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Java > Open Source Codes > org > codehaus > aspectwerkz > util > Util


1 /**************************************************************************************
2  * Copyright (c) Jonas BonŽr, Alexandre Vasseur. All rights reserved. *
3  * http://aspectwerkz.codehaus.org *
4  * ---------------------------------------------------------------------------------- *
5  * The software in this package is published under the terms of the LGPL license *
6  * a copy of which has been included with this distribution in the license.txt file. *
7  **************************************************************************************/
8 package org.codehaus.aspectwerkz.util;
9
10 import org.codehaus.aspectwerkz.reflect.ReflectionInfo;
11
12 /**
13  * Utility methods and constants used in the AspectWerkz system.
14  *
15  * @author <a HREF="mailto:jboner@codehaus.org">Jonas BonŽr </a>
16  */
17 public final class Util {
18     public static final Integer JavaDoc INTEGER_DEFAULT_VALUE = new Integer JavaDoc(0);
19
20     public static final Float JavaDoc FLOAT_DEFAULT_VALUE = new Float JavaDoc(0.0f);
21
22     public static final Double JavaDoc DOUBLE_DEFAULT_VALUE = new Double JavaDoc(0.0d);
23
24     public static final Long JavaDoc LONG_DEFAULT_VALUE = new Long JavaDoc(0L);
25
26     public static final Boolean JavaDoc BOOLEAN_DEFAULT_VALUE = new Boolean JavaDoc(false);
27
28     public static final Character JavaDoc CHARACTER_DEFAULT_VALUE = new Character JavaDoc('\u0000');
29
30     public static final Short JavaDoc SHORT_DEFAULT_VALUE;
31
32     public static final Byte JavaDoc BYTE_DEFAULT_VALUE;
33
34     static {
35         byte b = 0;
36         BYTE_DEFAULT_VALUE = new Byte JavaDoc(b);
37         short s = 0;
38         SHORT_DEFAULT_VALUE = new Short JavaDoc(s);
39     }
40
41     /**
42      * Calculates the hash for the class name and the meta-data.
43      *
44      * @param className the class name
45      * @param info the meta-data
46      * @return the hash
47      */
48     public static Integer JavaDoc calculateHash(final String JavaDoc className, final ReflectionInfo info) {
49         if (className == null) {
50             throw new IllegalArgumentException JavaDoc("class name can not be null");
51         }
52         if (info == null) {
53             throw new IllegalArgumentException JavaDoc("info can not be null");
54         }
55         int hash = 17;
56         hash = (37 * hash) + className.hashCode();
57         hash = (37 * hash) + info.hashCode();
58         Integer JavaDoc hashKey = new Integer JavaDoc(hash);
59         return hashKey;
60     }
61
62     /**
63      * Removes the AspectWerkz specific elements from the stack trace. <p/>TODO: how to mess w/ the stacktrace in JDK
64      * 1.3.x?
65      *
66      * @param exception the Throwable to modify the stack trace on
67      * @param className the name of the fake origin class of the exception
68      */
69     public static void fakeStackTrace(final Throwable JavaDoc exception, final String JavaDoc className) {
70         if (exception == null) {
71             throw new IllegalArgumentException JavaDoc("exception can not be null");
72         }
73         if (className == null) {
74             throw new IllegalArgumentException JavaDoc("class name can not be null");
75         }
76
77         // final List newStackTraceList = new ArrayList();
78 // final StackTraceElement[] stackTrace = exception.getStackTrace();
79 // int i;
80 // for (i = 1; i < stackTrace.length; i++) {
81 // if (stackTrace[i].getClassName().equals(className)) break;
82 // }
83 // for (int j = i; j < stackTrace.length; j++) {
84 // newStackTraceList.add(stackTrace[j]);
85 // }
86 //
87 // final StackTraceElement[] newStackTrace =
88 // new StackTraceElement[newStackTraceList.size()];
89 // int k = 0;
90 // for (Iterator it = newStackTraceList.iterator(); it.hasNext(); k++) {
91 // final StackTraceElement element = (StackTraceElement)it.next();
92 // newStackTrace[k] = element;
93 // }
94 // exception.setStackTrace(newStackTrace);
95 }
96
97     /**
98      * Returns a String representation of a classloader Avoid to do a toString() if the resulting string is too long
99      * (occurs on Tomcat)
100      *
101      * @param loader
102      * @return String representation (toString or FQN@hashcode)
103      */
104     public static String JavaDoc classLoaderToString(ClassLoader JavaDoc loader) {
105         if ((loader != null) && (loader.toString().length() < 120)) {
106             return loader.toString() + "@" + loader.hashCode();
107         } else if (loader != null) {
108             return loader.getClass().getName() + "@" + loader.hashCode();
109         } else {
110             return "null";
111         }
112     }
113
114     /**
115      * Helper method to support Java 1.4 like Boolean.valueOf(boolean) in Java 1.3
116
117      * @param b
118      * @return
119      */
120     public static Boolean JavaDoc booleanValueOf(boolean b) {
121         return b?Boolean.TRUE:Boolean.FALSE;
122     }
123 }
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