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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 }