Load text file into applet

Question

hi,
I am new to java and really need some help.
I want to load / read a text file in my applet line by line
the text file looks like:
P,161,127,3,ff6599c2
P,161,127,3,ff6599c2
P,161,128,3,ff6599c2
P,161,129,3,ff6599c2
etc.
the code I tied and did not work looks like:
class read
     public void main( String[] args)
          int i;
          if (args.length < 1)
               System.out.println("Please enter file: read<datei>");
               System.exit(-1);
          try
               BufferedReader in =new BufferedReader(new FileReader( args[0]));
               String line = new String();
               while((line=in.readLine())!=null)
                    System.out.println( line );
          catch(IOException e2)
has anybody an idea how to do it?
Thanks a lot
Silke

Answer 1

<PRE>
First off you need to create a class which extends the
Applet class. The applet class does not have the
method "public static void main(String args[])". Instead it has a method "init()". In the "init" method you should
write the code that you would write in "main". The "init"
method is only executed once. When the applet is first downloaded. Here is a sample code, but there is one other factor to note. Applets have trouble accessing
files on computers. This goes above and beyond the
applet sandbox which locks up an applet. In my experiences I have only managed to read and write text
files to the desktop through applets. The program can
be used by entering the file name in the text field
at the top of the applet and then clicking the "Read File"
button at the bottom of the applet. This code segment is untested and it has been some time since I have done
applet programming but it should work. You may have to
edit the security policy file(security.policy) to grant permission to your codebase before this functions properly because it involves reading from the file system. The grant should look something like this(if you are running under unix/linux I believe you would substitute"file:\\\" with "file:/"):
grant codeBase "file:\\\<Directory Path that contains
the MyApplet class" {
java.io.FilePermission "read", "*"
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
<Applet Code="MyApplet" width="300", height="300">
</Applet>
class MyApplet extends Applet
implements ActionListener {
TextArea ta=new TextArea();
Button readFB=new Button("Read File");
TextField tf=new TextField();
public void init() {
setLayout(new BorderLayout());
Panel tempPan=new Panel();
tempPan.setLayout(new BorderLayout());
tempPan.add("West", new Label("File Name:"));
tempPan.add("Center", tf);
add("North", tempPan);
add("Center", ta);
add("South", readFB);
readFB.addActionListener(this);
setSize(300, 300);
show();
public void actionPerformed(ActionEvent ae) {
String action=ae.getActionCommand();
if(action.equals("Read File")) {
String strFileName=tf.getText();
BufferedReader br=new BufferedReader(new FileReader(new File(strFileName)));
ta.setText("");
String nextLine="";
while((nextLine=br.readLine())!=null) {
ta.append(nextLine+"\n");
br.close();
ps: be careful when modifying security policy file.
It will affect all applet code that is loaded from the
codeBase specified. If no codeBase is specified it
will apply to all codeBases leaving you vulnerable
to malicious applets. Good luck.
</PRE>