1 package net.sourceforge.pmd.rules.optimization;
2
3 import net.sourceforge.pmd.AbstractRule;
4 import net.sourceforge.pmd.ast.ASTArgumentList;
5 import net.sourceforge.pmd.ast.ASTAssignmentOperator;
6 import net.sourceforge.pmd.ast.ASTLocalVariableDeclaration;
7 import net.sourceforge.pmd.ast.ASTName;
8 import net.sourceforge.pmd.ast.ASTPrimaryExpression;
9 import net.sourceforge.pmd.ast.ASTStatementExpression;
10 import net.sourceforge.pmd.ast.ASTVariableDeclaratorId;
11 import net.sourceforge.pmd.ast.Node;
12 import net.sourceforge.pmd.ast.SimpleNode;
13 import net.sourceforge.pmd.symboltable.NameOccurrence;
14 import net.sourceforge.pmd.typeresolution.TypeHelper;
15
16 public class UseStringBufferForStringAppends extends AbstractRule {
17
18 @Override
19 public Object visit(ASTVariableDeclaratorId node, Object data) {
20 if (!TypeHelper.isA(node, String.class) || node.isArray()) {
21 return data;
22 }
23 Node parent = node.jjtGetParent().jjtGetParent();
24 if (!parent.getClass().equals(ASTLocalVariableDeclaration.class)) {
25 return data;
26 }
27 for (NameOccurrence no: node.getUsages()) {
28 SimpleNode name = no.getLocation();
29 ASTStatementExpression statement = name.getFirstParentOfType(ASTStatementExpression.class);
30 if (statement == null) {
31 continue;
32 }
33 ASTArgumentList argList = name.getFirstParentOfType(ASTArgumentList.class);
34 if (argList != null && argList.getFirstParentOfType(ASTStatementExpression.class) == statement) {
35
36 continue;
37 }
38 if (statement.jjtGetNumChildren() > 0 && statement.jjtGetChild(0).getClass().equals(ASTPrimaryExpression.class)) {
39 ASTName astName = ((SimpleNode) statement.jjtGetChild(0)).getFirstChildOfType(ASTName.class);
40 if(astName != null){
41 if (astName.equals(name)) {
42 ASTAssignmentOperator assignmentOperator = statement.getFirstChildOfType(ASTAssignmentOperator.class);
43 if (assignmentOperator != null && assignmentOperator.isCompound()) {
44 addViolation(data, assignmentOperator);
45 }
46 } else if(astName.getImage().equals(name.getImage())){
47 ASTAssignmentOperator assignmentOperator = statement.getFirstChildOfType(ASTAssignmentOperator.class);
48 if (assignmentOperator != null && !assignmentOperator.isCompound()) {
49 addViolation(data, astName);
50 }
51 }
52 }
53 }
54 }
55 return data;
56 }
57 }