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1   package net.sourceforge.pmd.lang.java.rule.basic;
2   
3   import java.math.BigDecimal;
4   import java.math.BigInteger;
5   
6   import net.sourceforge.pmd.RuleContext;
7   import net.sourceforge.pmd.lang.LanguageVersion;
8   import net.sourceforge.pmd.lang.ast.Node;
9   import net.sourceforge.pmd.lang.java.ast.ASTAllocationExpression;
10  import net.sourceforge.pmd.lang.java.ast.ASTArguments;
11  import net.sourceforge.pmd.lang.java.ast.ASTArrayDimsAndInits;
12  import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType;
13  import net.sourceforge.pmd.lang.java.ast.ASTLiteral;
14  import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
15  import net.sourceforge.pmd.lang.java.typeresolution.TypeHelper;
16  
17  public class BigIntegerInstantiationRule extends AbstractJavaRule {
18  
19      @Override
20      public Object visit(ASTAllocationExpression node, Object data) {
21          Node type = node.jjtGetChild(0);
22  
23          if (!(type instanceof ASTClassOrInterfaceType)) {
24              return super.visit(node, data);
25          }
26  
27          boolean jdk15 = ((RuleContext) data).getLanguageVersion().compareTo(LanguageVersion.JAVA_15) >= 0;
28          if ((TypeHelper.isA((ASTClassOrInterfaceType) type, BigInteger.class) || jdk15 && TypeHelper.isA((ASTClassOrInterfaceType) type, BigDecimal.class)) &&
29                  !node.hasDescendantOfType(ASTArrayDimsAndInits.class)
30          ) {
31              ASTArguments args = node.getFirstChildOfType(ASTArguments.class);
32              if (args.getArgumentCount() == 1) {
33                  ASTLiteral literal = node.getFirstDescendantOfType(ASTLiteral.class);
34                  if (literal == null || literal.jjtGetParent().jjtGetParent().jjtGetParent().jjtGetParent().jjtGetParent() != args) {
35                      return super.visit(node, data);
36                  }
37  
38                  String img = literal.getImage();
39                  if (literal.isStringLiteral()) {
40                      img = img.substring(1, img.length() - 1);
41                  }
42  
43                  if ("0".equals(img) || "1".equals(img) || jdk15 && "10".equals(img)) {
44                      addViolation(data, node);
45                      return data;
46                  }
47              }
48          }
49          return super.visit(node, data);
50      }
51  
52  }