Operating systems :
WINDOWS
FEDORA
SCIENTIFIC LINUX
DEBIAN

SWITCH

Tools:
CVS
TCPDUMP
NETCAT
NETBEANS
JAR
APPLET

rq: We prefer to use WEB START technology instead of APPLET. Java Web Start provides a platform-independent, secure, and robust deployment technology. It enables developers to deploy full-featured applications to end-users by making the applications available on a standard web server. With any web browser, end-users can launch the applications and be confident they always have the most-recent version :

It use the native JVE instead of the JVE of the browser.
It is easy to use with NETBEANS and trully simplify the librairies distribution and signature by certificate.
It seems to do what we really wanted to do using the APPLET.
It was advised to us by the JAVA computers scientist of the LPSC laboratory.

1 Introduction

An applet is a program written in the Java programming language that can be included in an HTML page, much in the same way an image is included in a page. You will find here some notes about the Netbeans tutorial.

2 Is-it really working ?

... sometime yes. Into NETBEANS do:

Open a new project called ``JavaApplication1''
Create a new JAppletForm file (from the Swing GUI Forms cathégory and call it NewJApplet.java

Add a color Chooser component to the pannel so as to have this code:

public class NewJApplet extends javax.swing.JApplet {

    /** Initializes the applet NewJApplet */
    public void init() {
        try {
            java.awt.EventQueue.invokeAndWait(new Runnable() {
                public void run() {
                    initComponents();
                }
            });
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void initComponents() {
        jColorChooser1 = new javax.swing.JColorChooser();

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jColorChooser1, javax.swing.GroupLayout.PREFERRED_SIZE, 
                  javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jColorChooser1, javax.swing.GroupLayout.PREFERRED_SIZE, 
                  javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
        );
    }
    private javax.swing.JColorChooser jColorChooser1;
}

Test this selected file with Maj-F6
Build the dist/JavaApplication1.jar with F11

Outside of NETBEANS:

Copy the JAR archive int /htdocs

Create the applet1.html file:

<applet 
 code=NewJApplet.class
 archive="JavaApplication1.jar"> 
 width=350 height=200 
</applet>

Now you should be able to load at this URL.

3 Signing the JAR file

Please try this second applet (doing like above) so as to test:

That your browser ask you for accepting our certificat.
That you cannot write to a file if you refuse it
That you can write to a file by accepting it

testing IO

import java.io.*;

public class NewJApplet extends javax.swing.JApplet {

    /** Initializes the applet NewJApplet */
    public void init() {
        try {
            java.awt.EventQueue.invokeAndWait(new Runnable() {
                public void run() {
                    initComponents();
                }
            });
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void initComponents() {

        jToggleButton1 = new javax.swing.JToggleButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();

        jToggleButton1.setText("test");
        jToggleButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jToggleButton1ActionPerformed(evt);
            }
        });

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jToggleButton1)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 323, 
                      javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(206, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jToggleButton1)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 155, 
                  javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(151, Short.MAX_VALUE))
        );
    }

    private void jToggleButton1ActionPerformed(java.awt.event.ActionEvent evt) {
          try {
              jTextArea1.append("testing...");
              BufferedWriter fichier = new BufferedWriter(new FileWriter("/tmp/tata.log"));
              fichier.write("bonjour tout le monde");
              fichier.newLine();
              fichier.close();
     } catch (Exception e){
	System.out.println(e.toString());
        jTextArea1.append(e.toString());
     }
     jTextArea1.append("done");
    }

    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextArea jTextArea1;
    private javax.swing.JToggleButton jToggleButton1;
}

keytool is delivered with Sun's development kit.
```
$ keytool -genkey -keyalg rsa -alias yourkey
```
Follow the instructions and type in all needed information.

Now we make the certificate:

$ keytool -export -alias yourkey -file yourcert.crt

Now we have to sign the applet:
```
$ jarsigner yourapplet.jar yourkey
```

Home

This document is also available in PDF and PostScript format.

2016-02-15

Contents

1 Introduction

2 Is-it really working ?

3 Signing the JAR file