Question

OK. Simple question. Maybe not so simple answer, though:

I have a file I downloaded in Java, and I know that it’s a text file. Is there any way that I can use Java to open that text file in whatever the default text editor is? It has to work for all OS’s, otherwise I would just make it open with Notepad.

:\ I guess that if there’s no way to do this I could use JOptionPane and show the contents of the text file…

Answer 1

You can do that with:

java.awt.Desktop.getDesktop().edit(file);

This links to the tutorial article on java.awt.Desktop:

Java™ Standard Edition version 6
narrows the gap between performance
and integration of native applications
and Java applications. Along with the
new system tray functionality, splash
screen support, and enhanced printing
for JTables , Java SE version 6
provides the Desktop API
(java.awt.Desktop) API, which allows
Java applications to interact with
default applications associated with
specific file types on the host
platform.

It is cross-platform, but may not be supported everywhere. There is a method you can call to check whether the Desktop API is available, called isDesktopSupported (see the link for more explanation). I was using this API the other day to open PDFs in a Swing client.

Unfortunately there is a known bug affecting some Windows platforms (XP and 2003) that will crash the JVM. Write once, debug everywhere, as usual. Anyway, for Windows there is a nice workaround which still uses the user’s preferred application:

if (System.getProperty("os.name").toLowerCase().contains("windows")) {
  String cmd = "rundll32 url.dll,FileProtocolHandler " + file.getCanonicalPath();
  Runtime.getRuntime().exec(cmd);
} 
else {
  Desktop.getDesktop().edit(file);
}