KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > net > sourceforge > pmd > rules > design > SwitchDensityRule


1 /**
2  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
3  */
4 package net.sourceforge.pmd.rules.design;
5
6 import net.sourceforge.pmd.ast.ASTStatement;
7 import net.sourceforge.pmd.ast.ASTSwitchLabel;
8 import net.sourceforge.pmd.ast.ASTSwitchStatement;
9 import net.sourceforge.pmd.stat.DataPoint;
10 import net.sourceforge.pmd.stat.StatisticalRule;
11
12 /**
13  * @author dpeugh
14  * <p/>
15  * Switch Density - This is the number of statements over the
16  * number of cases within a switch. The higher the value, the
17  * more work each case is doing.
18  * <p/>
19  * Its my theory, that when the Switch Density is high, you should
20  * start looking at Subclasses or State Pattern to alleviate the
21  * problem.
22  */
23 public class SwitchDensityRule extends StatisticalRule {
24
25     private static class SwitchDensity {
26         private int labels = 0;
27         private int stmts = 0;
28
29         public void addSwitchLabel() {
30             labels++;
31         }
32
33         public void addStatement() {
34             stmts++;
35         }
36
37         public void addStatements(int stmtCount) {
38             stmts += stmtCount;
39         }
40
41         public int getStatementCount() {
42             return stmts;
43         }
44
45         public double getDensity() {
46             if (labels == 0) {
47                 return 0;
48             }
49             return (double) stmts / (double) labels;
50         }
51     }
52
53     public Object JavaDoc visit(ASTSwitchStatement node, Object JavaDoc data) {
54         SwitchDensity oldData = null;
55
56         if (data instanceof SwitchDensity) {
57             oldData = (SwitchDensity) data;
58         }
59
60         SwitchDensity density = new SwitchDensity();
61
62         node.childrenAccept(this, density);
63
64         DataPoint point = new DataPoint();
65         point.setNode(node);
66         point.setScore(density.getDensity());
67         point.setMessage(getMessage());
68
69         addDataPoint(point);
70
71         if (data instanceof SwitchDensity) {
72             ((SwitchDensity) data).addStatements(density.getStatementCount());
73         }
74         return oldData;
75     }
76
77     public Object JavaDoc visit(ASTStatement statement, Object JavaDoc data) {
78         if (data instanceof SwitchDensity) {
79             ((SwitchDensity) data).addStatement();
80         }
81
82         statement.childrenAccept(this, data);
83
84         return data;
85     }
86
87     public Object JavaDoc visit(ASTSwitchLabel switchLabel, Object JavaDoc data) {
88         if (data instanceof SwitchDensity) {
89             ((SwitchDensity) data).addSwitchLabel();
90         }
91
92         switchLabel.childrenAccept(this, data);
93         return data;
94     }
95 }
96
Popular Tags