*--------------------------------------------------
* Cookie.java
*
* Pass a cookie (stored in rms) between the MIDlet
* and a Java servlet. The cookie is generated
* by the servlet on the first visit.
*
* Example from the book: Core J2ME Technology
* Copyright John W. Muchow http://www.CoreJ2ME.com
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.rms.*;
import javax.microedition.io.*;
import java.io.*;
public class Cookie extends MIDlet implements CommandListener
{
private Display display;
private TextBox tbMain;
private Form fmMain;
private Command cmExit;
private Command cmLogon;
private String cookie = null;
private RecordStore rs = null;
static final String REC_STORE = "rms_cookie";
private String url = "http://www.mycgiserver.com/servlet/corej2me.CookieServlet";
public Cookie()
{
display = Display.getDisplay(this);
// Create commands
cmExit = new Command("Exit", Command.EXIT, 1);
cmLogon = new Command("Logon", Command.SCREEN, 2);
// Create the form, add commands, listen for events
fmMain = new Form("");
fmMain.addCommand(cmExit);
fmMain.addCommand(cmLogon);
fmMain.setCommandListener(this);
// Read cookie if available
openRecStore();
readCookie();
// System.out.println("Client cookie: " + cookie);
}
public void startApp()
{
display.setCurrent(fmMain);
}
public void pauseApp()
{ }
public void destroyApp(boolean unconditional)
{
closeRecStore(); // Close record store
}
public void openRecStore()
{
try
{
// The second parameter indicates that the record store
// should be created if it does not exist
rs = RecordStore.openRecordStore(REC_STORE, true);
}
catch (Exception e)
{
db("open " + e.toString());
}
}
public void closeRecStore()
{
try
{
rs.closeRecordStore();
}
catch (Exception e)
{
db("close " + e.toString());
}
}
/*--------------------------------------------------
* Write cookie to rms
*-------------------------------------------------*/
public void writeRecord(String str)
{
byte[] rec = str.getBytes();
try
{
rs.addRecord(rec, 0, rec.length);
}
catch (Exception e)
{
db("write " + e.toString());
}
}
/*--------------------------------------------------
* Read cookie from rms
*-------------------------------------------------*/
public void readCookie()
{
try
{
byte[] recData = new byte[25];
int len;
if (rs.getNumRecords() > 0)
{
// Only one record will ever be written, safe to use '1'
if (rs.getRecordSize(1) > recData.length)
recData = new byte[rs.getRecordSize(1)];
len = rs.getRecord(1, recData, 0);
cookie = new String(recData);
}
}
catch (Exception e) {
db("read " + e.toString());
}
}
/*--------------------------------------------------
* Send client request and recieve server response
*
* Client: If cookie exists, send it to the server
*
* Server: If cookie is sent back, this is the
* clients first request to the server. In
* that case, save the cookie. If no cookie
* sent, display server body (which indicates
* the last time the MIDlet contacted server).
*-------------------------------------------------*/
private void connect() throws IOException
{
InputStream iStrm = null;
ByteArrayOutputStream bStrm = null;
HttpConnection http = null;
try
{
// Create the connection
http = (HttpConnection) Connector.open(url);
//----------------
// Client Request
//----------------
// 1) Send request method
http.setRequestMethod(HttpConnection.GET);
// If you experience connection/IO problems, try
// removing the comment from the following line
//http.setRequestProperty("Connection", "close");
// 2) Send header information
if (cookie != null)
http.setRequestProperty("cookie", cookie);
System.out.println("Client cookie: " + cookie);
// 3) Send body/data - No data for this request
//----------------
// Server Response
//----------------
// 1) Get status Line
if (http.getResponseCode() == HttpConnection.HTTP_OK)
{
// 2) Get header information
String tmpCookie = http.getHeaderField("set-cookie");
System.out.println("server cookie: " + tmpCookie);
// Cookie will only be sent back from server only if
// client (us) did not send a cookie in the first place.
// If a cookie is returned, we need to save it to rms
if (tmpCookie != null)
{
writeRecord(tmpCookie);
// Update the MIDlet cookie variable
cookie = tmpCookie;
fmMain.append("First visit\n");
fmMain.append("Client : " + cookie + "\n");
}
else // No cookie sent from server
{
// 3) Get data, which is the last time of access
iStrm = http.openInputStream();
int length = (int) http.getLength();
String str;
if (length != -1)
{
byte serverData[] = new byte[length];
iStrm.read(serverData);
str = new String(serverData);
}
else // Length not available...
{
bStrm = new ByteArrayOutputStream();
int ch;
while ((ch = iStrm.read()) != -1)
bStrm.write(ch);
str = new String(bStrm.toByteArray());
}
// Append data to the form
fmMain.append("Last access:\n" + str + "\n");
}
}
}
finally
{
// Clean up
if (iStrm != null)
iStrm.close();
if (bStrm != null)
bStrm.close();
if (http != null)
http.close();
}
}
/*--------------------------------------------------
* Process events
*-------------------------------------------------*/
public void commandAction(Command c, Displayable s)
{
// If the Command button pressed was "Exit"
if (c == cmExit)
{
destroyApp(false);
notifyDestroyed();
}
else if (c == cmLogon)
{
try
{
// Logon to the servlet
connect();
}
catch (Exception e)
{
