package puzzel;
/* Copyright (C) 2002 */
/* This class was found at: [url]http://www.javaworld.com[/url] */
import java.io.IOException;
/**
* A simple, static class to display a URL in the system browser.
*
* Under Unix, the system browser is hard-coded to be 'netscape'.
* Netscape must be in your PATH for this to work. This has been
* tested with the following platforms: AIX, HP-UX and Solaris.
*
* Under Windows, this will bring up the default browser under windows,
* usually either Netscape or Microsoft IE. The default browser is
* determined by the OS. This has been tested under Windows 95/98/NT.
*
* Examples:
*
BrowserControl.displayURL("http://www.javaworld.com")
*
BrowserControl.displayURL("file://c:\\docs\\index.html")
*
BrowserContorl.displayURL("file:///user/joe/index.html");
*
* Note - you must include the url type -- either "http://" or
* "file://".
*/
public class Link {
// Used to identify the windows platform.
private static final String WIN_ID = "Windows";
// The default system browser under windows.
private static final String WIN_PATH = "rundll32";
// The flag to display a url.
private static final String WIN_FLAG = "url.dll,FileProtocolHandler";
// The default browser under unix.
private static final String UNIX_PATH = "netscape";
// The flag to display a url.
private static final String UNIX_FLAG = "-remote openURL";
/**
* Display a file in the system browser. If you want to display a
* file, you must include the absolute path name.
*
* @param url the file's url (the url must start with either "http://"
or
* "file://").
*/
public static void displayURL(String url) {
boolean windows = isWindowsPlatform();
String cmd = null;
try {
if (windows) {
// cmd = 'rundll32 url.dll,FileProtocolHandler http://...'
cmd = WIN_PATH + " " + WIN_FLAG + " " + url;
Runtime.getRuntime().exec(cmd);
} else {
// Under Unix, Netscape has to be running for the "-remote"
// command to work. So, we try sending the command and
// check for an exit value. If the exit command is 0,
// it worked, otherwise we need to start the browser.
// cmd = 'netscape -remote openURL([url]http://www.javaworld.com[/url])'
cmd = UNIX_PATH + ' ' + UNIX_FLAG + '(' + url + ')';
Process p = Runtime.getRuntime().exec(cmd);
try {
// wait for exit code -- if it's 0, command worked,
// otherwise we need to start the browser up.
int exitCode = p.waitFor();
if (exitCode != 0) {
// Command failed, start up the browser
// cmd = 'netscape http://www.javaworld.com'
cmd = UNIX_PATH + " " + url;
p = Runtime.getRuntime().exec(cmd);
}
} catch (InterruptedException x) {
System.err.println("Error bringing up browser, cmd='" + cmd + "'");
System.err.println("Caught: " + x);
}
}
} catch (IOException x) {
// couldn't exec browser
System.err.println("Could not invoke browser, command=" + cmd);
System.err.println("Caught: " + x);
}
}
/**
* Try to determine whether this application is running under Windows
* or some other platform by examing the "os.name" property.
*
* @return true if this application is running under a Windows OS
*/
public static boolean isWindowsPlatform() {
boolean retVal = false;
String os = System.getProperty("os.name");
if (os != null && os.startsWith(WIN_ID)) {
retVal = true;
} else {
retVal = false;
}
return retVal;
}
}
