034 035 public MemberReleaseLockCommand(RemoteLockDescriptor descriptor) 036 { 037 this.descriptor = descriptor; 038 } 039 040 /** 041 * {@inheritDoc} 042 * @see net.sf.hajdbc.distributed.Command#execute(java.lang.Object) 043 */ 044 @Override 045 public Void execute(LockCommandContext context) 046 { 047 Map<LockDescriptor, Lock> locks = context.getRemoteLocks(this.descriptor); 048 049 if (locks != null) 050 { 051 Lock lock = null; 052 053 synchronized (locks) 054 { 055 lock = locks.remove(this.descriptor); 056 } 057 058 if (lock != null) 059 { 060 lock.unlock(); 061 } 062 } 063 064 return null; 065 } 066 067 /** 068 * {@inheritDoc} 069 * @see java.lang.Object#toString() 070 */ 071 @Override 072 public String toString() 073 { 074 return String.format("%s(%s)", this.getClass().getSimpleName(), this.descriptor); 075 } 076}