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Detect the browser/JVM type (deprecated)Tag(s): Environment DEPRECATED


This HowTo is obsolete. Check this one instead : Detect browser type from an Applet
One way is to instanciate a known browser-specific method and catch the Exception if not found 
import java.applet.*;

public class BrowserDetector extends Applet {
  public void init() {
    if ( isNetscape() )
       System.out.println("This browser is a Netscape Browser.");
    if ( isMicrosoft() )
       System.out.println("This browser is a Microsoft Browser.");
    }

  public static boolean isNetscape() {
    try {
      Class.forName("netscape.applet.MozillaAppletContext");
      }
    catch (ClassNotFoundException e) {
      System.out.println("This browser is not a Netscape Browser.");
      return false;
      }
    return true;
    }

  public static boolean isMicrosoft() {
    try {
      Class.forName("com.ms.applet.GenericAppletContext");
      }
    catch (ClassNotFoundException e) {
      System.out.println("This browser is not a Microsoft Browser.");
      return false;
      }
    return true;
    }
}
Or by examining the string representation of the getAppletContext() method 
String theBrowser = "APPLICATION";
String appletContext = getAppletContext().toString();
if (appletContext.startsWith("sun.applet.AppletViewer"))
   theBrowser = "APPLETVIEWER";
else if (appletContext.startsWith("netscape.applet."))
   theBrowser = "NETSCAPE";
else if (appletContext.startsWith("com.ms.applet."))
   theBrowser = "MICROSOFT";
else if (appletContext.startsWith("sunw.hotjava.tags.TagAppletPanel"))
   theBrowser = "HOTJAVA";
else if (appletContext.startsWith( "sun.plugin.navig.win32.AppletPlugin"))
   theBrowser = "NETSCAPEPLUGIN";
else if (appletContext.startsWith( "sun.plugin.ocx.ActiveXApplet"))
   theBrowser = "MICROSOFTPLUGIN;
else if (appletContext.startsWith
      ( "sun.plugin.viewer.context.IExplorerAppletContext")
   theBrowser = "MICROSOFTPLUGINJRE1.4;
For an application, by looking at the string representation of the getDefaultToolkit() method, we detect the JVM type 
String theJVM = "";
String toolkit = Toolkit.getDefaultToolkit().toString();

if (theBrowser.equals("APPLICATION") {
   if (toolkit.startsWith( "sun.awt.windows.WToolkit"))
      theJVM = "JAVA";
   else if (toolkit.startsWith( "com.ms.awt.WToolkit"))
      theJVM = "JVIEW";
   }
For example, our MyApplet.class exists in three versions. One is using Microsoft-specific classes, the other is a JDK1.1 applet and finally a version for JDK102-only browser. The idea is to put all the required classes in an ARCHIVE file. By using a javascript entities, we decide which archive to use. During layout time, the javascript entity is remplaced by the right archive name. 
<HTML></HTML><HEAD>
<SCRIPT>
 function isBrowser(b,v) {
    browserOk = false;
    versionOk = false;
    browserOk = (navigator.appName.indexOf(b) != -1);
    versionOk = (v <= parseInt(navigator.appVersion));
    return browserOk && versionOk;
   }

 archiveToBeUsed = "java102.jar";

 if (isBrowser("Microsoft", 4)) {
    archiveToBeUsed = "ie4.jar";
    }
 else {
    if isBrowser("Netscape", 4) {
       archiveToBeUsed = "n4.jar";
       }
    }


 </SCRIPT></HEAD><BODY>
 <APPLET CODE ="MyApplet.class"
         HEIGHT=100
         WIDTH=400
         ARCHIVE=&{archiveToBeUsed}; >
 </APPLET>
 </BODY></HTML>
NOTE: You may need to use the document.write() method to generate the right APPLET tag instead of a the Javascript entity to be compatible with Netscape and IE.