1 package net.sourceforge.pmd.rules.optimization;
2
3 import net.sourceforge.pmd.AbstractRule;
4 import net.sourceforge.pmd.ast.ASTAssignmentOperator;
5 import net.sourceforge.pmd.ast.ASTLocalVariableDeclaration;
6 import net.sourceforge.pmd.ast.ASTName;
7 import net.sourceforge.pmd.ast.ASTPrimaryExpression;
8 import net.sourceforge.pmd.ast.ASTStatementExpression;
9 import net.sourceforge.pmd.ast.ASTVariableDeclaratorId;
10 import net.sourceforge.pmd.ast.Node;
11 import net.sourceforge.pmd.ast.SimpleNode;
12 import net.sourceforge.pmd.symboltable.NameOccurrence;
13
14 import java.util.Iterator;
15
16 public class UseStringBufferForStringAppends extends AbstractRule {
17
18 public Object visit(ASTVariableDeclaratorId node, Object data) {
19 if (node.getTypeNameNode().jjtGetNumChildren() == 0 || !"String".equals(((SimpleNode) node.getTypeNameNode().jjtGetChild(0)).getImage())) {
20 return data;
21 }
22 Node parent = node.jjtGetParent().jjtGetParent();
23 if (!parent.getClass().equals(ASTLocalVariableDeclaration.class)) {
24 return data;
25 }
26 for (Iterator iter = node.getUsages().iterator(); iter.hasNext();) {
27 NameOccurrence no = (NameOccurrence) iter.next();
28 SimpleNode name = (SimpleNode) no.getLocation();
29 ASTStatementExpression statement = (ASTStatementExpression) name.getFirstParentOfType(ASTStatementExpression.class);
30 if (statement == null) {
31 continue;
32 }
33 if (statement.jjtGetNumChildren() > 0 && statement.jjtGetChild(0).getClass().equals(ASTPrimaryExpression.class)) {
34
35
36
37 ASTName astName = (ASTName) ((SimpleNode) statement.jjtGetChild(0)).getFirstChildOfType(ASTName.class);
38 if (astName != null && astName.equals(name)) {
39 ASTAssignmentOperator assignmentOperator = (ASTAssignmentOperator) statement.getFirstChildOfType(ASTAssignmentOperator.class);
40 if (assignmentOperator != null && assignmentOperator.isCompound()) {
41 addViolation(data, assignmentOperator);
42 }
43 }
44 }
45 }
46
47 return data;
48 }
49 }