01: /*
02: * ====================================================================
03: * JAFFA - Java Application Framework For All
04: *
05: * Copyright (C) 2002 JAFFA Development Group
06: *
07: * This library is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU Lesser General Public
09: * License as published by the Free Software Foundation; either
10: * version 2.1 of the License, or (at your option) any later version.
11: *
12: * This library is distributed in the hope that it will be useful,
13: * but WITHOUT ANY WARRANTY; without even the implied warranty of
14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15: * Lesser General Public License for more details.
16: *
17: * You should have received a copy of the GNU Lesser General Public
18: * License along with this library; if not, write to the Free Software
19: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20: *
21: * Redistribution and use of this software and associated documentation ("Software"),
22: * with or without modification, are permitted provided that the following conditions are met:
23: * 1. Redistributions of source code must retain copyright statements and notices.
24: * Redistributions must also contain a copy of this document.
25: * 2. Redistributions in binary form must reproduce the above copyright notice,
26: * this list of conditions and the following disclaimer in the documentation
27: * and/or other materials provided with the distribution.
28: * 3. The name "JAFFA" must not be used to endorse or promote products derived from
29: * this Software without prior written permission. For written permission,
30: * please contact mail to: jaffagroup@yahoo.com.
31: * 4. Products derived from this Software may not be called "JAFFA" nor may "JAFFA"
32: * appear in their names without prior written permission.
33: * 5. Due credit should be given to the JAFFA Project (http://jaffa.sourceforge.net).
34: *
35: * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
36: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
39: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46: * SUCH DAMAGE.
47: * ====================================================================
48: */
49:
50: package org.jaffa.persistence.engines.jdbcengine.interceptor;
51:
52: import org.jaffa.persistence.engines.jdbcengine.datasource.PersistentTransaction;
53: import org.jaffa.persistence.exceptions.UOWException;
54:
55: /** This is the abstract class for an Interceptor. All new interceptors must
56: * inherit from this base class. A set of interceptors exists the Engine.
57: */
58: public abstract class AbstractInterceptor {
59:
60: /** The next interceptor in the invocation chain */
61: private AbstractInterceptor m_next;
62:
63: /** Sets the next Interceptor in the chain.
64: *@param next the next Interceptor in the chain.
65: */
66: public void setNextInterceptor(AbstractInterceptor next) {
67: m_next = next;
68: }
69:
70: /** Returns the next Interceptor in the chain. A null will be returned in case this is the end of the chain.
71: * @return the next Interceptor in the chain.
72: */
73: public AbstractInterceptor getNextInterceptor() {
74: return m_next;
75: }
76:
77: /**Performs the actual logic associated with the interceptor.
78: * Should contain atomic logic, i.e., does not assumes input or output of other interceptors in the chain.
79: * @param pt The PersistentTransaction object, on which the Interceptor is to be executed.
80: * @throws UOWException if any error occurs.
81: * @return the output from the next Interceptor in the chain.
82: */
83: public abstract Object invoke(PersistentTransaction pt)
84: throws UOWException;
85: }
|