Access Cookies from a Java Applet
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[edit] Implementations
[edit] Java
This Applet uses the package netscape.javascript.JSObject. To compile such program, you have to include in the CLASSPATH a special jar included in the JRE installation.
For Java 1.4.2 and later: add plugin.jar to your classpath when compiling. It can be found in the lib directory of your JRE installation, ex. C:\Program Files\Java\jre1.5.0\lib\plugin.jar
NOTE : For Java 1.4.0/1.4.1: use jaws.jar (same directory).
[HTML file (testCookie.html)]
<HTML><HEAD></HEAD><BODY> <APPLET CODE=TestCookie.class MAYSCRIPT HEIGHT=150 WIDTH=200> </APPLET></BODY></HTML>
[Java applet (TestCookie.java)]
import netscape.javascript.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class TestCookie extends Applet
implements ActionListener {
TextField tf1, tf2;
Button b1, b2, b3;
public void init() {
tf1 = new TextField(20);
tf2 = new TextField(20);
b1 = new Button("Write Cookie");
b2 = new Button("Read Cookie");
b3 = new Button("Delete Coookie");
setLayout(new FlowLayout());
add(tf1);
add(tf2);
add(b1);
add(b2);
add(b3);
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
}
public void actionPerformed(ActionEvent ae) {
if (ae.getSource() == b1) {
/*
** write a cookie
** computes the expiration date, good for 1 month
*/
java.util.Calendar c = java.util.Calendar.getInstance();
c.add(java.util.Calendar.MONTH, 1);
String expires = "; expires=" + c.getTime().toString();
String s1 = tf1.getText() + expires;
System.out.println(s1);
JSObject myBrowser = JSObject.getWindow(this);
JSObject myDocument = (JSObject) myBrowser.getMember("document");
myDocument.setMember("cookie", s1);
}
if (ae.getSource() == b2) {
/*
** read a cookie
*/
tf2.setText(getCookie());
}
if (ae.getSource() == b3) {
/*
** delete a cookie, set the expiration in the past
*/
java.util.Calendar c = java.util.Calendar.getInstance();
c.add(java.util.Calendar.MONTH, -1);
String expires = "; expires=" + c.getTime().toString();
String s1 = tf1.getText() + expires;
JSObject myBrowser = JSObject.getWindow(this);
JSObject myDocument = (JSObject) myBrowser.getMember("document");
myDocument.setMember("cookie", s1);
}
}
public String getCookie() {
/*
** get all cookies for a document
*/
try {
JSObject myBrowser = (JSObject) JSObject.getWindow(this);
JSObject myDocument = (JSObject) myBrowser.getMember("document");
String myCookie = (String)myDocument.getMember("cookie");
if (myCookie.length() > 0)
return myCookie;
}
catch (Exception e){
e.printStackTrace();
}
return "?";
}
public String getCookie(String name) {
/*
** get a specific cookie by its name, parse the cookie.
** not used in this Applet but can be useful
*/
String myCookie = getCookie();
String search = name + "=";
if (myCookie.length() > 0) {
int offset = myCookie.indexOf(search);
if (offset != -1) {
offset += search.length();
int end = myCookie.indexOf(";", offset);
if (end == -1) end = myCookie.length();
return myCookie.substring(offset,end);
}
else
System.out.println("Did not find cookie: "+name);
}
return "";
}
}
You can try it here. See this text file with some useful Javascript functions for cookies handling.
Check this http://www.rgagnon.com/javadetails/java-0303.html How-to to detect ]if Cookies are enabled or not.
