How to tell if a file is being used by another process?

Question

Thanks to nrlz for helping me with my last question http://forum.java.sun.com/thread.jsp?forum=31&thread=387999&tstart=15&trange=15 i have been able to make my virtual folder containing folders :) sort of a tounge twister :)
However i have had to put in a 1 second delay before running the script after i create it otherwise the script will fail as it thinks the file is still being used by the java program.
I wish to know how to test for wether a file is currently locked by a process (with out trying to create a File() instance in a try/catch block as this would lock the file again :/ )
the program is below.
If you are using win98 you may need to change:
Runtime.getRuntime().exec("c:\\winnt\\system32\\wscript.exe \"createShorcut.vbs\"");
to
Runtime.getRuntime().exec("c:\\windows\\system32\\wscript.exe \"createShorcut.vbs\"");
you will need a file called directories.ini with the following format:
<directory that will hold the shortcuts>
<directory 1>
<directory 2>
<directory n>
END
example
--->file start<---
c:\root
c:\
d:\
f:\apps\
g:\games\
END
--->file end<----
import java.io.*;
class winVirtualFolder
     public static void main (String args[]) throws IOException, InterruptedException
           File inFile = new File("directories.ini");
         FileReader fileReader = new FileReader(inFile);
         BufferedReader bufReader = new BufferedReader(fileReader);
         String str="";
               String home="";
               winVirtualFolder wVF=new winVirtualFolder();
         home= bufReader.readLine();
               str=bufReader.readLine();
               System.out.println("HOME DIR: "+home);
               while (!str.equals("*END*"))
                    System.out.println("***STR: "+str);
                    wVF.createShortcuts(str,home);
                    str=bufReader.readLine();
     void createShortcuts(String path,String home) throws IOException, InterruptedException
          File directory= new File(path);
          String[] listing =directory.list();
          File[] fileListing =directory.listFiles();
          String[] directories= new String[listing.length];
          for (int i=0;i<listing.length;i++)
               System.out.print(listing);
               if (fileListing[i].isDirectory())
                    System.out.println(" DIRECTORY");
          File outFile = new File("createShorcut.vbs");
          FileWriter fileWriter = new FileWriter(outFile);
               BufferedWriter bufWriter = new BufferedWriter(fileWriter);
                    bufWriter.write("set WshShell = WScript.CreateObject(\"WScript.Shell\")\r\n");
                    bufWriter.write("set oShellLink = WshShell.CreateShortcut(\""+home+""+listing[i]+".lnk\")\r\n");
                    bufWriter.write("oShellLink.TargetPath = \""+path+""+listing[i]+"\\\"\r\n");
                    bufWriter.write("oShellLink.Description = \""+listing[i]+"\\\"\r\n");
                    bufWriter.write("oShellLink.Save\r\n");
          bufWriter.close();
                    sleep(1000);
                    Runtime.getRuntime().exec("c:\\winnt\\system32\\wscript.exe \"createShorcut.vbs\"");
               else System.out.println("");
     void sleep (long time)
          long waitValue=System.currentTimeMillis()+time;
          while (System.currentTimeMillis()<waitValue){}

Answer 1

I have over come my problem by creating a seperate script for each shortcut first and then running the scripts later. This does mean that there needs to be space for the temporary script files... but since each of those are under 1K each i do not suppose that it is much of an issue. It has however remakably increased performance by over 100 fold!
here is the code if anyone is interested:
import java.io.*;
import java.util.*;
class winVirtualFolder
     public static void main (String args[]) throws IOException
           File inFile = new File("directories.ini");
         FileReader fileReader = new FileReader(inFile);
         BufferedReader bufReader = new BufferedReader(fileReader);
         String str="";
               String home="";
               int count=0;
               winVirtualFolder wVF=new winVirtualFolder();
         home= bufReader.readLine();
               str=bufReader.readLine();
               System.out.println("Home Directory: "+home);
               Vector createdDirectories = new Vector();
               File directory= new File(home);
               String[] listing =directory.list();
               for (int i=0;i<listing.length;i++)
                    if (wVF.isAlink(listing))
                         createdDirectories.add(listing[i].substring(0,listing[i].length()-4));
                         count++;
               int startCount=count;
               while (!str.equals("*END*"))
                    System.out.println("Creating shortcuts scripts of directories from "+str);
                    count=wVF.createScripts(str,home,createdDirectories,count);
                    str=bufReader.readLine();
               System.out.print("Running Scripts");          
               wVF.runScripts(startCount,count,home);
               int dirCount=0;
               File file;
               while (dirCount<count-1)
                    dirCount=0;
                    String str1;
                    for (int i=0;i<createdDirectories.size();i++)
                         str1=(String) createdDirectories.get(i);
                         file = new File(home+""+str1+".lnk");
                         if (file.exists()) dirCount++;
                    System.out.print(".");
                    wVF.sleep(100);
               System.out.println("Done!");
               System.out.println("Deleting Scripts");
               wVF.deleteScripts(startCount,count,home);
     int createScripts(String path,String home,Vector createdDirectories, int count) throws IOException
          File directory= new File(path);
          String[] listing =directory.list();
          File[] fileListing =directory.listFiles();
          String[] directories= new String[listing.length];
          for (int i=0;i<listing.length;i++)
               if (fileListing[i].isDirectory())
                    int no=0;
                    String number="";
                    while(exists(listing[i]+""+number,createdDirectories))
                         no++;
                         number="-"+no;
                    createdDirectories.add(listing[i]+""+number);
                    File outFile = new File(home+"createShorcut"+count+".vbs");
          FileWriter fileWriter = new FileWriter(outFile);
               BufferedWriter bufWriter = new BufferedWriter(fileWriter);
                    bufWriter.write("set WshShell = WScript.CreateObject(\"WScript.Shell\")\r\n");
                    bufWriter.write("set oShellLink = WshShell.CreateShortcut(\""+home+""+listing[i]+""+number+".lnk\")\r\n");
                    bufWriter.write("oShellLink.TargetPath = \""+path+""+listing[i]+"\\\"\r\n");
                    bufWriter.write("oShellLink.Description = \""+listing[i]+"\\\"\r\n");
                    bufWriter.write("oShellLink.Save\r\n");
          bufWriter.close();
                    count++;
          return count;
     void runScripts(int startCount,int count,String home) throws IOException
          for (int i=startCount;i<count;i++)
               Runtime.getRuntime().exec("c:\\winnt\\system32\\wscript.exe \""+home+"createShorcut"+i+".vbs\"");
     void deleteScripts(int startCount,int count,String home) throws IOException
          for (int i=startCount;i<count;i++)
               File outFile = new File(home+"createShorcut"+i+".vbs");
               outFile.delete();
     void sleep (long time)
          long waitValue=System.currentTimeMillis()+time;
          while (System.currentTimeMillis()<waitValue){}
     boolean exists(String str,Vector createdDirectories)
          for (int i=0;i<createdDirectories.size();i++)
               if (str.equals((String) createdDirectories.get(i))) return true;
          return false;
     boolean isAlink(String str)
          if (str.endsWith(".lnk"))
               return true;
          return false;