1 package net.sourceforge.pmd.lang.java.rule.strings;
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3 import java.util.HashSet;
4 import java.util.List;
5 import java.util.Set;
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7 import net.sourceforge.pmd.lang.ast.Node;
8 import net.sourceforge.pmd.lang.java.ast.ASTLiteral;
9 import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
10 import net.sourceforge.pmd.lang.java.ast.ASTName;
11 import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
12 import net.sourceforge.pmd.lang.java.symboltable.NameDeclaration;
13 import net.sourceforge.pmd.lang.java.symboltable.VariableNameDeclaration;
14 import net.sourceforge.pmd.lang.java.typeresolution.TypeHelper;
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33 public class UseStringBufferLengthRule extends AbstractJavaRule {
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45 private Set<VariableNameDeclaration> alreadySeen = new HashSet<VariableNameDeclaration>();
46
47 @Override
48 public Object visit(ASTMethodDeclaration acu, Object data) {
49 alreadySeen.clear();
50 return super.visit(acu, data);
51 }
52
53 @Override
54 public Object visit(ASTName decl, Object data) {
55 if (!decl.getImage().endsWith("toString")) {
56 return data;
57 }
58 NameDeclaration nd = decl.getNameDeclaration();
59 if (!(nd instanceof VariableNameDeclaration)) {
60 return data;
61 }
62 VariableNameDeclaration vnd = (VariableNameDeclaration) nd;
63 if (alreadySeen.contains(vnd) ||
64 TypeHelper.isNeither(vnd, StringBuffer.class, StringBuilder.class)) {
65 return data;
66 }
67 alreadySeen.add(vnd);
68
69 Node parent = decl.jjtGetParent().jjtGetParent();
70 for (int jx = 0; jx < parent.jjtGetNumChildren(); jx++) {
71 Node achild = parent.jjtGetChild(jx);
72 if (isViolation(parent, achild)) {
73 addViolation(data, decl);
74 }
75 }
76
77 return data;
78 }
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83 private boolean isViolation(Node parent, Node achild) {
84 if ("equals".equals(achild.getImage())) {
85 List<ASTLiteral> literals = parent.findDescendantsOfType(ASTLiteral.class);
86 return !literals.isEmpty() && "\"\"".equals(literals.get(0).getImage());
87 } else if ("length".equals(achild.getImage())) {
88 return true;
89 }
90 return false;
91 }
92 }