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Solved

to make read-only

Posted on 1998-08-06
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269 Views
Last Modified: 2010-04-16
How do write a Java program to  change the attrib of any text file to Read-Only. I tried using File Permission and File class, but i am not able to do that. Could any body suggest.. please... I use jdk1.2beta3 on Win95.
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Question by:hvhemant
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Author Comment

by:hvhemant
ID: 1231476
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awilkins earned 10 total points
ID: 1231477
Create a new File object representing the text file.  Then call setReadOnly().  For example,

File myFile = new File ("myFile.txt");
myFile.setReadOnly();

If you wish to do this for multiple files, create a new FilenameFilter that only accepts text files and call
  myDir.list(myFilenameFilter);
where myDir is the directory in which your text files reside and myFilenameFilter is your FileName Filter that only accepts text files.  Code for this filter could be as follows:

import java.io.FilenameFilter;
public class myFilenameFilter implements FilenameFilter
{
  public boolean accept(File dir, String name)
  {
    return (name.endsWith(".txt"));
  }
}

This file will accept only files with the extension ".txt", rejecting all others.
Hope this helps somewhat --
              Alexander Wilkins
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Author Comment

by:hvhemant
ID: 1231478
awilkins,

thanks for the reply.
setReadOnly() method is available in Permissions class of java.security and not in File class. I tried your sample, it comes out with an error saying method not found in java.io. Even I tried using Permissions  and FilePermission classes, but I am not able to set.....

here is a sample code what i tried for your ref....

File ff = new File("test.txt");
Permissions p = new Permissions();
FilePermission fp = new FilePermission("test.txt", "read");
p.add(fp);
p.setReadOnly();
boolean rd = p.isReadOnly();
System.out.println(rd);

in above sample rd(boolean) comes out with true, but it is not setting  the file to readonly.
please suggest to solve this.
I need also how to set  archive bit of a file to on/off.

bye
      
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Expert Comment

by:awilkins
ID: 1231479
Sorry -- I just checked and the java.io.File.setReadOnly() method was first implemented in jdk 1.2.  What compiler and version are you using? An IDE?
  -- Alexander Wilkins
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Author Comment

by:hvhemant
ID: 1231480
Alexander,
thanks for the reply.
I use windows simple text editor for coding and compile  on command prompt. OS is Windows 95. JVM (javac.exe) is jdk1.2beta3.

thank you and bye.
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Expert Comment

by:awilkins
ID: 1231481
I'm using 1.2beta4, WinNT, also with a text editor & the command prompt.  I would think that java.io.File.setReadOnly() would also be present in 1.2beta3, but maybe not.  If it isn't, you might consider upgrading to the next beta version.
  A workaround might be to set the readOnly and archive attributes from a batch file.  The command to set these attributes from the command line is
                   attrib [+r|-r] [+a|-a] [+s|-s] [+h|-h][[drive:][path] filename]
where something like
                  attrib +r -a myFile.txt
would make myFile.txt read-only but remove its archive attribute.  Also, java does not seem to have any way of reading/setting the archive setting of a file, probably because it is windows-specific.

  Hope this is helps some --
                   Alexander Wilkins
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