1 /*
2 * LoggingWithAspectJ - Logging with AspectJ
3 * Copyright (C) 2007 Christian Schenk
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
18 */
19 package org.christianschenk.aspectj.logging;
20
21 import org.aspectj.lang.annotation.After;
22 import org.aspectj.lang.annotation.Aspect;
23 import org.aspectj.lang.annotation.Before;
24 import org.aspectj.lang.annotation.Pointcut;
25
26 /**
27 * This indented logging aspect was inspired by <a
28 * href="http://www.bibsonomy.org/bibtex/2684fcd95b8bce37858bcc13753047a7e/cschenk">AspectJ
29 * in Action</a> (p. 171).
30 *
31 * @author Christian Schenk
32 */
33 @Aspect
34 public abstract class AbstractLoggingAspect {
35
36 /** Indent width */
37 private final int width = 2;
38 /** Current indent with counter */
39 private int indent = 0;
40
41 /**
42 * This will be implemented by logging aspects.
43 */
44 @Pointcut
45 protected abstract void logging();
46
47 @Before("logging()")
48 public void increaseIndent() {
49 this.indent++;
50 }
51
52 @After("logging()")
53 public void decreaseIndent() {
54 this.indent--;
55 }
56
57 @Before("call(* java.io.PrintStream.println(..))")
58 public void print() {
59 for (int spaces = 0, indent = this.indent * this.width; spaces < indent; spaces++) {
60 System.out.print(" ");
61 }
62 }
63 }