Java and using named pipes

[Ramses de Norre]

Yesterday I was shown the concept of named pipes (also called fifos), but it seems that java can't handle them?
I made a fifo in my home directory with mkfifo clip and wrote a little script to link a purpose to it:
#!/bin/bash

LOC=/home/ramses/clip

if [ -p $LOC ]
then
while(true)
do
xclip -in < $LOC > out
done
else
echo "$LOC doesn't exist or is no named pipe, exiting"
exit 1
fi

This all works perfect, but now the problem:
When I write this in java:
PrintWriter pW=new PrintWriter(new BufferedOutputStream(new FileOutputStream(new File("/home/ramses/clip")))); the application just hangs on that line... No extensive cpu load, no exceptions, just nothing...
If I create just an OutputStream it works, but not with a PrintWriter.
The same line does work on a regular file.

Anyone who can explain this and maybe knows a workaround?
And the file permissions are set to 777 so that isn't the problem, I can also perfectly write to it from the command line.

[Ramses de Norre]

Someone?

[Ragazzo]

This works for me:

mkfifo pipe
cat < pipe



import java.io.*;

class Test {
public static void main(String[] args) throws Exception {
PrintWriter pw = new PrintWriter(new BufferedOutputStream(new FileOutputStream("/home/jukka/pipe")));
pw.println("hello");
pw.close();
}
}


And then java Test in another terminal.

Edit: Don't forget to flush the stream

[Ramses de Norre]

Strange, I didn't try for a few days and now suddenly it does work...
I activated the fifo with
while(true); do xclip -in < clip > out; done;
And wrote this little java app (it's just a test, I know it isn't good:p)

package ogpTest;

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;

import javax.swing.JOptionPane;

public class Clipboard
{
public static void main(String[] args) throws IOException
{
String s;
PrintWriter pW=new PrintWriter(new BufferedOutputStream(new FileOutputStream("/home/ramses/clip")));

while (true)
{
s = JOptionPane.showInputDialog("Give string to put on clipboard");
pW.print(s);
pW.flush();
}
}
}


It doesn't work as it should though... The things pasted on the clipboard aren't always altered, I guess I'll need to look a bit deeper into this.

[beligum]

Use printLN instead of print, the newline is important.