Session handling between android class and php

you can create a Singleton to DefaultHttpClient, then you use this to all your connections, before you send a HTTPRequest...

Like this:

public class SessionControl {
static private HttpClient httpclient = null;

public static HttpClient getHttpclient() {
    if( httpclient == null){
        SessionControl.setHttpclient(new DefaultHttpClient());
    }
    return httpclient;
}

public static void setHttpclient(HttpClient httpclient) {
    SessionControl.httpclient = httpclient;
}

}

then, when you call HttpClient, You do this:

HttpClient httpclient = SessionControl.getHttpclient();

From your question it seems that you want to store the PHPSESSID between DefaultHttpClient calls.

You may try to use: HttpClientParams.setCookiePolicy(params, CookiePolicy.BROWSER_COMPATIBILITY);

when setting the params to your DefaultHttpClient instances. Otherwise you could manually get that session id and append it in every request.

Well you might be creating some kind of session id on server side, which mobile application retrives and stores for futher use. Then everytime application connects to server it gives this id in parameter ( www.example.com?id=some_id ).

EDIT

Here is tutorial on connection to PHP server from Android device. It is not describing how to create ID, but as you can handle connection I am sure you will be able to create ID and store it in database link.

One more thing, to retrive parameter in given URL (www.example.com?id=some_id) in PHP you have to use $_REQUEST['id'] varible. If you want to send more parameters within given URL separete it with "&" sign (www.example.com?id=some_id&id2=some_id).

Be sure to check what is send in parameter, as someone might use your parameter for SQL injection purposes.