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  1. JDK
  2. JDK-6213298

File.renameTo() sometimes doesn't work even if the new file name doesn't exist

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P4
    • Resolution: Duplicate
    • Affects Version/s: 1.4.2_05, 5.0
    • Fix Version/s: None
    • Component/s: core-libs
    • Labels:
    • Subcomponent:
    • CPU:
      x86
    • OS:
      windows_2000, windows_2003

      Description

      FULL PRODUCT VERSION :
      java version "1.5.0"
      java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
      Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode)

      ADDITIONAL OS VERSION INFORMATION :
      Windows 2000 V5.0 Build 2195: SP4

      A DESCRIPTION OF THE PROBLEM :
      After releasing a File object, another File object for the same file name cannot be renamed immediately. Here's my work-around that usually works but still sometimes fails.

      public class XFile extends File
         {

         /*
         ==============================================================
         ============================================================== *//**
         This method is a cover for File.renameTo(). The motivation for this
         cover method is that with this new version of Java (1.5.0), rename (and
         other file methods) sometimes don't work on the first try. This seems to
         be because file objects that have been closed are hung onto, pending
         garbage collection.

         @return
            true if and only if the renaming succeeded; false otherwise

         @param
            pNewFile is a File object containing the new name for the file.
         *//*
         -------------------------------------------------------------- */
         public boolean renameTo(File pNewFile)
            {
            /*
            ===============================================
            HACK - I should just be able to call renameTo() here and return its
            result. In fact, I used to do just that and this method always worked
            fine. Now with this new version of Java (1.5.0), rename (and other
            file methods) sometimes don't work on the first try. This is because
            file objects that have been closed are hung onto, pending garbage
            collection. By suggesting garbage collection, the next time, the
            renameTo() usually (but not always) works.
            ----------------------------------------------- */
            for (int i=0; i<20; i++)
               {
               if (super.renameTo(pNewFile))
                  {
                  return true;
                  }
               System.gc();
               Util.sleep(50);
               }
            return false;
            }
         }

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      File x = new File("file.x"); // existing file same as File y
      File y = new File("file.x"); // existing file same as File x
      File z = new File("new.x"); // new file name for non-existing file

      // do I/O ops with File y

      y = null;

      if (x.renameTo(z)) System.out.println("success");
      else System.out.println("failure");



      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      should always report success and rename the file.
      ACTUAL -
      usually reports "failure" and does not rename the file.


      ERROR MESSAGES/STACK TRACES THAT OCCUR :
      None; unfortunately, File.renameTo() doesn't throw an exception, it just returns "false" when it fails.

      REPRODUCIBILITY :
      This bug can be reproduced often.

      ---------- BEGIN SOURCE ----------
      File x = new File("file.x"); // existing file same as File y
      File y = new File("file.x"); // existing file same as File x
      File z = new File("new.x"); // new file name for non-existing file

      // do I/O ops with File y

      y = null;


      ---------- END SOURCE ----------

      CUSTOMER SUBMITTED WORKAROUND :
      public class XFile extends File
         {

         /*
         ==============================================================
         ============================================================== *//**
         This method is a cover for File.renameTo(). The motivation for this
         cover method is that with this new version of Java (1.5.0), rename (and
         other file methods) sometimes don't work on the first try. This seems to
         be because file objects that have been closed are hung onto, pending
         garbage collection.

         @return
            true if and only if the renaming succeeded; false otherwise

         @param
            pNewFile is a File object containing the new name for the file.
         *//*
         -------------------------------------------------------------- */
         public boolean renameTo(File pNewFile)
            {
            /*
            ===============================================
            HACK - I should just be able to call renameTo() here and return its
            result. In fact, I used to do just that and this method always worked
            fine. Now with this new version of Java (1.5.0), rename (and other
            file methods) sometimes don't work on the first try. This is because
            file objects that have been closed are hung onto, pending garbage
            collection. By suggesting garbage collection, the next time, the
            renameTo() usually (but not always) works.
            ----------------------------------------------- */
            for (int i=0; i<20; i++)
               {
               if (super.renameTo(pNewFile))
                  {
                  return true;
                  }
               System.gc();
               Util.sleep(50);
               }
            return false;
            }
         }
      ###@###.### 2005-1-02 13:20:06 GMT

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              • Assignee:
                alanb Alan Bateman
                Reporter:
                ndcosta Nelson Dcosta (Inactive)
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