Take control of the DOM, Part 3

		
	import java.io.*;
import java.awt.*;
import java.awt.print.*;
import java.net.*;
import java.security.*;
import org.w3c.dom.*;
import org.w3c.dom.html.*;
import org.w3c.dom.events.*;
import com.ibm.weblet.*;
// Demonstrate security-sensitive operations in weblets
public class SecurityOps implements Weblet {
     private WebletContext m_engine;
     HTMLDocument doc;
     public void init( WebletContext engine ){
       m_engine = engine;
       doc = m_engine.getOwnerDocument();
     }
     //              convenience for putting output to document divisions
     void putOut(String divisionName, String message){
       Element division = doc.getElementById(divisionName);
       division.appendChild( doc.createTextNode(message) );
       division.appendChild( doc.createElement("br") );
     }
     public void start() {
       // ------------------------------------------ Read a local file
       try {
         String fn = "SecurityOps.java";
         putOut("readFileDiv", "Attempt to read local file...");
         File f = new File(fn);
         DataInputStream dis;
         if (f.exists()) {
           dis = new DataInputStream(new BufferedInputStream(new 
FileInputStream(fn),128));
           putOut( "readFileDiv", "First line is: " + dis.readLine() );
         } else {
           putOut( "readFileDiv", "But... " + fn + " doesn't exist!");
         }
       } catch (Exception e) {
         putOut( "readFileDiv", e.getClass().getName() + ": " + 
e.getMessage() );
       }
       // ----------------------------------------- Read visible properties
       try {
         putOut("propertiesDiv", "OS: " + System.getProperty("os.name") );
       } catch (Exception e) {
         putOut("propertiesDiv", e.getClass().getName() +": "+ e.getMessage());
       }
       // ----------------------------------------- Read hidden properties
       try {
         putOut("hiddenDiv", "User Name: " + System.getProperty("user.name") );
       } catch (Exception e) {
         putOut("hiddenDiv", e.getClass().getName() +": "+ e.getMessage());
       }
       // ----------------------------------- Get the current Security Policy
       try {
         putOut("policyDiv", "Attempting Policy.getPolicy()...");
         Policy p = Policy.getPolicy();
         putOut( "policyDiv", "Got: "+ p.toString() );
       } catch (Exception e) {
         putOut("policyDiv", e.getClass().getName() +": "+ e.getMessage());
       }
       // --------------------------------------------- Shut down the JVM
       try {
         putOut("killDiv", "Attempt System.exit(0)...");
         System.exit(0);
       } catch (Exception e) {
         putOut("killDiv", e.getClass().getName() + ": "+ e.getMessage());
       }
       // ---------------------------------------------- Create a Print Job
       try {
         putOut("printDiv", "Print from a Weblet...");
         PrinterJob job = PrinterJob.getPrinterJob();
         job.setPrintable(new Printable() {
                            public int print(Graphics g, PageFormat 
format, int index)
                            throws PrinterException {
                              if (index>0) return NO_SUCH_PAGE; // 
prints one page
                              else {
                                g.setColor(Color.black);
                                int ascent = 
g.getFontMetrics(g.getFont()).getAscent();
                                g.drawString("Hello, Weblet!",
                                            (int)format.getImageableX(),
 
(int)format.getImageableY() + ascent);
                                return PAGE_EXISTS;
                              }
                            }
                          }
                         );
         job.print();
         putOut("printDiv", "...printing succeeded.");
       } catch (Exception e) {
         putOut("printDiv", e.getClass().getName() +": "+ e.getMessage());
         e.printStackTrace(System.err);
       }
       // ------------------------------------------ Connect to the host
       try {
         String myUrl = doc.getURL();
         String myHost =  new URL(myUrl).getHost();
         putOut("hostDiv", "Connect to host: " + myHost + "...");
         Socket sHome = new Socket(myHost, 80, true);
         sHome.close();
         putOut("hostDiv", "  ...socket created & closed.");
       } catch (Exception e) {
         putOut("hostDiv",
                e.getClass().getName() +": " + e.getMessage() );
       }
       // ----------------------------------------Connect to www.ibm.com
       try {
         String server =  "www.ibm.com";
         putOut("serverDiv", "Connect to host: " + server + "...");
         Socket sHome = new Socket(server, 80, true);
         sHome.close();
         putOut("serverDiv", "  ...socket created & closed.");
       } catch (Exception e) {
         putOut("serverDiv",
                e.getClass().getName() +": " + e.getMessage() );
       }
     }
     public void stop(){}
     public void destroy(){}
}  // class SecurityOps