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1   package net.sourceforge.pmd.rules.basic;
2   
3   import net.sourceforge.pmd.AbstractRule;
4   import net.sourceforge.pmd.ast.ASTAllocationExpression;
5   import net.sourceforge.pmd.ast.ASTArrayDimsAndInits;
6   import net.sourceforge.pmd.ast.ASTBooleanLiteral;
7   import net.sourceforge.pmd.ast.ASTClassOrInterfaceType;
8   import net.sourceforge.pmd.ast.ASTCompilationUnit;
9   import net.sourceforge.pmd.ast.ASTImportDeclaration;
10  import net.sourceforge.pmd.ast.ASTLiteral;
11  import net.sourceforge.pmd.ast.ASTName;
12  import net.sourceforge.pmd.ast.ASTPrimaryExpression;
13  import net.sourceforge.pmd.ast.ASTPrimaryPrefix;
14  import net.sourceforge.pmd.ast.ASTPrimarySuffix;
15  import net.sourceforge.pmd.typeresolution.TypeHelper;
16  
17  /**
18   * Avoid instantiating Boolean objects; you can reference Boolean.TRUE,
19   * Boolean.FALSE, or call Boolean.valueOf() instead.
20   *
21   * <pre>
22   *  public class Foo {
23   *       Boolean bar = new Boolean("true");    // just do a Boolean
24   *       bar = Boolean.TRUE;                   //ok
25   *       Boolean buz = Boolean.valueOf(false); // just do a Boolean buz = Boolean.FALSE;
26   *  }
27   * </pre>
28   */
29  public class BooleanInstantiation extends AbstractRule {
30  
31  	/*
32  	 *  see bug 1744065 : If somebody create it owns Boolean, the rule should not be triggered
33  	 *   Therefore, we use this boolean to flag if the source code contains such an import
34  	 *
35  	 */
36  	private boolean customBoolean;
37  
38      public Object visit(ASTCompilationUnit decl,Object data) {
39          // customBoolean needs to be reset for each new file
40          customBoolean = false;
41  
42          return super.visit(decl, data);
43      }
44  
45  	public Object visit(ASTImportDeclaration decl,Object data) {
46  		// If the import actually import a Boolean class that overrides java.lang.Boolean
47  		if ( decl.getImportedName().endsWith("Boolean") && ! decl.getImportedName().equals("java.lang"))
48  		{
49  			customBoolean = true;
50  		}
51  		return super.visit(decl, data);
52  	}
53  
54      public Object visit(ASTAllocationExpression node, Object data) {
55  
56      	if ( ! customBoolean ) {
57  	        if (node.findChildrenOfType(ASTArrayDimsAndInits.class).size() > 0) {
58  	            return super.visit(node, data);
59  	        }
60  	        if (TypeHelper.isA((ASTClassOrInterfaceType) node.jjtGetChild(0), Boolean.class)) {
61                  super.addViolation(data, node);
62                  return data;
63              }
64      	}
65          return super.visit(node, data);
66      }
67  
68      public Object visit(ASTPrimaryPrefix node, Object data) {
69  
70      	if ( ! customBoolean )
71      	{
72  	        if (node.jjtGetNumChildren() == 0 || !node.jjtGetChild(0).getClass().equals(ASTName.class)) {
73  	            return super.visit(node, data);
74  	        }
75  
76  	        if ("Boolean.valueOf".equals(((ASTName) node.jjtGetChild(0)).getImage())
77  	                || "java.lang.Boolean.valueOf".equals(((ASTName) node.jjtGetChild(0)).getImage())) {
78  	            ASTPrimaryExpression parent = (ASTPrimaryExpression) node.jjtGetParent();
79  	            ASTPrimarySuffix suffix = parent.getFirstChildOfType(ASTPrimarySuffix.class);
80  	            if (suffix == null) {
81  	                return super.visit(node, data);
82  	            }
83  	            ASTPrimaryPrefix prefix = suffix.getFirstChildOfType(ASTPrimaryPrefix.class);
84  	            if (prefix == null) {
85  	                return super.visit(node, data);
86  	            }
87  
88  	            if (prefix.getFirstChildOfType(ASTBooleanLiteral.class) != null) {
89  	                super.addViolation(data, node);
90  	                return data;
91  	            }
92  	            ASTLiteral literal = prefix.getFirstChildOfType(ASTLiteral.class);
93  	            if (literal != null && ("\"true\"".equals(literal.getImage()) || "\"false\"".equals(literal.getImage()))) {
94  	                super.addViolation(data, node);
95  	                return data;
96  	            }
97  	        }
98      	}
99          return super.visit(node, data);
100     }
101 }