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.ASTClassDeclaration;
9 import net.sourceforge.pmd.ast.ASTCompilationUnit;
10 import net.sourceforge.pmd.ast.ASTConstructorDeclaration;
11 import net.sourceforge.pmd.ast.ASTFieldDeclaration;
12 import net.sourceforge.pmd.ast.ASTMethodDeclaration;
13 import net.sourceforge.pmd.ast.ASTUnmodifiedClassDeclaration;
14
15 public class UseSingletonRule extends AbstractRule {
16
17 private boolean isOK;
18 private int methodCount;
19
20 public Object visit(ASTCompilationUnit cu, Object data) {
21 methodCount = 0;
22 isOK = false;
23 Object result = cu.childrenAccept(this, data);
24 if (!isOK && methodCount > 0) {
25 RuleContext ctx = (RuleContext) data;
26 ctx.getReport().addRuleViolation(createRuleViolation(ctx, cu.getBeginLine()));
27 }
28
29 return result;
30 }
31
32 public Object visit(ASTFieldDeclaration decl, Object data) {
33 isOK = true;
34 return data;
35 }
36
37 public Object visit(ASTConstructorDeclaration decl, Object data) {
38 if (decl.isPrivate()) {
39 isOK = true;
40 }
41 return data;
42 }
43
44 public Object visit(ASTUnmodifiedClassDeclaration decl, Object data) {
45 if (decl.jjtGetParent() instanceof ASTClassDeclaration && ((ASTClassDeclaration)decl.jjtGetParent()).isAbstract()) {
46 isOK = true;
47 }
48 return super.visit(decl, data);
49 }
50
51 public Object visit(ASTMethodDeclaration decl, Object data) {
52 methodCount++;
53
54 if (!isOK && !decl.isStatic()) {
55 isOK = true;
56 }
57
58 return data;
59 }
60
61 }