We may replace php app with j2ee app, but the problem is we wanna replace the modules one by one, which means two apps would co-exist and communicate with each other.
So is it possible to share the user session between the 2 apps? Or use cookie to solve the problem?
Save your session data to a database with session_set_save_handler().
UPDATE Efficiency wise it would be very mininal, the difference from reading a text file to querying a database (presumably using an existing connection).
Some example code (simplified from what I use)
class Session {
public function __construct() {
session_start();
$this->clean();
}
public function __destruct() {
session_write_close();
}
public function open() {
return TRUE;
}
public function close() {
return TRUE;
}
public function read($id) {
global $Database;
if ($Database->select('session_data FROM sessions WHERE session_id="%s"', $id)) {
list($data) = $Database->fetch(MYSQL_NUM);
return $data;
} else {
return '';
}
}
public function write($id, $data) {
global $Database;
return $Database->replace('sessions SET session_id="%s", session_data="%s", session_updated=%d', array($id, $data, time()));
}
public function destroy($id) {
global $Database;
$_SESSION = array();
return $db->delete('sessions WHERE session_id="%s"', $id);
}
public function clean($expire = 600) {
global $Database;
$Database->delete('FROM sessions WHERE session_updated<%d', $time - $expire);
return TRUE;
}
}
// Declare the functions to use:
session_set_save_handler(array('Session', 'open'), array('Session', 'close'), array('Session', 'read'), array('Session', 'write'), array('Session', 'destroy'), array('Session', 'clean'));
$Session = new Session;
The you can read/write to the session data using $_SESSION['name'] = data; in the usual technique.
One option you might want to look at is Quercus which is tied into Resin, and allows you to run PHP code on a J2EE app server, and enables some communication between the 2 platforms.
Sharing a regular Java EE session with PHP can be done very efficient and fast with PHP-java-bridge.
This solution offer superior performance over using a database as it does not generate any disk IO. It also does not need any changes on the PHP webserver or Java EE server. Just add some code, configure and you're done.
Setting up the php-java-bridge can be confusing, but if you know how to do it, it's only a 10-minute job. As I just did a proof of concept my self I can hand you the cookbook solutions:
Download PHP-java-bridge files. I downloaded JavaBridgeTemplate610.zip (for the needed jar files) and php-java-bridge_6.1.0_documentation.zip for the needed examples, php include file and sample code (session sharing!).
Add the "JavaBridge.jar", "php-script.jar" and "php-servlet.jar" to you're webapp by putting it in the "/WEB-INF/lib/" of you're Java EE server.
Add a "test.jsp" to you're Java EE servers "/web" directory:
<HTML>
<TITLE>PHP and JSP session sharing</title>
<BODY>
<%
javax.servlet.http.HttpSession $session = request.getSession();
if($session.getAttribute("counter")==null) {
$session.setAttribute("counter", new java.lang.Integer(1));
}
int $counter = ((java.lang.Integer)$session.getAttribute("counter")).intValue();
out.println ("HttpSession variable \"counter\": " + $counter + "<br>");
java.lang.Integer $next = new java.lang.Integer($counter+1);
session.setAttribute("counter", $next);
%>
<a href="http://127.0.0.1/test.php">PHP page</a>
</BODY>
</HTML>
Configure the JavaBridge servlet so it can be used by PHP to communicate to the Java EE server. Just add the following lines to you're web.xml:
<servlet>
<servlet-name>PhpJavaServlet</servlet-name>
<servlet-class>php.java.servlet.PhpJavaServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>PhpJavaServlet</servlet-name>
<url-pattern>*.phpjavabridge</url-pattern>
</servlet-mapping>
Add a file named "test.php" to you're webserver root and make sure you edit the JAVA_HOSTS and JAVA_SERVLET to correctly point to the Javabridgeservlet as configured in the web.xml.
<?php
define ("JAVA_HOSTS", "127.0.0.1:8084");
define ("JAVA_SERVLET", "/JavaBridge.phpjavabridge");
require_once("java/Java.inc");
$session = java_session();
?>
<HTML>
<TITLE>PHP and JSP session sharing</title>
<BODY>
<?php
if(is_null(java_values($session->get("counter")))) {
$session->put("counter", 1);
}
$counter = java_values($session->get("counter"));
print "HttpSession variable \"counter\": $counter<br>\n";
$session->put("counter", $counter+1);
?>
<a href="http://127.0.0.1:8084/test.jsp">JSP page</a>
</BODY>
</HTML>
Install the needed "java.inc" php include file. You will find the file in the downloaded "php-java-bridge_6.1.0_documentation.zip" in the src.zip. Copy the "java.inc" file in the "/java" directory (just this one php file!).
Restart Application server
Start the test.php script (for example goto: http://127.0.0.1/test.php)
If you click on the links to the jsp and php file back, you will notice that the counter shares the Java session between both JSP and PHP scripts!
In order to share the same JSession cookie in a JSP/Servlet and PHP they both need to run on the same domain name (also make sure that JAVA_HOSTS is the PHP file uses the same domain name!).