Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ConstructorFilter |
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| 0.0;0 |
1 | /* | |
2 | * Copyright (c) 2003-2008, by Henrik Arro and Contributors | |
3 | * | |
4 | * This file is part of JSeq, a tool to automatically create | |
5 | * sequence diagrams by tracing program execution. | |
6 | * | |
7 | * See <http://jseq.sourceforge.net> for more information. | |
8 | * | |
9 | * JSeq is free software: you can redistribute it and/or modify | |
10 | * it under the terms of the GNU Lesser General Public License as | |
11 | * published by the Free Software Foundation, either version 3 of | |
12 | * the License, or (at your option) any later version. | |
13 | * | |
14 | * JSeq is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public License | |
20 | * along with JSeq. If not, see <http://www.gnu.org/licenses/>. | |
21 | */ | |
22 | ||
23 | package th.co.edge.jseq; | |
24 | ||
25 | import com.sun.jdi.Method; | |
26 | ||
27 | import th.co.edge.jseq.ActivationList.Filter; | |
28 | ||
29 | /** | |
30 | * A <code>Filter</code> that accepts all methods, except constructors that | |
31 | * are either synthetic (automatically created by the compiler), or are calls to | |
32 | * <code>super</code>. | |
33 | * | |
34 | * <p> | |
35 | * The reason that this filter was created was to remove "unnecessary" calls to | |
36 | * <code><init></code> from the sequence diagrams. Since the sequence | |
37 | * diagrams generated by JSeq are class-based, not instance-based (i.e., each | |
38 | * lifeline belongs to a class, not to a specific instance), and since the class | |
39 | * of the instance being called is used (not the declaring class), calls to | |
40 | * synthetic constructors or to the super constructor would be represented as | |
41 | * one or several calls to <code><init></code> back to the same class. | |
42 | * This was deemed more confusing than helpful. | |
43 | * | |
44 | * <p> | |
45 | * In order to determine if a call is a call to a super-class constructor, this | |
46 | * filter needs access to a <code>ClassLoader</code>. When running JSeq | |
47 | * stand-alone, this is not a problem, but when attaching to a running process, | |
48 | * JSeq should have the same classpath as that process. If not, the only effect | |
49 | * is that the "unnecessary" constructor calls are included in the diagram, so | |
50 | * failure to set up the correct classpath when attaching to a process is far | |
51 | * from catastrophic. | |
52 | * | |
53 | * <p> | |
54 | * This filter was created after Jacek Ratzinger supplied his patch (<a | |
55 | * href="https://sourceforge.net/tracker/index.php?func=detail&aid=2027500&group_id=230519&atid=1080393" | |
56 | * target="new">SourceForge issue 2027500</a>) since that change made calls to | |
57 | * the super-class constructor look as calls back to the same class. In the | |
58 | * process it also turned out that private nested classes use a synthetic | |
59 | * constructor that need not be shown in the generated sequence diagrams. | |
60 | */ | |
61 | public class ConstructorFilter implements Filter { | |
62 | private ClassLoader classLoader; | |
63 | ||
64 | /** | |
65 | * Creates a new <code>ConstructorFilter</code> that uses the given | |
66 | * <code>ClassLoader</code> to determine if a call is to a super-class | |
67 | * constructor. | |
68 | * | |
69 | * @param classLoader | |
70 | * a <code>ClassLoader</code> that should match that of the | |
71 | * process being traced | |
72 | */ | |
73 | 0 | public ConstructorFilter(ClassLoader classLoader) { |
74 | 0 | this.classLoader = classLoader; |
75 | 0 | } |
76 | ||
77 | /** | |
78 | * Returns <code>true</code> for all <code>Activation</code>s, except | |
79 | * calls to synthetic constructors and calls to super-class constructors. | |
80 | * | |
81 | * @param activation | |
82 | * the <code>Activation</code> to check | |
83 | * | |
84 | * @return <code>false</code> if <code>activation</code> represents a | |
85 | * call to a synthetic constructor or a call to a super-class | |
86 | * constructor, <code>true</code> otherwise | |
87 | */ | |
88 | @Override | |
89 | public boolean accept(Activation activation) { | |
90 | 0 | boolean accepted = true; |
91 | 0 | Method method = activation.getMethod(); |
92 | 0 | if (method.isConstructor() && activation.getParent() != null) { |
93 | 0 | Activation parentActivation = activation.getParent(); |
94 | 0 | Method parentMethod = parentActivation.getMethod(); |
95 | 0 | if (parentMethod != null && parentMethod.isConstructor()) { |
96 | 0 | if (parentMethod.isSynthetic()) { |
97 | 0 | accepted = false; |
98 | 0 | } else if (isDeclaredInSuperclass(method, parentMethod)) { |
99 | 0 | accepted = false; |
100 | } | |
101 | } | |
102 | } | |
103 | 0 | return accepted; |
104 | } | |
105 | ||
106 | /** | |
107 | * Returns <code>true</code> if the method <code>m1</code> is declared | |
108 | * in a superclass to the class that declares the method <code>m2</code>. | |
109 | * | |
110 | * @param m1 | |
111 | * method from superclass? | |
112 | * @param m2 | |
113 | * method from subclass? | |
114 | * | |
115 | * @return <code>true</code> if <code>m1</code> is declared in a | |
116 | * superclass to the class where <code>m2</code> is declared | |
117 | */ | |
118 | private boolean isDeclaredInSuperclass(Method m1, Method m2) { | |
119 | 0 | boolean fromSuperclass = false; |
120 | try { | |
121 | 0 | Class<?> c1 = classLoader.loadClass(m1.declaringType().name()); |
122 | 0 | Class<?> c2 = classLoader.loadClass(m2.declaringType().name()); |
123 | 0 | if (c1.isAssignableFrom(c2) && !c1.equals(c2)) { |
124 | 0 | fromSuperclass = true; |
125 | } | |
126 | 0 | } catch (Exception e) { |
127 | 0 | System.err.println(e); |
128 | 0 | } |
129 | 0 | return fromSuperclass; |
130 | } | |
131 | } |