Friday, January 11, 2013

EXECUTE COMMAND’S AND APPLICATION IN APPLET THROUGH SYSTEM CALL


Some time it’s become very difficult to access any application or to execute commands in java applet. And many of us don’t know how to do this, so I am going to explain how to access or execute any command in Applet. Consider the following program, when you execute it, it will directly open a Firefox application, and you can also replace it with any commands of Linux or windows.

import java.awt.*;                                                              // Packages
import java.io.IOException;
import java.io.InputStream.*;
import java.awt.event.*;
import java.applet.*;
public class Firefox extends Applet
{
            String command="firefox";
   public void init()
   {
              // Construct the button
                  Button browser = new Button("Browser");
             // add the button to the layout
                 this.add(browser);
             // specify that action events sent by this
                   browser.addActionListener(new BeepAction());
              try
             {
                        Runtime.getRuntime().exec(command);
             }
              catch (IOException e)
             {
                        e.printStackTrace();
             }
      }
}

If you don’t have any idea about Applet programming then just follow the following link and just downloads PDF files as per your requirement.

Every Java application has a single instance of class Runtime that allows the application to interface with the environment in which the application is running. The current runtime can be obtained from the getRuntime method.
Prints the throwable and the throwable’s call trace. The call stack shows the sequence of method calls that brought you to the point at which exception was thrown.

The first version prints to standard error, the second prints to a stream of your choice. If you’re working under Windows, you can’t redirect standard error so you might want to use the second version and send the results to System.out; that way the output can be redirected any way you want.