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    1   /***
    2    * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
    3    */
    4   package net.sourceforge.pmd.rules.design;
    5
    6   import net.sourceforge.pmd.AbstractRule;
    7   import net.sourceforge.pmd.ast.ASTClassOrInterfaceType;
    8   import net.sourceforge.pmd.ast.ASTFieldDeclaration;
    9   import net.sourceforge.pmd.ast.ASTMethodDeclaration;
    10  import net.sourceforge.pmd.ast.ASTSynchronizedStatement;
    11  import net.sourceforge.pmd.ast.ASTVariableDeclaratorId;
    12  import net.sourceforge.pmd.ast.SimpleNode;
    13  import net.sourceforge.pmd.symboltable.NameOccurrence;
    14
    15  import java.util.HashSet;
    16  import java.util.Iterator;
    17  import java.util.Set;
    18
    19  /***
    20   * Using a DateFormatter (SimpleDateFormatter) which is static can cause
    21   * unexpected results when used in a multi threaded environment. This rule will
    22   * find static (Simple)DateFormatters which are used in an unsynchronized
    23   * manner.
    24   * Refer to these Bug Parade issues:
    25   * <a href="http://developer.java.sun.com/developer/bugParade/bugs/4093418.html">4093418</a>
    26   * <a href="http://developer.java.sun.com/developer/bugParade/bugs/4228335.html">4228335</a>
    27   * <a href="http://developer.java.sun.com/developer/bugParade/bugs/4261469.html">4261469</a>
    28   * see RFE1020790 - Check for SimpleDateFormat as singleton http://sourceforge.net/tracker/index.php?func=detail&aid=1020790&group_id=56262&atid=479924
    29   * @author Allan Caplan
    30   */
    31  public class UnsynchronizedStaticDateFormatter extends AbstractRule {
    32
    33      private static Set targets = new HashSet();
    34      static {
    35          targets.add("DateFormat");
    36          targets.add("SimpleDateFormat");
    37          targets.add("java.text.DateFormat");
    38          targets.add("java.text.SimpleDateFormat");
    39      }
    40
    41      public Object visit(ASTFieldDeclaration node, Object data) {
    42          if (!node.isStatic()) {
    43              return data;
    44          }
    45          ASTClassOrInterfaceType cit = (ASTClassOrInterfaceType) node.getFirstChildOfType(ASTClassOrInterfaceType.class);
    46          if (cit == null || !targets.contains(cit.getImage())) {
    47              return data;
    48          }
    49          ASTVariableDeclaratorId var = (ASTVariableDeclaratorId) node.getFirstChildOfType(ASTVariableDeclaratorId.class);
    50          for (Iterator i = var.getUsages().iterator(); i.hasNext();) {
    51              NameOccurrence occ = (NameOccurrence) i.next();
    52              SimpleNode n = occ.getLocation();
    53              if ((ASTSynchronizedStatement) n.getFirstParentOfType(ASTSynchronizedStatement.class) != null) {
    54                  continue;
    55              }
    56              ASTMethodDeclaration method = (ASTMethodDeclaration) n.getFirstParentOfType(ASTMethodDeclaration.class);
    57              if (method != null && !method.isSynchronized()) {
    58                  addViolation(data, n);
    59              }
    60          }
    61          return data;
    62      }
    63  }