implementation of a "FileListener"
I would like to know if someone has developped a kind of Filelistener.
Goal :
is to do something if a file has changed...
Constraints:
mustn't monopised the CPU
Else i have done a thread that is looking for the size of a file. But the problem is that it take near 100% of the CPU. Same with some Wait or Sleep Methods...
If someone have any Idea... else It could be a very good think to implement it and include it in next version of th JDK.
Thx
[505 byte] By [
befa] at [2007-9-26 2:07:36]
eg?
import java.io.*;
import java.util.*;
public class FileTail extends Observable
{
private long sleepTime = 1000;
private Thread clockThread = null;
private volatile boolean noStopRequested = true;
private Runnable r = null;
private File f = null;
private long lastModified = 0;
private FileTail( String fileName )
{
f = new File( fileName );
try
{
r = new Runnable()
{
public void run()
{
try
{
runWork();
}
catch( Exception e )
{
e.printStackTrace();
}
}
};
}
catch( Exception e )
{
e.printStackTrace();
}
clockThread = new Thread( r );
clockThread.start();
}
public static void main( String[] args )
{
FileTail agt = new FileTail( args[ 0 ] );
}
public void process() {
try
{
long tn = f.lastModified();
if( 0 < ( tn - lastModified ) )
{
lastModified = tn;
System.out.println( "m: " + f.getName() );
}
}
catch( Exception e )
{
e.printStackTrace();
}
}
private void runWork() {
while( noStopRequested ) {
try {
this.process();
Thread.sleep( sleepTime );
} catch( Exception e ) {
e.printStackTrace();
}
}
}
public Object getValue()
{
return null;
}
public void stopRequest()
{
noStopRequested = false;
clockThread.interrupt();
}
public void startRequest()
{
noStopRequested = true;
clockThread.interrupt();
}
}
