View Javadoc

1   /**
2    * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
3    */
4   package net.sourceforge.pmd.lang.java.rule.design;
5   
6   import java.util.Set;
7   
8   import net.sourceforge.pmd.lang.ast.Node;
9   import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType;
10  import net.sourceforge.pmd.lang.java.ast.ASTFieldDeclaration;
11  import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
12  import net.sourceforge.pmd.lang.java.ast.ASTSynchronizedStatement;
13  import net.sourceforge.pmd.lang.java.ast.ASTVariableDeclaratorId;
14  import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
15  import net.sourceforge.pmd.lang.symboltable.NameOccurrence;
16  import net.sourceforge.pmd.util.CollectionUtil;
17  
18  /**
19   * Using a DateFormatter (SimpleDateFormatter) which is static can cause
20   * unexpected results when used in a multi-threaded environment. This rule will
21   * find static (Simple)DateFormatters which are used in an unsynchronized
22   * manner.
23   * Refer to these Bug Parade issues:
24   * <a href="http://developer.java.sun.com/developer/bugParade/bugs/4093418.html">4093418</a>
25   * <a href="http://developer.java.sun.com/developer/bugParade/bugs/4228335.html">4228335</a>
26   * <a href="http://developer.java.sun.com/developer/bugParade/bugs/4261469.html">4261469</a>
27   * see RFE1020790 - Check for SimpleDateFormat as singleton http://sourceforge.net/tracker/index.php?func=detail&aid=1020790&group_id=56262&atid=479924
28   * @author Allan Caplan
29   */
30  public class UnsynchronizedStaticDateFormatterRule extends AbstractJavaRule {
31  
32      private static Set<String> targets = CollectionUtil.asSet(new String[] {
33      	"DateFormat", "SimpleDateFormat", "java.text.DateFormat","java.text.SimpleDateFormat"
34      	});
35  
36      @Override
37      public Object visit(ASTFieldDeclaration node, Object data) {
38          if (!node.isStatic()) {
39              return data;
40          }
41          ASTClassOrInterfaceType cit = node.getFirstDescendantOfType(ASTClassOrInterfaceType.class);
42          if (cit == null || !targets.contains(cit.getImage())) {
43              return data;
44          }
45          ASTVariableDeclaratorId var = node.getFirstDescendantOfType(ASTVariableDeclaratorId.class);
46          for (NameOccurrence occ: var.getUsages()) {
47              Node n = occ.getLocation();
48              if (n.getFirstParentOfType(ASTSynchronizedStatement.class) != null) {
49                  continue;
50              }
51              // ignore usages, that don't call a method.
52              if (!n.getImage().contains(".")) {
53                  continue;
54              }
55  
56              ASTMethodDeclaration method = n.getFirstParentOfType(ASTMethodDeclaration.class);
57              if (method != null && !method.isSynchronized()) {
58                  addViolation(data, n);
59              }
60          }
61          return data;
62      }
63  }