Start the default browser from an application

Start the default browser from an application
In this snippet, we initialize a Listbox from a file containing some URLs. When we double click an item, the default browser is started with the selected HTML page as parameter. This example is Windows oriented since I have used the start command which supports the file association.

[urlList.txt]
http://www.rgagnon.com/javadetails/java-0001.html|JAVA How-to 1
http://www.rgagnon.com/javadetails/java-0002.html|JAVA How-to 2
http://www.rgagnon.com/javadetails/java-0003.html|JAVA How-to 3
http://www.rgagnon.com/javadetails/java-0004.html|JAVA How-to 4
http://www.rgagnon.com/javadetails/java-0005.htmL|JAVA How-to 5

[StartBrowser.java]
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;

public class StartBrowser {
public static void main(String s[]) {
AFrame f = new AFrame();
}
}

class AFrame extends Frame implements ActionListener {
List lbx;
String url[] = new String[50];

public AFrame() {
// dispaly setup
setTitle("URL selection");
setSize(400,400);
lbx = new List();
add(lbx);
initLbx();
// action on listbox double click
lbx.addActionListener(this);
// to close the Frame
addWindowListener
(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}
);
setVisible(true);
}

public void actionPerformed (ActionEvent ae) {
String theUrl = url[lbx.getSelectedIndex()];
// start the default browser (Win95 platform)
// on listbox double click

String cmdLine = "start " + theUrl;
// on NT, you need to start cmd.exe because start is not
// an external command but internal, you need to start the
// command interpreter
// String cmdLine = "cmd.exe /c " + cmdLine;
try {
Process p = Runtime.getRuntime().exec(cmdLine);
}
catch (Exception e) {
e.printStackTrace();
}
}

public void initLbx() {
int i = 0;
try {
String aLine = "";
BufferedReader in
= new BufferedReader(new FileReader("urlList.txt"));
while(null != (aLine = in.readLine())) {
java.util.StringTokenizer st =
new java.util.StringTokenizer(aLine, "|");
url[i++] = st.nextToken();
lbx.addItem(st.nextToken());
// lbx.add(st.nextToken()); in JDK1.2
}
}
catch(Exception e) {
e.printStackTrace();
}
}
}
Another way on Windows platform to start the default browser is ;
Runtime.getRuntime().exec
("rundll32 url.dll,FileProtocolHandler " + theUrl);

You may have difficulty to open a URL ending with .htm. All you need is to replace the last m with %6D, like

rundll32 url.dll,FileProtocolHandler http://www.rgagnon.com/howto.htm

for

rundll32 url.dll,FileProtocolHandler http://www.rgagnon.com/howto.ht%6D


--------------------------------------------------------------------------------
JDK1.6 has java.awt.Desktop.open(File)
See http://java.sun.com/javase/6/docs/api/java/awt/Desktop.html

JDIC provides the equivalent API for 1.4 and later.

See https://jdic.dev.java.net

try {
Desktop.browse(new URL("http://www.rgagnon.com");

}
catch (MalformedURLException e1) {
e1.printStackTrace();
}
catch (DesktopException e2) {
e2.printStackTrace();
}