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.AbstractRule;
7 import net.sourceforge.pmd.RuleContext;
8 import net.sourceforge.pmd.ast.ASTClassOrInterfaceDeclaration;
9 import net.sourceforge.pmd.ast.ASTConstructorDeclaration;
10 import net.sourceforge.pmd.ast.ASTMethodDeclaration;
11 import net.sourceforge.pmd.ast.ASTVariableInitializer;
12 import net.sourceforge.pmd.ast.SimpleNode;
13 import net.sourceforge.pmd.symboltable.NameOccurrence;
14 import net.sourceforge.pmd.symboltable.VariableNameDeclaration;
15
16 import java.text.MessageFormat;
17 import java.util.HashSet;
18 import java.util.Iterator;
19 import java.util.List;
20 import java.util.Map;
21 import java.util.Set;
22
23 /***
24 * @author Olander
25 */
26 public class ImmutableField extends AbstractRule {
27
28 static private final int MUTABLE = 0;
29 static private final int IMMUTABLE = 1;
30 static private final int CHECKDECL = 2;
31
32 public Object visit(ASTClassOrInterfaceDeclaration node, Object data) {
33 Map vars = node.getScope().getVariableDeclarations();
34 Set constructors = findAllConstructors(node);
35 for (Iterator i = vars.keySet().iterator(); i.hasNext();) {
36 VariableNameDeclaration decl = (VariableNameDeclaration) i.next();
37 if (decl.getAccessNodeParent().isStatic() || !decl.getAccessNodeParent().isPrivate() || decl.getAccessNodeParent().isFinal()) {
38 continue;
39 }
40
41 int result = initializedInConstructor((List)vars.get(decl), new HashSet(constructors));
42 if (result == MUTABLE) {
43 continue;
44 }
45 if (result == IMMUTABLE || ((result == CHECKDECL) && initializedInDeclaration(decl.getAccessNodeParent()))) {
46 ((RuleContext) data).getReport().addRuleViolation(createRuleViolation((RuleContext) data, decl, MessageFormat.format(getMessage(), new Object[]{decl.getImage()})));
47 }
48 }
49 return super.visit(node, data);
50 }
51
52 private int initializedInConstructor(List usages, Set allConstructors) {
53 int rc = MUTABLE, methodInitCount = 0;
54 boolean foundUsage = false;
55 Set consSet = new HashSet();
56
57 for (Iterator j = usages.iterator(); j.hasNext();) {
58 foundUsage = true;
59 NameOccurrence occ = (NameOccurrence)j.next();
60 if (occ.isOnLeftHandSide() || occ.isSelfAssignment()) {
61 SimpleNode node = occ.getLocation();
62 SimpleNode constructor = (SimpleNode)node.getFirstParentOfType(ASTConstructorDeclaration.class);
63 if (constructor != null) {
64 consSet.add(constructor);
65 } else {
66 if (node.getFirstParentOfType(ASTMethodDeclaration.class) != null) {
67 methodInitCount++;
68 }
69 }
70 }
71 }
72 if (!foundUsage || ((methodInitCount == 0) && consSet.isEmpty())) {
73 rc = CHECKDECL;
74 } else {
75 allConstructors.removeAll(consSet);
76 if (allConstructors.isEmpty() && (methodInitCount == 0)) {
77 rc = IMMUTABLE;
78 }
79 }
80 return rc;
81 }
82
83 private boolean initializedInDeclaration(SimpleNode node) {
84 return !node.findChildrenOfType(ASTVariableInitializer.class).isEmpty();
85 }
86
87 /*** construct a set containing all ASTConstructorDeclaration nodes for this class
88 */
89 private Set findAllConstructors(ASTClassOrInterfaceDeclaration node) {
90 Set set = new HashSet();
91 set.addAll(node.findChildrenOfType(ASTConstructorDeclaration.class));
92 return set;
93 }
94 }