import java.applet.*;
import java.util.*;
import java.io.*;
import java.net.*;
import netscape.security.PrivilegeManager;

public class UserInfoApplet extends Applet {
  // URL where this applet will be hosted
  public final String urlSource="http://www.javaworld.com/jw-10-1998/apptowin32/";
  public final String dllFileName="userinfo.dll";
  String dllDest;
  public final String jniClassName="UserInfo.class";
 // UserInfo info;    

  public void installDLL ( ) {
     try {
     PrivilegeManager.enablePrivilege("UniversalFileAccess");
     } catch (Exception e) { 
     System.out.println ("Can't enable file Privilege!!!"); 
     e.printStackTrace();
     }

     dllDest = findTempDir() + "userinfo.dll";
     System.out.println("Copying " + urlSource + dllFileName + 
        " to " + dllDest + " . . .  " );
     copyURL ( urlSource + dllFileName, dllDest );
  }

  public void installJniWrapperClass ( ) {
     try {
     PrivilegeManager.enablePrivilege("UniversalFileAccess");
     } catch (Exception e) { 
     System.out.println ("Can't enable file Privilege!!!"); 
     e.printStackTrace();
     } 
     System.out.println ("copying " + urlSource+jniClassName + " to "
     +  parseClassPath()+jniClassName);

     copyURL (urlSource+jniClassName, parseClassPath()+jniClassName);
 
  }
  
  public void loadLibrary () {
     try {
     System.out.println("asking for link privilege . . . ");
     PrivilegeManager.enablePrivilege("UniversalLinkAccess");
     } catch (Exception e) { 
     System.out.println ("Can't enable link Privilege!!!"); 
     e.printStackTrace();
     }

     try {
     System.load ( dllDest );
     System.out.println ("library loaded . . .");
     }

     catch (Exception e) { 
     System.out.println ("Can't load library!!!"); 
     e.printStackTrace();
     }
     catch (Error err) {
     System.out.println ("ERROR:  Can't load library!!!"); 
     err.printStackTrace();
     }
     System.out.println ("Creating instance of JNI wrapper class from hard drive");
    // info = new UserInfo ();
  }

  public String getUserName() {
     String name;
     // we can't reference UserInfo class until AFTER it exists on
     // local classpath!
     UserInfo info = new UserInfo();
     try {
     PrivilegeManager.enablePrivilege("UniversalLinkAccess");
     } catch (Exception e) { 
     System.out.println ("Can't enable link Privilege!!!"); 
     e.printStackTrace();
     }

     try { 
        name =  info.getUserName(); 
     } catch (Error er) {
        er.printStackTrace();
        return ("Java Error on getUserName!") ;
     }
     return name;
  }

  public String getComputerName() {
     String name;

     // we can't reference UserInfo class until AFTER it exists on
     // local classpath!
     UserInfo info = new UserInfo();

     try {
     PrivilegeManager.enablePrivilege("UniversalLinkAccess");
     } catch (Exception e) { 
     System.out.println ("Can't enable link Privilege!!!"); 
     e.printStackTrace();
     }

     try { 
       name =  info.getComputerName(); 
     } catch (Error e) {
        e.printStackTrace();
        return "Java Exception on getComputerName!";
     }
     return name;
  }

  private String parseClassPath () {
   String destString = "";

   try {
     PrivilegeManager.enablePrivilege("UniversalPropertyRead");
   } catch (Exception e) { 
   System.out.println ("Can't enable file Privilege!!!"); 
     e.printStackTrace();
   }

   String classPath = System.getProperty("java.class.path");
   String pathSeparator = System.getProperty("path.separator");
   String fileSeparator = System.getProperty("file.separator");
   
   // test search string--debug
   String searchString = "java" + fileSeparator + "classes";
   
   StringTokenizer sTok  = new StringTokenizer ( classPath, pathSeparator);

   // find dir ending with "java/classes" or "java\classes" depending on sys
   while (sTok.hasMoreElements()) {
      destString = sTok.nextToken() ;
      if ( destString.endsWith(searchString) )  break;
   }
    return (destString + fileSeparator); 
  }

   private String findTempDir () {
      // look in order c:\temp, c:\tmp; else just use c:
      String path1 = "C:\\temp";
      File f = new File (path1);
      if (f.exists()) return path1; 
     
      String path2 = "C:\\Temp";
      f = new File (path2);
      if (f.exists()) return path2; 
    
      String path3 = "C:\\Tmp";
      f = new File (path3);
      if (f.exists()) return path3; 

      String path4 = "C:\\tmp";
      f = new File (path4);
      if (f.exists()) return path4; 

      return "C:"; 
   }

   private void removeFile (String pathName) {
      File f = new File(pathName);
      f.delete(); 
   }

  private void copyURL(String srcURL, String destFile)
  {
     try {
     PrivilegeManager.enablePrivilege("UniversalConnect");
     } catch (Exception e) { 
     System.out.println ("Can't enable file Privilege!!!"); 
     e.printStackTrace();
     }

     try {
     PrivilegeManager.enablePrivilege("UniversalFileAccess");
     } catch (Exception e) { 
     System.out.println ("Can't enable file Privilege!!!"); 
     e.printStackTrace();
     }

      try
      {
          URL  url  = new URL(srcURL);
          System.out.println("Opening connection to " + srcURL + "...");
          URLConnection urlC = url.openConnection();

          System.out.println("url.openStream . . .");
          InputStream is = url.openStream();

          System.out.print("Copying resource (type: " + urlC.getContentType());
          Date date=new Date(urlC.getLastModified());
          System.out.println(", modified on: " +
             date.toLocaleString() + ")...");
          System.out.flush();

          FileOutputStream fos=null;
          fos = new FileOutputStream( new File(destFile) );
          int oneChar, count=0;

          while ((oneChar=is.read()) != -1)
          {
             fos.write(oneChar);
             count++;
          }
          is.close();
          fos.close();

          System.out.println(count + " byte(s) copied");
      }
      catch (MalformedURLException e)
      { System.err.println(e.toString()); }
      catch (IOException e)
      { System.err.println(e.toString()); 
        e.printStackTrace();
      }
  }

}