PK82150: JAVA REPORTS INCORRECT FILE LENGTHS FOR FILES OVER 2GB IN SIZE IN 31BIT MODE.

APAR status

• Closed as program error.

Error description

• The java.io.File.length() method returns the length of the file
  denoted by the File class instance. The return type for this API
  method is "long" which is a 64bit value in the Java language.
  
  The length method (via the UnixFileSystem.getLength method)
  makes a call to the underlying OS's "stat" function which is not
  64bit aware when compiled in 31bit mode.
  
  This APAR will address the use of the _LARGE_FILES FTM on 31bit
  z/OS builds to ensure that java.io.File functions return the
  correct 64bit values according to the Java specification.
  
  See Also: APAR IZ34802 for FileChannel
  
  KEYWORDS:
  File Overflow length size HFS zFS
  
  
  VERIFICATION STEPS:
  If a file exists in the file system with a size of 2GB or
  greater, the following code snippet will report and incorrect
  value. The number will be negative for sizes 2GB to 4GB. It will
  be an incorrect positive value for 4GB and above. The value
  being returned is an "int" instead of a "long"
  

Local fix

• Use a 64bit version of the Java Virtual Machine to deal with
  File Sizes in their correct 64bit representations.
  

Problem summary

• File.length() uses stat() to get the the file size which is
  defined as 31 bit in stat structure and can handle only 2GB size
  in 31 bit addressing zOS system.
  

Problem conclusion

• This defect will be fixed in:
  5.0.0 SR10
  .
  In 31 bit addressing zOS, this problem can be resolved using a
  Feature Test Macro _LARGE_FILES.
  This feature test macro enables certain functions to operate on
  HFS files that are larger than 2 gigabytes in size. When this
  feature test macro is selected it must be used in conjunction
  with the compiler option, LANGLVL(LONGLONG) to activate the long
  long data type.
  This function will be activated to operate on HFS files of all
  sizes by expanding appropriate offset and file size values to a
  64 bit value.
  .
  To obtain the fix:
  Install build 20090516 or later
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA 5 Z/OS 31

• Fixed component ID

  620500105

Applicable component levels

• R500 PSN

     UP